Fossils - Dinosaurs - Ancient Life - Paleontology Thread

[Resurgence]

A Paleontology eBook Pack on The Pirate Bay:



Torrent Name: ammonites, trilobites, pterosaurs, and more


The Torrent File Contents:


Trilobites.pdf

Trilobites of New York.pdf

The Ecology of Fossils-- an Illustrated Guide.pdf

Ammonites and Other Cephalopods of the Pierre Seaway.pdf

The Complete T rex.pdf

The Pterosaurs-- From Deep Time.pdf

Seismosaurus-- The Earth Shaker.pdf

Oceans of Kansas-- A Natural History of the Western Interior Sea.pdf

Ammonites.pdf

The Horned Dinosaurs.pdf

Sea Dragons-- Predators of the Prehistoric Oceans.pdf

Trilobite! Eyewitness to Evolution.pdf

Trilobites in Wales.pdf


Location (Alternate location for the magnet link - The Pirate Bay is inaccessible at the time of this writing):

https://btdb.to/torrent/OVQdWbXAGqc5jplE...IPrGv.html



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A giant new species of mammal-like reptile from the Triassic discovered



Lisowicia bojani.




Paleontologists in Poland have found fossil fragments from a giant new species of mammal-like reptile that walked the Earth approximately 237 million years ago (Late Triassic epoch).

Named Lisowicia bojani, the ancient creature belongs to Dicynodontia (dicynodonts), a group of plant-eating, mammal-like reptiles.

“Dicynodonts were among the most abundant and diverse synapids — early four-legged land vertebrates that gave rise to modern-day mammals — from the middle Permian (around 299 to 251 million years ago) to the early Late Triassic (around 237 million years ago),” said Dr. Tomasz Sulej from Poland’s Institute of Paleobiology and Dr. Grzegorz Niedzwiedzki of Uppsala University.

“Fossils of Triassic dicynodonts are extremely abundant in African, Asian, and North and South Americans deposits but are comparatively poorly known from the other regions like Europe.”

“Lisowicia bojani fossils are the first substantial dicynodont finds from European deposits.”

Lisowicia bojani reached an estimated length of more than 14.7 feet (4.5 m), height of 8.5 feet (2.6 m), and body mass of 9 tons.

It had erect-gait forelimbs, suggesting upright limb posture, like that of modern large mammals such as rhinoceroses and hippopotami. Previously, Triassic dicynodonts were characterized only with sprawling forelimbs (the gait of reptiles).

“The find of Lisowicia bojani shows that at least one dicynodont lineage also participated in the ‘push for gigantism’ at the same time as the sauropodomorphs, but also suggests that their evolutionary history in the Late Triassic is poorly documented,” the paleontologists said.

“This discovery changes our ideas about the latest history of dicynodonts, mammal Triassic relatives,” Dr. Sulej said.

“It also raises far more questions about what really make them and dinosaurs so large.”

“Dicynodonts were amazingly successful animals in the Middle and Late Triassic. Lisowicia bojani is the youngest dicynodont and the largest non-dinosaurian terrestrial tetrapod from the Triassic,” Dr. Niedzwiedzki added.

“It’s natural to want to know how dicynodonts became so large. Lisowicia bojani is hugely exciting because it blows holes in many of our classic ideas of Triassic ‘mammal-like reptiles’.”



http://www.sci-news.com/paleontology/ele...06649.html



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Oxygen could have been available to life as early as 3.5 billion years ago



Spherical colony of cyanobacteria.




Microbes could have performed oxygen-producing photosynthesis at least one billion years earlier in the history of the Earth than previously thought.

The finding could change ideas of how and when complex life evolved on Earth, and how likely it is that it could evolve on other planets.

Oxygen in the Earth's atmosphere is necessary for complex forms of life, which use it during aerobic respiration to make energy.

The levels of oxygen dramatically rose in the atmosphere around 2.4 billion years ago, but why it happened then has been debated. Some scientists think that 2.4 billion years ago is when organisms called cyanobacteria first evolved, which could perform oxygen-producing (oxygenic) photosynthesis.

Other scientist think that cyanobacteria evolved long before 2.4 billion years ago but something prevented oxygen from accumulating in the air.

Cyanobacteria perform a relatively sophisticated form of oxygenic photosynthesis -- the same type of photosynthesis that all plants do today. It has therefore been suggested that simpler forms of oxygenic photosynthesis could have existed earlier, before cyanobacteria, leading to low levels of oxygen being available to life.

Now, a research team led by Imperial College London have found that oxygenic photosynthesis arose at least one billion years before cyanobacteria evolved. Their results, published in the journal Geobiology, show that oxygenic photosynthesis could have evolved very early in Earth's 4.5-billion-year history.

Lead author Dr Tanai Cardona, from the Department of Life Sciences at Imperial, said: "We know cyanobacteria are very ancient, but we don't know exactly how ancient. If cyanobacteria are, for example, 2.5 billion years old that would mean oxygenic photosynthesis could have started as early as 3.5 billion years ago. It suggests that it might not take billions of years for a process like oxygenic photosynthesis to start after the origin of life."

If oxygenic photosynthesis evolved early, it could mean it is a relatively simple process to evolve. The probability of complex life emerging in a distant exoplanet may then be quite high.

It is difficult for scientists to figure out when the first oxygen-producers evolved using the rock record on Earth. The older the rocks, the rarer they are, and the harder it is to prove conclusively that any fossil microbes found in these ancient rocks used or produced any amount of oxygen.

Instead, the team investigated the evolution of two of the main proteins involved in oxygenic photosynthesis.

In the first stage of photosynthesis, cyanobacteria use light energy to split water into protons, electrons and oxygen with the help of a protein complex called Photosystem II.

Photosystem II is made up of two proteins called D1 and D2. Originally, the two proteins were the same, but although they have very similar structures, their underlying genetic sequences are now different.

This shows that D1 and D2 have been evolving separately -- in cyanobacteria and plants they only share 30 percent of their genetic sequence. Even in their original form, D1 and D2 would have been able to perform oxygenic photosynthesis, so knowing how long ago they were identical could reveal when this ability first evolved.

To find out the difference in time between D1 and D2 being 100 percent identical, and them being only 30 percent the same in cyanobacteria and plants, the team determined how fast the proteins were changing -- their rate of evolution.

Using powerful statistics methods and known events in the evolution of photosynthesis, they determined that the D1 and D2 proteins in Photosystem II evolved extremely slowly -- even slower than some of the oldest proteins in biology that are believed to be found in the earliest forms of life.

From this, they calculated that the time between the identical D1 and D2 proteins and the 30 percent similar versions in cyanobacteria and plants is at least a billion years, and could be more than that.

Dr Cardona said: "Usually, the appearance of oxygenic photosynthesis and cyanobacteria are considered to be the same thing. So, to find out when oxygen was being produced for the first time researchers have tried to find when cyanobacteria first evolved.

"Our study instead shows that oxygenic photosynthesis likely got started long before the most recent ancestor of cyanobacteria arose. This is in agreement with current geological data that suggests that whiffs of oxygen or localized accumulations of oxygen were possible before three billion years ago.
"Therefore, the origin of oxygenic photosynthesis and the ancestor of cyanobacteria do not represent the same thing. There could be a very large gap in time between one and the other. It is a massive change in perspective."
Now, the team are trying to recreate what the photosystem looked like before D1 and D2 evolved in the first place. Using the known variation in photosystem genetic codes across all species alive today, they are trying to piece together the ancestral photosystem genetic code.



https://www.sciencedaily.com/releases/20...131552.htm



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Giant flightless birds were nocturnal and possibly blind



Giant nocturnal elephant birds are shown foraging in the ancient forests of Madagascar at night.




If you encountered an elephant bird today, it would be hard to miss. Measuring in at over 10 feet tall, the extinct avian is the largest bird known to science. However, while you looked up in awe, it's likely that the big bird would not be looking back.

According to brain reconstruction research led by The University of Texas at Austin, the part of the elephant bird brain that processed vision was tiny, a trait that indicates they were nocturnal and possibly blind.

A nocturnal lifestyle is a trait shared by the elephant bird's closest living relative, the kiwi -- a practically blind, chicken-size denizen of New Zealand -- and a clue that is helping scientists learn more about the elephant bird's behavior and habitat, said Christopher Torres, a Ph.D. candidate who led the research.

"Studying brain shape is a really useful way of connecting ecology -- the relationship between the bird and the environment -- and anatomy," Torres said.

"Discoveries like these give us tremendous insights into the lives of these bizarre and poorly understood birds."

Elephant birds were large, flightless and lived in what is now Madagascar until a mixture of habitat loss and potential human meddling led to their demise between 500 and 1,000 years ago.

"Humans lived alongside, and even hunted, elephant birds for thousands of years," Torres said. "But we still know practically nothing about their lives. We don't even really know exactly when or why they went extinct."

Scientists had previously assumed that elephant birds were similar to other big, flightless birds, like emus and ostriches -- both of which are active during the day and have good eyesight. But Torres and Clarke revealed that elephant birds had distinctly different lifestyles through reconstructions of their brains.

Bird skulls wrap tightly around their brains, with the turns and curves of the bone corresponding to brain structures. The researchers studied the skulls of two species of elephant birds. By using CT-imaging data of the two elephant bird skulls, the researchers were able to create digital brain reconstructions called endocasts. In addition to the elephant bird skulls, the researchers also created endocasts for close relatives of the elephant bird, both living and extinct.

In both elephant bird skulls, the optic lobe -- a bundle of brain nerves that controls eyesight -- was very small, with the structure almost absent in the larger species. The lobe had the most in common with that of a kiwi, which Torres said came as a "total shock" because of the kiwi's poor vision and nocturnal behavior.

"No one has ever suspected that elephant birds were nocturnal," Torres said. "The few studies that speculated on what their behavior was like explicitly assumed they were active during the day."

Andrew Iwaniuk, an associate professor at the University of Lethbridge and an expert on brain evolution in birds who was not involved with the research, said that he had a similar reaction to the findings.

"I was surprised that the visual system is so small in a bird this big," he said. "For a bird this large to evolve a nocturnal lifestyle is truly bizarre and speaks to an ecology unlike that of their closest relatives or any other bird species that we know of."

In addition to vision, the endocasts rendering of the olfactory bulb -- the part of the brain that processes the sense of smell -- helped shed light on the habitats where elephant birds lived. The larger of the two species of elephant bird had a large olfactory bulb, a trait associated with forest dwelling. In contrast, the smaller elephant bird species had a smaller olfactory bulb, possibly indicating that it lived in grasslands. The smaller species also appears to have somewhat keener vision, which means it may have been more active at dusk than during the pitch black of night.

"Details like these not only tell us about what the lives of elephant birds were like, but also what life in general was like on Madagascar in the distant past," Clarke said. "As recently as 500 years ago, very nearly blind, giant flightless birds were crashing around the forests of Madagascar in the dark. No one ever expected that."



https://www.sciencedaily.com/releases/20...101018.htm



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Modern birds inherited colored eggs from their dinosaur ancestors, study says



A nesting cassowary-like dinosaur named Beibeilong sinensis in the act of incubating eggs.



The colors found in modern birds’ eggs did not evolve independently, as previously thought, but evolved instead from dinosaurs. This is an artist’s impression of the oviraptorid dinosaur Huanansaurus ganzhouensis.




Modern birds inherited their egg color from non-avian dinosaur ancestors that laid eggs in fully or partially open nests, according to new research led by Yale University researcher Jasmina Wiemann.

“This completely changes our understanding of how egg colors evolved,” said Wiemann, a paleontologist in the Department of Geology & Geophysics at Yale University.

“For two centuries, ornithologists assumed that egg color appeared in modern birds’ eggs multiple times, independently.”

The egg colors of birds reflect characteristic preferences in nesting environments and brooding behaviors.

Modern birds use only two pigments — blue-green biliverdin and red-brown protoporphyrin IX — to create all of the various egg colors, spots, and speckles.

Wiemann and her colleagues from the American Museum of Natural History and the University of Bonn analyzed 18 fossil dinosaur eggshell samples from around the world, using non-destructive laser microspectroscopy to test for the presence of the two eggshell pigments.

They found the pigments in eggshells belonging to Eumaniraptoran dinosaurs, which include small, carnivorous dinosaurs such as Velociraptor.

“We infer that egg color co-evolved with open nesting habits in dinosaurs,” Wiemann explained.

“Once dinosaurs started to build open nests, exposure of the eggs to visually hunting predators and even nesting parasites favored the evolution of camouflaging egg colors, and individually recognizable patterns of spots and speckles.”



Egg colors of archosaurs: the internal nodes are (1) Archosauria, (2) Dinosauria, (3) Ornithischia, (4) Saurischia, (5) Eumaniraptora, (6) Paraves and (7) Aves; the egg icon in the phylogeny labels Eumaniraptora. All species are represented by an icon indicating egg shape, and an example of reconstructed color. If eggshell pigments are present, the area below the spectral function is colored in blue (biliverdin) or orange (protoporphyrin IX), and all pigment bands are labeled with either blue (biliverdin) or red (protoporphyrin IX) dots. Photographs show the samples and nest icons encode three nesting strategies: buried, (partially) open ground and open tree nesting. AU – arbitrary units.




“Colored eggs have been considered a unique bird characteristic for over a century,” said co-author Dr. Mark Norell, the Macaulay Curator of Paleontology at the American Museum of Natural History.

“Like feathers and wishbones, we now know that egg color evolved in their dinosaur predecessors long before birds appeared.”



http://www.sci-news.com/paleontology/col...06567.html



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Paleoworld


Season 1, Episode 8 - "Attack of the Killer Kangaroos"

[nazmouille]

Wow, that's quite a topic, so full of info.
I wanted to comment a month ago when I read the first post but the message didn"t appear as others didn't too.

I myself is also into fossils, sea animals and mostly invertebrates to be precise, one exception being the plesiosaur, as it's the only "dinosaur" I can find fossils of.

Thank you for this collection of litterature on dinosaurs. Do you prospect for fossils as well? Maybe we could trade some fossils!

I'll try to post a more useful message soon as I don't really have time tonight

[Resurgence]

nazmouille,


You're welcome.

I'm glad that you are enjoying the thread.

There is a torrent available that you may find interesting.


Torrent Name: Treatise on Invertebrate Paleontology

Magnet Link:

http://magnet4you.me/magnet/4338961


Enjoy!



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Update:


In post #11, I provided a link for a paleontology Ebook pack. The site referenced is down.

Since The Pirate Bay is also inaccessible at the moment, here is an alternate location for the magnet link:


http://magnet4you.me/magnet/5406831



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Early Pioneers in Paleontology:



Nicolas Steno



Portrait of Nicolas Steno (1666–1677). Unsigned but attributed to court painter Justus Sustermans.



 
Nicolas Steno (Danish: Niels Steensen; Latinized to Nicolaus Steno or Nicolaus Stenonius; 1 January 1638 – 25 November 1686, [NS: 11 January 1638 – 5 December 1686]) was a Danish scientist, a pioneer in anatomy and geology. He was trained in the classical texts on science; however, by 1659 he seriously questioned accepted knowledge of the natural world. Importantly he questioned explanations for tear production, the idea that fossils grew in the ground and explanations of rock formation. His investigations and his subsequent conclusions on fossils and rock formation have led scholars to consider him one of the founders of modern stratigraphy and modern geology.

During the 17th century, the guiding principles of paleontology and historical geology began to emerge in the work of a few individuals. Steno presented carefully reasoned arguments favoring the organic origin of what are now called fossils. Actually, Leonardo da Vinci argued that fossils were the remains of once-living organisms more than a century before Steno, but Steno elucidated principles that made possible the reconstruction of certain kinds of geologic events in a chronological order.

In his Canis carcariae dissectum caput (1667; “Dissected Head of a Dog Shark”), he concluded that large tongue-shaped objects found in the strata of Malta were the teeth of sharks, whose remains were buried beneath the seafloor and later raised out of the water to their present sites. This excursion into paleontology led Steno to confront a broader question. How can one solid body, such as a shark’s tooth, become embedded in another solid body, such as a layer of rock? He published his answers in 1669 in a paper titled “De solido intra naturaliter contento dissertationis” (“A Preliminary Discourse Concerning a Solid Body Enclosed by Processes of Nature Within a Solid”). Steno cited evidence to show that when the hard parts of an organism are covered with sediment, it is they and not the aggregates of sediment that are firm. Consolidation of the sediment into rock may come later, and, if so, the original solid fossil becomes encased in solid rock. He recognized that sediments settle from fluids layer by layer to form strata that are originally continuous and nearly horizontal. His principle of superposition of strata states that in a sequence of strata, as originally laid down, any stratum is younger than the one on which it rests and older than the one that rests upon it. 










Born to a Lutheran family, Steno converted to Catholicism in 1667. After his conversion, his interest for natural sciences rapidly waned giving way to his interest in theology. At the beginning of 1675, he decided to become a priest. Four months after, he was ordained in the Catholic clergy in Easter 1675. As a clergyman, he was later appointed Vicar Apostolic of Nordic Missions and Titular Bishop of Titopolis by Pope Innocent XI. The canonization process for him was begun in 1938. Pope John Paul II beatified Steno in 1988.
[url=https://en.wikipedia.org/wiki/Nicolas_Steno#cite_note-17][/url]



Portrait of Steno as Bishop.




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Tracing the evolutionary origins of fish to shallow ocean waters



Coral reefs are envisioned as the seats of great biodiversity, but they may not be where all that diversity got its start. Paleobiologists reveal that the earliest fish may have diversified in shallower waters near shore.

The first vertebrates on Earth were fish, and scientists believe they first appeared around 480 million years ago. But fossil records from this time are spotty, with only small fragments identified. By 420 million years ago, however, the fossil record blossoms, with a huge variety of fish species present en masse.

"It's been this ongoing question of, well, where were they?" says Lauren Sallan, a paleobiologist at the University of Pennsylvania. "Where were they hiding? What were their environmental origins?"

Sallan Ivan J. Sansom of the University of Birmingham and colleagues are the first to present a wealth of evidence to answer that question.
And the answer, it seems, is near shore, the areas often describe as the intertidal zone, or shallow lagoons.

"In modern conceptions, we see that coral reefs are so important for fish biodiversity, so we assume there's an ancient link between fishes and reefs going back to the beginning," says Sallan. "But decades of searching in places like the Cincinnati Arch have come up empty."

"Instead, our work shows that almost every major vertebrate division, from the earliest armored jawless fish all the way up through sharks and our own ancestors, all started out right near the beach, far inshore of the reef. Even as older groups spread out, newer groups were also appearing at the shoreline."

The findings help explain important features of the fossil record, such as why so few early fish fossils are found intact; the wave action of the shallow ocean area likely blasted them into tiny fragments. It also helps scientists make sense of the fact that, over evolutionary time, many fish groups moved from ocean water to freshwater with some becoming freshwater fish while others evolved into the earliest tetrapods, land-dwelling vertebrates.

"They often went to freshwater before the reefs, which is almost an independent line of evidence that they would have had to have been close to shore before doing so," Sallan says.

Exactly where vertebrates originated and diversified has been a hotly debated subject in paleontology. Certain groups of fossils from this key period in the middle Paleozoic Era told one story -- perhaps a freshwater site of origin -- while other groups may point to a birthplace in the open ocean, and still others popped up in other habitat types. Further complicating matters, the origin story of invertebrate biodiversity seem settled: They diversified around coral reefs, their descendants subsequently striking out to inhabit shallower or deeper waters.

Sallan, Sansom, and colleagues decided to investigate the question for vertebrates using a big-data approach.

"The nice thing about the fossil record is that we often find fishes in the context of where they live," Sallan says. "The rock that holds them tells us what their environment looked like, whether it was reef, shallow water, deep water, a riverbed, or a lake."

Bringing that environmental context together with what was already known about the family tree relationships of vertebrates from the middle Paleozoic, 480 to 360 million years ago, the researchers created a database that involved 2,728 early records for jawed and jawless fishes.

"It's a really huge new dataset," says Sallan.

The team was then able to reconstruct the missing information in the fossil record using mathematical modeling, allowing them to make informed predictions about the habitat type in which the earliest ancestors of various vertebrate groups emerged.

"For vertebrates, we find that they're originating in this unexpected, really restricted shallow area of the oceans," Sallan says. "And they stay in this limited area for a long time after they emerge."

As they remained in the shallows, however, they gained a variety of adaptations that enabled them to compete with the others in a shared habitat. The researchers noted that many groups acquired traits that made them well-suited for life either as bottom-dwellers, or for a free-swimming ecology out in the ocean's deeper waters.

A similar divergence has been seen in modern fish, such as sticklebacks, which evolved a bottom-dwelling and a free-swimming form from common ancestors in more recent times.

No one has done a similarly comprehensive study on living vertebrate species, however. "One of the things we want to know is whether these shallow waters are still the biological pump that is feeding the reef," Sallan says. "Where is the current site of innovation?"

If that were the case, there may be some small consolation in the face of mass reef die-offs around the world; maybe shallow waters will continue to be the cradle of diversification for fish, allowing biodiversity to persist despite a paucity of reef habitat.



https://www.sciencedaily.com/releases/20...141939.htm



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Earth's oldest animals formed complex ecological communities



Ediacara biota were forming complex communities tens of millions of years before the Cambrian explosion.

A new analysis is shedding light on Earth's first macroscopic animals: the 570-million-year-old, enigmatic Ediacara biota.

Ediacaran fossils have a slightly bizarre appearance not shared by any modern animal groups. For decades, researchers believed these enigmatic fossils were ecologically simple. However, borrowing a method from modern ecology -- fitting species to relative abundance distributions -- Vanderbilt University paleontologist Simon A.F. Darroch and his team learned that these organisms were more like modern animals than once thought.

The analyses showed that a majority of fossil assemblages bear the hallmarks of being ecologically complex, and Ediacara biota were forming complex communities tens of millions of years before the Cambrian explosion. The creatures lived partially submerged in what was once the ocean floor, some of them suspension feeding, others filter feeding, still others passively absorbing nutrition. A few were even mobile.

Complex communities are ones that comprise species competing for numerous different resources or species that create niches for others (as in many modern-day ecosystems). The team found that the signature of complex communities extends all the way back to the oldest Ediacaran fossils. In other words, as soon as macroscopic life evolved, it began forming diverse ecological communities not unlike those in the present day.

"The main impact of our work was testing between the simple and complex models for Ediacaran ecosystems," said Darroch, an assistant professor in Vanderbilt's Earth and Environmental Sciences Department.

"Supporting a simple model would suggest that these mysterious organisms were universally primitive, sharing the same basic ecology and all competing for the same resources," he said. "Support for the complex model would instead suggest that they likely competed for a variety of different resources, just like modern animals. Our analyses support the complex model, illustrating that -- even though they may look bizarre -- these mysterious fossils may have far more in common with modern animals than we thought."

The team first compiled all Ediacaran fossil data from the published literature then added a dataset collected during fieldwork in southern Namibia. These Namibian fossils are the some of the youngest from anywhere in the world and record communities that were living immediately prior to the onset of the Cambrian explosion.

The fossils formed one of the few simple communities in the analysis, suggesting that these organisms were ecologically stressed. That lends support to the idea that the Ediacara biota were gradually going extinct in the run-up to the Cambrian explosion. Although it's an exciting idea, Darroch said, it's only one data point and will need much more research to prove.

The team is also using 3D modeling based on the fossil record to better characterize Ediacara biota, which completely disappeared 540 million years ago -- as early arthropods, mollusks and sponges began to appear.



These are Ediacara biota fossils found during Darroch's latest research in Namibia.




https://www.sciencedaily.com/releases/20...111540.htm



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New dinosaur found in the wrong place, at the wrong time



Researchers have discovered a new dinosaur which roamed the Ningxia Autonomous Region, northwest China, approximately 174 million years ago. This is in a place they were never thought to roam and 15 million years earlier than this type of dinosaur was thought to exist.

A new dinosaur called Lingwulong shenqi or 'amazing dragon from Lingwu' has been discovered by an Anglo-Chinese team involving UCL.

The announcement, published in Nature Communications, reports the surprising discovery of the new dinosaur which roamed the Ningxia Autonomous Region, northwest China, approximately 174 million years ago. This is in a place they were never thought to roam and 15 million years earlier than this type of dinosaur was thought to exist.

Lingwulong is the earliest known example of a type of advanced sauropod dinosaur called a 'neosauropod' -- one of the long-necked, gigantic herbivores that are the largest land animals known, including famous forms such as Brontosaurus and Diplodocus.

Sauropods originated around 200 million years ago, but they only started to truly dominate terrestrial ecosystems by developing gigantic body size (up to 70 metric tonnes) and numerous new adaptations for obtaining and processing plant food.

These giant neosauropod descendants were thought to originate around 160 million years ago, rapidly diversifying and spreading across the world during a time window perhaps as short as just 5 million years.

"We were surprised to find a close relative of Diplodocus in East Asia 174 million years ago. It's commonly thought that sauropods did not disperse there until 200 million years ago and many of their giant descendants, reached this region much later, if at all," explained study co-author Professor Paul Upchurch (UCL Earth Sciences).

"Our discovery of Lingwulong demonstrates that several different types of advanced sauropod must have existed at least 15 million years earlier and spread across the world while the supercontinent Pangaea was still a coherent landmass. This forces a complete re-evaluation of the origins and evolution of these animals."

The new evidence also reinforces the growing realisation that the Early Jurassic (200-175 million years ago), was a key time in dinosaur evolution, witnessing the origins and diversification of many groups that went on to dominate the later Jurassic and Cretaceous.

"Diplodocus-like neosauropods were thought to have never made it to East Asia because this region was cut-off from the rest of the world by Jurassic seaways, so that China evolved its own distinctive and separate dinosaur fauna. However, Lingwulong shows that these Diplodocus-like sauropods were present after all, and implies that the isolation of East Asia was less profound and short-lived than we realised," said lead author, Dr Xing Xu (Institute of Vertebrate Paleontology & Paleoanthropology, Chinese Academy of Sciences, Beijing, China).

For the study, palaeontologists analysed the fossilised skeletons of 7-10 individual dinosaurs that were found together in rocks in 2005 and have been dated at approximately 174 million years old. Funding secured in 2016 by National Geographic Research enabled the formation of this Anglo-Chinese project to study the specimens in detail.

The team conclude that finding such a dinosaur 'in the wrong place, at the wrong time', emphasises the gaps in our knowledge of the fossil record and suggests that there are many surprises still to come.



Artist's impression of dinosaur Lingwulong shenqi.




https://www.sciencedaily.com/releases/20...182438.htm



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Cretaceous Alaska was a 'superhighway' for migrating dinosaurs



Paleontologists have discovered the first North American co-occurrence of hadrosaur and therizinosaur tracks, providing more evidence that Alaska was the ‘superhighway’ for dinosaurs between Asia and western North America 65-70 million years ago (Late Cretaceous epoch).

In 2012-2014, Dr. Anthony Fiorillo from the Perot Museum of Nature and Science and colleagues discovered distinct footprints in Denali National Park, central Alaska Range, that they determined to be made by therizinosaurs, unusual predatory dinosaurs thought to have become herbivores.

What surprised the team most was the co-occurrence of dozens of hadrosaurs, also known as duck-bill dinosaurs.

“Hadrosaurs are very common and found all over Denali National Park. Previously, they had not been found alongside therizinosaurs in the park,” Dr. Fiorillo said.

“In Mongolia, where therizinosaurs are best known — though no footprints have been found in association — skeletons of hadrosaurs and therizinosaurs have been found to co-occur from a single rock unit so this was a highly unusual find in Alaska, and it prompted my interest.”

“From our research, we’ve determined that this track association of therizinosaurs and hadrosaurs is currently the only one of its kind in North America.”

The plant-eating therizinosaurs, which are rare and unusual creatures in the fossil record, had long skinny necks, little teeth, a small beak for cropping plants, and big torsos accompanied by large hind feet and long arms.

Though therizinosaurs are known from Asia and North America, the best and most diverse fossil record is from Asia – even up to the time of extinction – and therein is the connection.

Dr. Fiorillo has long postulated that Cretaceous Alaska could have been the thoroughfare for fauna between Western North America and Asia — two continents that shared each other’s fauna and flora in the latest stages of the Cretaceous.

“This study helps support the idea that Alaska was the gateway for dinosaurs as they migrated between Asia and North America,” said co-author Dr. Yoshitsugu Kobayashi, of Hokkaido University Museum in Japan.

To support the theory, the researchers worked to establish if the tracks were those of a therizinosaur and to study any unique aspects of the ecosystem.

They determined that this particular area of Denali was a wet, marsh-like environment and that one fossil in particular looked like a water lily, which supported the theory that there were ponds and standing water nearby. They suspect that both therizinosaurs and hadrosaurs liked these wetter locations.

“This Alaskan discovery may connect these animals environmentally and perhaps behaviorally to other therizinosaurs in central Asia,” Dr. Fiorillo said.



Life reconstruction of hadrosaur-therizinosaur co-occurrence based on tracks described in this study.




The first North American co-occurrence of hadrosaur and therizinosaur tracks: (a) photo of large block in study area that demonstrates the co-occurrence of both hadrosaurid (in blue) and therizinosaurid (in yellow) tracks on the same bedding plane; (b) line drawing of tracks on the slab in (a), with hadrosaurid tracks in blue, therizinosaurid tracks in yellow; note the different sizes of hadrosaur tracks indicating multiple generations of this type of dinosaur.




http://www.sci-news.com/paleontology/cre...06284.html



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Paleoworld


Season 1, Episode 9 - "Dino Sex"







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An Interactive Map of Every Dinosaur Found on Earth:


Scientists have created a massive database of fossils discovered all around the world in a painstaking project that covers 165 million years of dinosaur evolution.

The Paleobiology Database encompasses all known dinosaur species, with more than 2,000 types represented across every continent on Earth. And, it’s steadily growing, as researchers continue to discover new dinosaurs ‘to the tune of a new species every month or two.’

A remarkable interactive map visualizing the data allows users to explore nearly 8,000 discovery sites, revealing information on what could be as many as 25,000 dinosaur fossils.

Dr Matthew Carrano, Curator of Dinosauria at the Smithsonian Institution, National Museum of Natural History, first began contributing to the database in 2000 – and, the work continues to grow today.

In the map, dots of different colours can be seen scattered around the globe, representing different periods in Earth’s history.

‘You can select “Cretaceous” and the map will show you the continents during the Cretaceous Period and you can see where “today’s” Cretaceous dinosaur fossils would have been when those animals were alive,' Carrano said.

Users can choose to browse based on a particular type of fossil or era, or simply choose a location and zoom in to learn more.

The data, which for now excludes birds, covers the Middle Triassic through the latest Cretaceous periods, about 235 to 66 million years ago.

Many others have joined the effort as well, including UK-based researchers Richard Butler, Roger Benson, and Philip Mannion.

The expansive dataset comes from ‘basically any and all’ scientific publications on dinosaur fossils, Carrano explained, as long as they include enough geologic, geographic, and fossil information to accurately place each discovery.

While it’s ‘extremely comprehensive,’ Carrano says there’s still much work to be done as new discoveries continue to pop up every year. 



A screenshot of the database navigator.




The Paleobiology Database Link:

https://paleobiodb.org/navigator/



https://www.dailymail.co.uk/sciencetech/...Earth.html

[Resurgence]

Early Pioneers in Paleontology:



Anaximander



Ancient Roman mosaic from Johannisstraße, Trier, dating to the early third century AD, showing Anaximander holding a sundial.




Anaximander (c. 610 - c. 546 BC) was a pre-Socratic Greek philosopher who lived in Miletus, a city of Ionia (in modern-day Turkey). He belonged to the Milesian school and learned the teachings of his master Thales. He succeeded Thales and became the second master of that school where he counted Anaximenes and, arguably, Pythagoras amongst his pupils.
 
According to available historical documents, he is the first philosopher known to have written down his studies, although only one fragment of his work remains. Fragmentary testimonies found in documents after his death provide a portrait of the man.

He was an early proponent of science and tried to observe and explain different aspects of the universe, with a particular interest in its origins, claiming that nature is ruled by laws, just like human societies, and anything that disturbs the balance of nature does not last long. Like many thinkers of his time, Anaximander's philosophy included contributions to many disciplines. In astronomy, he attempted to describe the mechanics of celestial bodies in relation to the Earth. In physics, his postulation that the indefinite (or apeiron) was the source of all things led Greek philosophy to a new level of conceptual abstraction. His knowledge of geometry allowed him to introduce the gnomon in Greece. He created a map of the world that contributed greatly to the advancement of geography. He was also involved in the politics of Miletus and was sent as a leader to one of its colonies.

Evolutionary theory begins with Anaximander. Very little is known about his life, but it is known that he wrote a long poem, On Nature, summarizing his researches. This poem is now lost, and has survived only in extracts quoted in other works. Enough survives, however, that Anaximander's thought can be reconstructed with some confidence. For Anaximander, the world had arisen from an undifferentiated, indeterminate substance, the apeiron. The Earth, which had coalesced out of the apeiron, had been covered in water at one stage, with plants and animals arising from mud. Humans were not present at the earliest stages; they arose from fish. This poem was quite influential on later thinkers, including Aristotle.

Had Anaximander looked at fossils? Did he study comparative fish and human anatomy? Unfortunately, we have no way of knowing what evidence Anaximander used to support his ideas. His theory bears some resemblance to evolutionary theory, but also seems to have been derived from various Greek myths, such as the story of Deucalion and Pyrrha, in which peoples or tribes are born from the Earth or from stones. His concept of the apeiron seems similar to the Tao of Chinese philosophy and religion, and to the "formless and void" Earth of the Hebrew creation accounts. However, even though Anaximander's ideas drew on the religious and mythical ideas of his time, he was still one of the first to attempt an explanation of the origin and evolution of the cosmos based on natural laws.



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Oldest frog relative found in North America



Virginia Tech Assistant Professor Michelle Stocker holds a rock with an enbedded Chinle frog hipbone fossil. The size of an eyelash -- look for the small brownish line with a dot at the bottom -- the fossil was found in Arizona.




A team of paleontologists led by Virginia Tech's Michelle Stocker and Sterling Nesbitt of the Department of Geosciences have identified fossil fragments of what are thought to be the oldest known frogs in North America.

The fossils are comprised of several small pieces of hip bone, called an ilium, from Chinle frogs, a distant long-extinct branch of, but not a direct ancestor of, modern frogs. The fragments are packed into rock and are smaller than a pinky nail. They represent the first known and earliest equatorial remains of a salientian -- the group containing living frogs, and their most-closely related fossil relatives -- from the Late Triassic, roughly 216 million years ago.

The name of the fossil derives from where they were found, the Chinle Formation of Arizona.

Stocker, an assistant professor of geosciences in the Virginia Tech College of Science, says the fossils, discovered in May 2018, underscore the importance of microfossil collection and analysis for understanding extinct species whose total length is under three feet in length.

"This new find highlights just how much there is still to learn about the Late Triassic ecosystem, and how much we find when we just look a little closer," Stocker said. "We're familiar with the charismatic archosaurs from the Chinle Formation, but we know that based on other ecosystems, they should make up a small percentage of the animals that lived together. With this new focus we're able to fill in a lot of those missing smaller components with new discoveries."

Coming from multiple individuals, the hip bones are are long and hollow, with a hip socket offset rather than centered. The bones of the frogs show how tiny they were: Just a bit over half-an-inch long.

"The Chinle frog could fit on the end of your finger," Stocker added.

Stocker and her team include researchers from Virginia Tech, Arizona's Petrified Forest National Park, and the University of Florida's Museum of Natural History, with the findings published today in the online journal Biology Letters. Even though the fossils are part of the Chinle frog family, they are not yet naming the specific fossils.

"We refrain from naming this Chinle frog because we are continuing to process microvertebrate matrix that will likely yield additional skull and postcranial material that has the potential to be even more informative," Stocker added.

The Chinle frog shares more features with living frogs and Prosalirus, an Early Jurassic frog found in sediments from the present-day Navajo Nation, than to Triadobatrachus, an Early Triassic frog found in modern day Madagascar in Africa. "These are the oldest frogs from near the equator," Stocker added. "The oldest frogs overall are roughly 250 million years old from Madagascar and Poland, but those specimens are from higher latitudes and not equatorial."

Added Nesbitt, also an assistant professor of geosciences, "Now we know that tiny frogs were present approximately 215 million years ago from North America, we may be able to find other members of the modern vertebrate communities in the Triassic Period." (During the Triassic, the separate continents we recognize today formed the single landmass named Pangaea. Present-day Arizona was located roughly 10 degrees north of the equator.)

The team added this discovery also marks the first time that frog fossils have been found directly with phytosaurs, and other early dinosaurs.

The Virginia Tech team included both undergraduate and graduate students from across the university, using fossils found in the field and dousing additional rock samples repeatedly in water buckets.

Further study of the fossils was completed by CT scans. The undergraduates who accompanied Stocker and Nesbitt on the spring 2018 expedition to Arizona included Elizabeth Evans, a major in the School of Performing Arts; Rebecca Hawkins, majoring in the Department of Fish and Wildlife Conservation; and Hector Lopez, majoring in biological sciences.

"Through my internship with Drs. Stocker and Nesbitt in Arizona, I learned firsthand the hard work that paleontologists put into finding fossils," said Hawkins, a sophomore in the College of Natural Resources and Environment. "Every day you have to brave long treks, heavy loads, scorching heat, and more. But, with just the right combination of patience and luck, you can find something truly amazing that makes the toil worth it, like a tiny frog hip that tells a big story."

"Our development of methods that recover delicate bones from small-bodied vertebrates enabled this exciting discovery," said Ben Kligman, a Ph.D. student in Geosciences from Philadelphia, Pennsylvania. "Our aim is to use similar techniques in the Chinle Formation to uncover the early history of other small-bodied animals including lizards, salamanders, turtles, and mammals."



https://www.sciencedaily.com/releases/20...081545.htm



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Giant animals lived in Amazonian mega-wetland



A land of giants. This is the best definition for Lake Pebas, a mega-wetland that existed in western Amazonia during the Miocene Epoch, which lasted from 23 million to 5.3 million years ago.

The Pebas Formation was the home of the largest caiman and gavialoid crocodilian ever identified, both of which were over ten meters in length, the largest turtle, whose carapace had a diameter of 3.5 meters, and rodents that were as large as present-day buffaloes.

The Pebas Formation was the home of the largest caiman and gavialoid crocodilian ever identified, both of which were over ten meters in length, the largest turtle, whose carapace had a diameter of 3.5 meters, and rodents that were as large as present-day buffaloes.

Remains of the ancient biome are scattered over an area of more than 1 million square meters in what is now Bolivia, Acre State and western Amazonas State in Brazil, Peru, Colombia and Venezuela. The oldest datings in this biome are for fossils found in Venezuela and show that Lake Pebas existed 18 million years ago.

Until recently, scientists believed that the mega-swamp dried up more than 10 million years ago, before the Amazon River reversed course. During most of the Miocene, this river flowed from east to west, opposite to its present direction. The giant animals disappeared when the waters of Pebas receded.

While investigating sediments associated with vertebrate fossils from two paleontological sites on the Acre and Purus Rivers, Marcos César Bissaro Júnior, a biologist affiliated with the University of São Paulo's Ribeirão Preto School of Philosophy, Science and Letters (FFCLRP-USP) in Brazil, obtained datings of 8.5 million years with a margin of error of plus or minus 500,000 years.

There is evidence that the Amazon was already running in its present direction 8.5 million years ago, draining from the Peruvian Andes into the Atlantic Ocean. By then, the Pebas system must have no longer resembled the magnificent wetlands of old. Rather, the system resembled a floodplain similar to the present-day Brazilian Pantanal. This is the view of Annie Schmaltz Hsiou, a professor in the Biology Department at FFCLRP-USP and supervisor of Bissaro Júnior's research, which is described in a recently published article in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.

The study was supported by São Paulo Research Foundation -FAPESP and Brazil's National Council for Scientific and Technological Development (CNPq). The participants also included researchers from the Federal University of Santa Maria (UFSM), the Zoobotanic Foundation's Natural Science Museum in Rio Grande do Sul, São Paulo State University (UNESP), the Federal University of Acre, and Boise State University in Idaho (USA).

The Pebas system encompasses several geological formations in western Amazonia: the Pebas and Fitzcarrald Formations in Peru and Brazil, the Solimões Formation in Brazil, the Urumaco and Socorro Formations in Venezuela, the La Venta Formation in Colombia, and the Quebrada Honda Formation in Bolivia.

"While the Solimões Formation is one of the best-sampled Neogene fossil-bearing stratigraphic units of northern South America, assumptions regarding deposition age in Brazil have been based largely on indirect methods," Bissaro Júnior said.

"The absence of absolute ages hampers more refined interpretations on the paleoenvironments and paleoecology of the faunistic associations found there and does not allow us to answer some key questions, such as whether these beds were deposited after, during or before the formation of the proto-Amazon River."

To answer these and other questions, Bissaro Júnior's study presents the first geochronology of the Solimões Formation, based on mineral zircon specimens collected at two of the region's best-sampled paleontological sites: Niterói on the Acre River in the municipality of Senador Guiomar and Talismã on the Purus River in the municipality of Manuel Urbano.

Since the 1980s, many Miocene fossils have been found at the Niterói site, including crocodilians, fishes, rodents, turtles, birds, and xenarthran mammals (extinct terrestrial sloths). Miocene fossils of crocodilians, snakes, rodents, primates, sloths, and extinct South American ungulates (litopterns) have been found in the same period at the Talismã site.

As a result of the datings, Bissaro Júnior discovered that the rocks at the Niterói and Talismã sites are approximately 8.5 million and 10.9 million years old (maximum depositional age), respectively.

"Based on both faunal dissimilarities and maximum depositional age differences between the two localities, we suggest that Talismã is older than Niterói. However, we stress the need for further zircon dating to test this hypothesis, as well as datings for other localities in the Solimões Formation," he said.

Drying up of Pebas

Lake Pebas was formed when the land rose in the proto-Amazon basin as a result of the Andean uplift, which began accelerating 20 million years ago. At that time, western Amazonia was bathed by the Amazon (which then flowed toward the Caribbean) and the Magdalena in Colombia. The Andes uplift that occurred in what is now Peru and Colombia eventually interrupted the flow of water toward the Pacific, causing water to pool in western Amazonia and giving rise to the mega-wetland.

However, the Andes continued to rise. The continuous uplifting of land in Amazonia had two effects. The proto-Amazon, previously pent up in Lake Pebas, reversed course and became the majestic river we now know. During this process, water gradually drained out of the Pebas mega-swamp.

The swamp became a floodplain full of huge animals, which still existed 8.5 million years ago, according to new datings by Bissaro Júnior. Unstoppable geological forces eventually drained the remains of the temporary lagoons and lakes in western Amazonia. This was the end of Pebas and its fauna.

"The problem with dating Pebas has always been associating datings directly with the vertebrate fauna. There are countless datings of rocks in which invertebrate fossils have been found, but dating rocks with vertebrates in Brazil was one of our goals," Schmaltz Hsiou said.

The new datings, she added, suggest that the Pebas system -- i.e., the vast wetland -- existed between 23 million and 10 million years ago. The Pebas system gave way to the Acre system, an immense floodplain that existed between 10 million and 7 million years ago, where reptiles such as Purussaurus and Mourasuchus still lived.

"The Acre system must have been a similar biome to what was then Venezuela, consisting of lagoons surrounding the delta of a great river, the proto-Orinoco," she said.

Giant rodents

Rodents are a highly diversified group of mammals that inhabit all continents except for Antarctica. Amazonia is home to a large number of rodent species.

"In particular, a rodent group known scientifically as Caviomorpha came to our continent about 41 million years ago from Africa," said Leonardo Kerber, a researcher at UFSM's Quarta Colônia Paleontological Research Support Center (CAPPA) and a coauthor of the article published in Palaeogeography, Palaeoclimatology, Palaeoecology.

"In this period, known as the Eocene Epoch, Africa and South America were already totally separated, with at least 1,000 kilometers between the closest points of the two continents, so there couldn't have been any biogeographical connections enabling terrestrial vertebrates to migrate between the two land masses," Kerber said. "However, the ocean currents drove dispersal by means of natural rafts of tree trunks and branches blown into rivers by storms and swept out to sea. Some of these rafts would have borne away small vertebrates. An event of this kind may have enabled small mammals such as Platyrrhini monkeys, as well as small rodents, to cross the ocean, giving rise to one of the most emblematic groups of South American mammals, the caviomorph rodents."

According to Kerber, the continent's caviomorph rodents have undergone a long period of evolution since their arrival, becoming highly diversified as a result. In Brazil, the group is currently represented by the paca, agouti, guinea pig, porcupine and bristly mouse, as well as by the capybara, the world's largest rodent.

"In Amazonia, above all, we now find a great diversity of bristly mice, porcupines, agoutis and pacas. In the Miocene, however, the Amazonian fauna was very different from what we can observe now," Kerber said.

"In recent years, in addition to reporting the presence of many fossils of species already known to science, some of which had previously been recorded in the Solimões Formation and others that were known from other parts of South America but recorded in Solimões for the first time, we've described three new medium-sized rodent species (Potamarchus adamiae, Pseudopotamarchus villanuevai and Ferigolomys pacarana -- Dinomyidae) that are related to the pacarana (Dinomys branickii)."

Kerber said an article to be published shortly in the Journal of Vertebrate Paleontology will recognize Neoepiblema acreensis, an endemic Brazilian Miocene neoepiblemid rodent that weighed some 120 kg as a valid species.

"The species was described in 1990 but was considered invalid at the end of the decade. These fossil records of both known and new species help us understand how life evolved in the region and how its biodiversity developed and experienced extinctions over millions of years in the past," Kerber said.



https://www.sciencedaily.com/releases/20...145630.htm



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Alligator study reveals insight into dinosaur hearing



An interaural time difference is the difference in time it takes a sound to reach each ear of an animal. Some animals use this difference to determine where a sound is coming from.

Scientists have known that birds are exceptionally good at creating neural maps to chart the location of sounds, and that the strategy differs in mammals. Little was known, however, about how alligators process interaural time difference.

A new study of American alligators found that the reptiles form neural maps of sound in the same way birds do. The research by Catherine Carr, a Distinguished University Professor of Biology at the University of Maryland, and her colleague Lutz Kettler from the Technische Universität München, was published in the Journal of Neuroscience on March 18, 2019.

Most research into how animals analyze interaural time difference has focused on physical features such as skull size and shape, but Carr and Kettler believed it was important to look at evolutionary relationships.

Birds have very small head sizes compared with alligators, but the two groups share a common ancestor -- the archosaur -- which predates dinosaurs. Archosaurs began to emerge around 246 million years ago and split into two lineages; one that led to alligators and one that led to dinosaurs. Although most dinosaurs died out during the mass extinction event 66 million years ago, some survived to evolve into modern birds.

Carr and Kettler's findings indicate that the hearing strategy birds and alligators share may have less to do with head size and more to do with common ancestry.

"Our research strongly suggests that this particular hearing strategy first evolved in their common ancestor," Carr said. "The other option, that they independently evolved the same complex strategy, seems very unlikely."

To study how alligators identify where sound comes from, the researchers anesthetized 40 American Alligators and fitted them with earphones. They played tones for the sleepy reptiles and measured the response of a structure in their brain stems called the nucleus laminaris. This structure is the seat of auditory signal processing. Their results showed that alligators create neural maps very similar to those previously measured in barn owls and chickens. The same maps have not been recorded in the equivalent structure in mammal brains.

"We know so little about dinosaurs," Carr said. "Comparative studies such as this one, which identify common traits extending back through evolutionary time add to our understanding of their biology."



https://www.sciencedaily.com/releases/20...132644.htm



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Tiny beetle trapped in amber might show how landmasses shifted



The fossil beetle, Propiestus archaicus, preserved in amber.




In 2016, Shuhei Yamamoto obtained a penny-sized piece of Burmese amber from Hukawng Valley in northern Myanmar, near China's southern border. He had a hunch that the three-millimeter insect trapped inside the amber could help answer how our world today looks the way it does.

After carefully cutting and polishing the amber, Yamamoto determined that the insect, smaller than the phone-end of an iPhone charger, was a new species to science. The beetle, which lived 99 million years ago, is a relative of insects alive today that live under tree bark, and it's giving scientists hints about how Earth's landmasses were arranged millions of years ago.

"This is a very rare find," Yamamoto said, a Field Museum researcher and lead author of a paper in the Journal of Systematic Palaeontology describing the new species. The fossil beetle is one of the oldest known members of its family -- its name, Propiestus archaicus, refers to the fact that it's an ancient relative of the flat rove beetles in the Piestus genus today of which now dominates South America.

While dinosaurs roamed much of Earth 99 million years ago during the Late Cretaceous era, Propiestus, with its flattened body and short legs, was busy conquering smaller turf underneath the bark of rotting trees. Its long, slender antennae were the clear giveaway to Yamamoto that Propiestus was lived in this environment -- similar to today's flat rove beetles.

"The antennae probably had a highly sensitive ability as a sensory organ," Yamamoto said. Smaller hair-like structures attached perpendicular to the antennae would have increased its ability to feel out its surroundings. "There wouldn't have been a lot of space available in the beetle's habitat, so it was important to be able to detect everything," he explains.

Propiestus is just one of the hundreds of thousands of Burmese amber inclusions -- another word for the objects trapped inside the amber -- that scientists have extensively researched over the last 15 years. Many small insects that lived during the Cretaceous era met their maker at the hands of tree sap that engulfed the bugs and hardened into amber. The bugs trapped inside fossilized and remained frozen for millions of years, unaffected by the passage of time. The hardened amber, covered by soil, decayed leaves, and other organic material, eventually blended in with its surroundings.

Because of this, amber in nature doesn't look like it does in jewelry -- in fact, it doesn't look like anything special at all. The small clumps of unpolished amber look like rocks, meaning only those experienced in amber identification, mostly local miners, are able to find them.

After miners extract the amber, the clumps are either sold into the jewelry trade or to scientists like Yamamoto to study the inclusions. For Yamamoto's piece of amber, he used sandpaper to carefully polish the amber just enough to make Propiestus clearly visible.

"It was very exciting, because the cutting process is very sensitive," Yamamoto said. "If you cut too fast or apply too much pressure, you destroy the inclusion inside very quickly."

Once the amber was polished, the beetle was clearly visible, enabling Yamamoto and his colleagues to study the beetle and determine its closest living relatives. Propiestus's flat rove beetle cousins alive today are found mostly in South America, with the exception of one species in Southern Arizona. Myanmar, where Propiestus was found, is literally on the other side of the globe from these places. But it hasn't always been that way.

Millions of years ago, Myanmar and South America were actually quite close to each other, all fused together as part of the megacontinent Gondwanaland, which formed when the earlier megacontinent Pangea broke apart. Gondwanaland itself eventually broke apart, helping to form the continents we recognize on a map today.

Scientists have a clear sense of which of today's continents and subcontinents would have comprised Gondwanaland and which would have made up its sister continent, Laurasia. However, the detailed timing and pattern of Gondwanaland's split into smaller continents is disputable. Searching for supporting or contrasting evidence means analyzing fossils, some as small as Propiestus, to compare their similarities to other organisms discovered across the globe that might have inhabited the same space long ago.

"Like koalas and kangaroos today, certain animals that we think lived in Gondwanaland are only found in one part of the world. Although Propiestus went extinct long ago, our finding probably shows some amazing connections between Southern Hemisphere and Myanmar," Yamamoto said. "Our finding fits well with the hypothesis that, unlike today, Myanmar was once located in the Southern Hemisphere."

Many inclusions in Burmese amber that have been researched in the last 15 years, including Propiestus, show signs that show traits in common with insects from Gondwanaland. By studying these tiny creatures trapped in amber, we're finding answers to the questions surrounding Earth's structure and the life it supported millions of years ago.

"This fossil helps us understand life in the Mesozoic era," he said. "We need to think about everything from that time, both big and small."



https://www.sciencedaily.com/releases/20...102813.htm



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Paleoworld


Season 1, Episode 10 - "Mistaken Identity"

[Resurgence]

Early Pioneers in Paleontology:


Xenophanes of Colophon


Fictionalized portrait of Xenophanes from a 17th-century engraving.




Xenophanes of Colophon (c. 570 – c. 475 BC) was a Greek philosopher, theologian, poet, and social and religious critic.

He was a native of Colophon, a city in Ionia (now western Turkey). It bears mentioning that he lived just fifty miles north of Miletus, a city famed for the birth of philosophy and home to the first Western philosopher, Thales. 

He lived a life of travel, having left Ionia at the age of 25 and continuing to travel throughout the Greek world for another 67 years.

He is considered one of the most important of the so-called Pre-Socratic philosophers for his development and synthesis of the earlier work of Anaximander and Anaximenes (who followed Thales), but chiefly for his arguments concerning the gods. The prevailing belief of the time was that there were many gods who looked and behaved very much like mortals. Xenophanes claimed that there was only one God, an eternal being, who shared no attributes with human beings.

Being a disciple of Anaximander, he was influenced by that philosopher's notions on early Earth processes and the evolution of life. He developed Anaximander's evolutionary theories further. Xenophanes observed fossil fishes and shells and concluded that the land where they were found had been underwater at some time. He taught that the world formed from the condensation of water and "primordial mud." He was the first person known to have used fossils as evidence for a theory of the history of the Earth. The use of fossils to support his suppositions was an important step in advancing from simply stating an idea to backing it up by physical evidence and observation.



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Paleontologists report world's biggest Tyrannosaurus rex



University of Alberta paleontologists have just reported the world's biggest Tyrannosaurus rex and the largest dinosaur skeleton ever found in Canada. The 13-metre-long T. rex, nicknamed "Scotty," lived in prehistoric Saskatchewan 66 million years ago.

"This is the rex of rexes," said Scott Persons, lead author of the study and postdoctoral researcher in the Department of Biological Sciences. "There is considerable size variability among Tyrannosaurus. Some individuals were lankier than others and some were more robust. Scotty exemplifies the robust. Take careful measurements of its legs, hips, and even shoulder, and Scotty comes out a bit heftier than other T. rex specimens."

Scotty has leg bones suggesting a living weight of more than 8,800 kg, making it bigger than all other carnivorous dinosaurs. The scientific work on Scotty has been a correspondingly massive project.

The skeleton was first discovered in 1991, when paleontologists including T. rex expert and UAlberta professor Phil Currie were called in on the project. But the hard sandstone that encased the bones took more than a decade to remove -- only now have scientists been able to study Scotty fully-assembled and realize how unique a dinosaur it is.

It is not just Scotty's size and weight that set it apart. The Canadian mega rex also lays claim to seniority.

"Scotty is the oldest T. rex known," Persons explains. "By which I mean, it would have had the most candles on its last birthday cake. You can get an idea of how old a dinosaur is by cutting into its bones and studying its growth patterns. Scotty is all old growth."

But age is relative, and T. rexes grew fast and died young. Scotty was estimated to have only been in his early 30s when it died.

"By Tyrannosaurus standards, it had an unusually long life. And it was a violent one," Persons said. "Riddled across the skeleton are pathologies -- spots where scarred bone records large injuries."

Among Scotty's injures are broken ribs, an infected jaw, and what may be a bite from another T. rex on its tail -- battle scars from a long life.

"I think there will always be bigger discoveries to be made," said Persons "But as of right now, this particular Tyrannosaurus is the largest terrestrial predator known to science."

A new exhibit featuring the skeleton of Scotty is set to open at the Royal Saskatchewan Museum in May 2019.



https://www.sciencedaily.com/releases/20...163331.htm



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Fossils found in museum drawer in Kenya belong to gigantic carnivore



Simbakubwa kutokaafrika, a gigantic carnivore known from most of its jaw, portions of its skull, and parts of its skeleton, was a hyaenodont that was larger than a polar bear.



Paleontologists at Ohio University have discovered a new species of meat-eating mammal larger than any big cat stalking the world today. Larger than a polar bear, with a skull as large as that of a rhinoceros and enormous piercing canine teeth, this massive carnivore would have been an intimidating part of the eastern African ecosystems occupied by early apes and monkeys.

In a new study published in the Journal of Vertebrate Paleontology, the researchers name Simbakubwa kutokaafrika, a gigantic carnivore known from most of its jaw, portions of its skull, and parts of its skeleton. The 22-million-year-old fossils were unearthed in Kenya decades ago as researchers canvassed the region searching for evidence of ancient apes. Specimens were placed in a drawer at the National Museums of Kenya and not given a great deal of attention until Ohio University researchers Dr. Nancy Stevens and Dr. Matthew Borths rediscovered them, recognizing their significance.

"Opening a museum drawer, we saw a row of gigantic meat-eating teeth, clearly belonging to a species new to science," says study lead author Borths.

Simbakubwa is Swahili for "big lion" because the animal was likely at the top of the food chain in Africa, as lions are in modern African ecosystems. Yet Simbakubwa was not closely related to big cats or any other mammalian carnivore alive today. Instead, the creature belonged to an extinct group of mammals called hyaenodonts.

Hyaenodonts were the first mammalian carnivores in Africa. For about 45 million years after the extinction of the non-avian dinosaurs, hyaenodonts were the apex predators in Africa. Then, after millions of years of near-isolation, tectonic movements of the Earth's plates connected Africa with the northern continents, allowing floral and faunal exchange between landmasses. Around the time of Simbakubwa, the relatives of cats, hyenas, and dogs began to arrive in Africa from Eurasia.

As the relatives of cats and dogs were going south, the relatives of Simbakubwa were going north. "It's a fascinating time in biological history," Borths says. "Lineages that had never encountered each other begin to appear together in the fossil record."

The species name, kutokaafrika, is Swahili for "coming from Africa" because Simbakubwa is the oldest of the gigantic hyaenodonts, suggesting this lineage of giant carnivores likely originated on the African continent and moved northward to flourish for millions of years.

Ultimately, hyaenodonts worldwide went extinct. Global ecosystems were changing between 18 and 15 million years ago as grasslands replaced forests and new mammalian lineages diversified. "We don't know exactly what drove hyaenodonts to extinction, but ecosystems were changing quickly as the global climate became drier. The gigantic relatives of Simbakubwa were among the last hyaenodonts on the planet," remarks Borths.

"This is a pivotal fossil, demonstrating the significance of museum collections for understanding evolutionary history," notes Stevens. "Simbakubwa is a window into a bygone era. As ecosystems shifted, a key predator disappeared, heralding Cenozoic faunal transitions that eventually led to the evolution of the modern African fauna."



https://www.sciencedaily.com/releases/20...080758.htm



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Tracking records of the oldest life forms on Earth



Rocks with banded iron formations and biosignatures - 1,900 million years old, Michigan, US (top left), 2,700 million years old, Ontario, Canada (bottom left) and 2,500 million years old, Karijini National Park, Western Australia (right).



Ancient organic matter of biological origin has been tracked in multiple samples of rock spanning over 2,000 million years of Earth's history, according to researchers.

The research, published in two papers -- one in the Journal of the Geological Society and another in Earth and Planetary Science Letters -- solves the longstanding problem of how scientists can track records of life on Earth in highly metamorphosed rocks more than 3,700 million years old, with organic material often turning into the carbon-based mineral graphite.

In the first study, published in Earth and Planetary Science Letters, the team analyzed ten rock samples of banded iron formations (BIF) from Canada, India, China, Finland, USA and Greenland spanning over 2,000 million years of history.

They argue that carbon preserved in graphite-like crystals -'graphitic carbon'- located alongside minerals such as apatite, which our teeth and bones are made of, and carbonate, are the biosignatures of the oldest life forms on Earth.

"Life on Earth is all carbon-based and over time, it decomposes into different substances, such as carbonate, apatite and oil. These become trapped in layers of sedimentary rock and eventually the oil becomes graphite during subsequent metamorphism in the crust," explained Dr Dominic Papineau (UCL Earth Sciences, Center for Planetary Sciences and the London Centre for Nanotechnology).

"Our discovery is important as it is hotly debated whether the association of graphite with apatite is indicative of a biological origin of the carbon found in ancient rocks. We now have multiple strands of evidence that these mineral associations are biological in banded iron formations. This has huge implications for how we determine the origin of carbon in samples of extra-terrestrial rocks returned from elsewhere in the Solar System."

The team investigated the composition of BIF rocks as they are almost always of Precambrian age (4,600 million years old to 541 million years old) and record information about the oldest environments on Earth.

For this, they analyzed the composition of rocks ranging from 1,800 million years old to more than 3,800 million years old using a range of methods involving photons, electrons, and ions to characterize the composition of graphite and other minerals of potential biogenic origin.

"Previously, it was assumed that finding apatite and graphite together in ancient rocks was a rare occurrence but this study shows that it is commonplace in BIF across a range of rock metamorphic grades," said team member Dr Matthew Dodd (UCL Earth Sciences and the London Centre for Nanotechnology).

The apatite and graphite minerals are thought to have two possible origins: mineralized products of decayed biological organic matter, which includes the breakdown of molecules in oil at high temperatures, or formation through non-biological reactions which are relevant to the chemistry of how life arose from non-living matter.

By showing evidence for the widespread occurrence of graphitic carbon in apatite and carbonate in BIF along with its carbon-isotope composition, the researchers conclude that the minerals are most consistent with a biological origin from the remains of Earth's oldest life forms.

To investigate the extent to which high-temperature metamorphism causes a loss in molecular, elemental and isotope signatures from biological matter in rocks, they analyzed the same minerals from a 1,850 million year old BIF rock in Michigan which had metamorphosed in 550 degree Celsius heat.

In this second study, published today in Journal of the Geological Society, the team show that several biosignatures are found in the graphitic carbon and the associated apatite, carbonate and clays.

They used a variety of high-tech instruments to detect traces of key molecules, elements, and carbon isotopes of graphite and combined this with several microscopy techniques to study tiny objects trapped in rocks which are invisible to the naked eye.

Together, all of their observations of the composition are consistent with an origin from decayed biomass, such as that of ancient animal fossils in museums, but which has been strongly altered by high temperatures.

"Our new data provide additional lines of evidence that graphite associated with apatite in BIF is most likely biological in origin. Moreover, by taking a range of observations from throughout the geological record, we resolve a long-standing controversy regarding the origin of isotopically light graphitic carbon with apatite in the oldest BIF," said Dr Papineau.

"We've shown that biosignatures exist in highly metamorphosed iron formations from Greenland and northeastern Canada which are more than 3,850 million years old and date from the beginning of the sedimentary rock record."



https://www.sciencedaily.com/releases/20...214853.htm



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Mystery shrouding oldest animal fossils solved



Scientists from The Australian National University have discovered the have discovered that 558 million-year-old Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially had mouths and guts.



Scientists from The Australian National University (ANU) have discovered that 558 million-year-old Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially had mouths and guts.

ANU PhD scholar Ilya Bobrovskiy, lead author of the study, said the study shows that simple physical properties of sediments can explain Dickinsonia's preservation, and implies that what can be seen today may not be what these creatures actually looked like.

"These soft-bodied creatures that lived 558 million years ago on the seafloor could, in principle, have had mouths and guts -- organs that many paleontologists argue emerged during the Cambrian period tens of millions of years later," said Mr Bobrovskiy from the ANU Research School of Earth Sciences.

"Our discovery about Dickinsonia -- and many other Ediacaran fossils -- opens up new possibilities as to what they actually looked like."

Ediacara biota were strange creatures that lived on the seafloor 571 to 541 million years ago. They grew up to two meters long and include the earliest known animals as well as colonies of bacteria.

The fact that Dickinsonia and other Ediacara biota fossils were preserved at all in the geological record has been a big mystery -- until now.

The team, which includes scientists from Russian institutions, discovered how Ediacara biota fossils were preserved, despite the macroorganisms not having skeletons or shells.

"As the organisms decayed, softer sediment from below gradually flowed into the forming void, creating a cast," Mr Bobrovskiy said.

"Now we know that what we are looking at is an impression of a soft organic skeleton that may have been anywhere within Dickinsonia's body. What we're seeing could be a part of Dickinsonia's bottom, the inside of its body or part of its back."

Mr Bobrovskiy said Dickinsonia had different types of tissues and must have been a true animal.

Co-researcher and RSES colleague Associate Professor Jochen Brocks said the team used a melting cast made of ice to show the physical properties of sediments that enabled the soft-bodied Ediacara biota to be preserved.

"This process of fossilization could tell us more about what Ediacara biota were and how they lived," he said.



https://www.sciencedaily.com/releases/20...130441.htm



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Paleoworld


Season 1, Episode 11 - "The Legendary T-rex"

[Resurgence]

Early Pioneers in Paleontology:


Herodotus


A Roman copy (2nd century AD) of a Greek bust of Herodotus from the first half of the 4th century BC.



Herodotus (c. 484 BC – c. 425 BC) was a Greek historian who was born in Halicarnassus in the Persian Empire (modern-day Bodrum, Turkey).

He observed fossil shells in Egypt, and cited them as evidence that Egypt had once been underwater. He also described a valley in Arabia, in the Mokattam mountains, where he saw "the backbones and ribs of such serpents as it is impossible to describe: of the ribs there were a multitude of heaps. . . " He ascribed these bones to winged serpents that had been killed by ibises. We now know that these are the bones of fossil mammals that wash out of the rocks every rainy season.

He is known for having written the book The Histories, a detailed record of his inquiry on the origins of the Greco-Persian Wars. He is widely considered to have been the first writer to have treated historical subjects using a method of systematic investigation—specifically, by collecting his materials and then critically arranging them into an historiographic narrative. On account of this, he is often referred to as "The Father of History", a title first conferred on him by the first-century BC Roman orator Cicero.



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Lecture:


“Exceptionally Preserved Fossils: Windows on the Evolution of Life”


A lecture presented by Paleontologist David Siveter of the University of Leicester.

It was delivered at the Geological Society of London March 27, 2013.






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Documentary:


Dinosaur 13 (2014)






When Paleontologist Peter Larson and his team from the Black Hills Institute of Geological Research made the world's greatest dinosaur discovery in 1990, they knew it was the find of a lifetime; the largest, most complete T. rex ever found. But during a ten-year battle with the U.S. government, powerful museums, Native American tribes, and competing paleontologists, they found themselves not only fighting to keep their dinosaur but fighting for their freedom as well.


The documentary is not available on YouTube so I can’t post it here, but fortunately it is available on The Pirate Bay.


The Pirate Bay Links:


1080p - WEB-DL.DD5.1.H264-RARBG - 2.92 GiB

https://thepiratebay.org/torrent/1094094...H264-RARBG


720p - WEBrip XviD AC3 MiLLENiUM - 1.35 GiB

https://thepiratebay.org/torrent/1136111..._MiLLENiUM



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How evolution brought a flightless bird back from extinction - a modern example of iterative evolution







Around 136,000 years ago, the Aldabra atoll in the Indian Ocean was inundated by a major flood that wiped out all the terrestrial animals that lived there—among them a species of flightless bird called the Aldabra rail. Tens of thousands of years later, sea levels fell back, once again making life possible on the atoll. And, according to a new study, the once-extinct Aldabra rail came back.

Writing in the Zoological Journal of the Linnean Society, Julian Hume of the Natural History Museum at Tring in the U.K. and David Martill of the University of Portsmouth explain that this feat of resurrection was made possible by “iterative evolution”—a rare process that involves the evolution of “similar or parallel structures” from the same ancestral lineage, but at different times.

The Aldabra rail is a subspecies of the white-throated rail (Dryolimnas cuvieri), which is indigenous to islands in the southwestern Indian Ocean. The birds are “persistent colonizers,” according to the University of Portsmouth; they are known to build up on large land bodies and subsequently depart en masse, possibly triggered by overcrowding and a lack of food.

“Something sets them off and they fly in all directions,” Hume tells Josh Davis of the Natural History Museum. “It can happen every fifty years or every hundred years. People still don't really understand it, but if the birds are lucky some of them will land on an island.”

At some point in the distant past, rails landed on Aldabra. There were no predators on the atoll, rendering the birds’ ability to fly unnecessary—so they lost it. And in the wake of the inundation event, the process happened again: Rails arrived on Aldabra and, faced with a lack of predation, once again lost their flight.

“In 20,000 years or less, the rails were evolving flightlessness again,” Hume states. “Evolution can be incredibly quick if the conditions are right.”

The researchers were able to piece together this evolutionary puzzle by studying fossil evidence from before and after the atoll was flooded. More specifically, two humeri dating to at least 136,000 years ago were compared to another rail leg bone found in a deposit that is around 100,000 years old. The researchers also looked at modern rail specimens—some originating from birds that could fly, and some from Aldabran birds that could not.

They found that the pre-flood specimens are very similar to the bones of the flightless rails that exist on Aldabra today. And the leg bone belonging to a rail that lived on Aldabra in the immediate post-flood period suggests that the bird was in the process of losing its flight—or, in other words, that virtually the same subspecies was evolving on Aldabra for the second time.

“From that one bone we can see that it is already becoming more robust when compared to the flying rail, showing that the bird is getting heavier and so losing its ability to fly,” Hume says.

The study authors say their findings offer “irrefutable evidence that Dryolimnas subsequently recolonized Aldabra after inundation and became flightless for a second time.” It is very rare to find such patent signs of iterative evolution in the avian fossil record, and unheard of for the rail family, according to the researchers.

The Aldabra rail is, in fact, the only flightless rail that still survives in the Indian Ocean. But the new study shows how quickly evolution works to favor flightlessness in this bird species—provided that conditions are right.



https://www.smithsonianmag.com/smart-new...180972166/



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Scientists identify blue hues in fossilized bird feathers for the first time







Artist's rendering of the extinct Eocoracias brachyptera bird (Marta Zaher/University of Bristol).




A prehistoric Eocoracias brachyptera bird whose fossilized remains were recovered from Germany’s Messel Pit some 48 million years after its demise boasts the oldest evidence of blue plumage identified to date, according to a new study in Journal of the Royal Society Interface.

Researchers led by Frane Babarović, a Ph.D. student at England’s University of Sheffield, report that blue-hued feathers—now reconstructed from the fossil record for the very first time—can be differentiated from iridescent, brown, black and reddish-brown shades by taking a closer look at tiny pigment sacs called melanosomes.



Different melanosome structures are associated with different colors.




“We have discovered that melanosomes in blue feathers have a distinct range in size from most … colour categories and we can, therefore, constrain which fossils may have been blue originally,” Babarović says in a press release. “The overlap with grey colour may suggest some common mechanism in how melanosomes are involved in making grey colouration and how these structural blue colours are formed.”

Blue as a color is both harder to achieve and to discern. According to Earth.com’s Kay Vandette, blue birds’ feathers contain blue light-scattering cavities. It is impossible, therefore, to determine whether a bird boasted blue plumage without studying the dark melanin pigments responsible for absorbing the remaining unscattered light.

Although blue, green and color-shifting iridescent feathers—as seen in peacocks and hummingbirds—share a specific structure consisting of a layer of spongy keratin and another of pigment-carrying melanosomes, Science News’ Carolyn Gramling points out that these so-called structural colors can be further broken down into iridescent and non-iridescent groups.

Blue, which is non-iridescent, actually has three separate layers: an outer keratin covering, a spongy middle section and an interior layer of melanosomes, as National Geographic's Greshko notes. Whereas iridescent feathers reflect different colors at different angles, non-iridescent ones rely on their multi-layered structure to create a consistent color experience.

“The top layer is structured in such a way that it refracts light in blue wavelength,” Babarović tells Gramling. The melanosomes beneath this layer, meanwhile, absorb the remaining light, keeping the feathers from appearing iridescent.

Keratin doesn’t fossilize well, but melanosomes often do. In fact, National Geographic’s Greshko writes, fossilized pigment sacs have already been recovered from an array of prehistoric creatures, including non-avian dinosaurs, marine reptiles and various bird species.

By drawing on this abundant data source, Babarović and his colleagues set out to discover whether a specific melanosome shape could be associated with non-iridescent blue. Their findings, potentially indicative of an evolutionary link between gray and blue, make it more difficult to determine whether an ancient specimen was one color versus the other, actually lowering the accuracy of previous predictive models of fossil color from 82 percent to 61.9 percent.

Still, Science News’ Gramling notes, this uncertainty can be mitigated by looking toward extinct animals’ modern-day relatives. In the case of E. brachyptera specifically, contemporary counterparts including the Old World family of rollers, kingfishers and kookaburras all have blue feathers, making it extremely likely that their ancient ancestor had a deep blue hue, too.

Moving forward, the researchers hope to gain a better understanding of why blue emerged as an evolutionary option and exactly what role it plays in avian creatures’ livelihood.

“It’s something that hasn’t been explored as much,” Klara Norden, an evolutionary biologist at Princeton University who was not involved in the study, concludes to Gramling. “No one’s really looked at non-iridescent structural colors before at a large scale, because we’ve never had this dataset before. It’s really exciting to have this study out there that shows the shape of these melanosomes.”



https://www.smithsonianmag.com/smart-new...180972510/



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Feathers arose 80 million years before birds



Reconstruction of Kulindadromeus zabaikalicus.




According to a new review paper published in the journal Trends in Ecology & Evolution, feathers arose 250-230 million years ago, during the Early Triassic, when life was recovering from the devastating end-Permian mass extinction.

It is shocking to realize that feathers originated long before birds because feathers have generally been regarded as the key innovation that drove the success of the avian fauna.

However, thousands of fossils from China have shown that many non-avian dinosaurs also had feathers, including feather types not found in birds today.

Those discoveries extended the origin of feathers minimally back to 175 million years ago — about 25 million years before the first generally acknowledged bird, Archaeopteryx.

Recent discoveries of feathers in ornithischian dinosaurs hinted that they are a character of dinosaurs as a whole.

Another startling discovery showed that even pterosaurs had four kinds of feather, apparently similar in form with those of dinosaurs, their closest relatives.

“The oldest bird is still Archaeopteryx first found in the Late Jurassic of southern Germany in 1861, although some species from China are a little older,” said University of Bristol’s Professor Mike Benton, lead author of the paper.

“Those fossils all show a diversity of feathers: down feathers over the body and long, vaned feathers on the wings. But, since 1994, paleontologists have been contending with the perturbing discovery, based on hundreds of amazing specimens from China, that many dinosaurs also had feathers.”

“At first, the dinosaurs with feathers were close to the origin of birds in the evolutionary tree,” added co-author Dr. Baoyu Jiang, a researcher at the University of Nanjing.

“This was not so hard to believe. So, the origin of feathers was pushed back at least to the origin of those bird-like dinosaurs, maybe 200 million years ago.”

“Then, we had the good fortune to work on Kulindadromeus zabaikalicus, a feathered plant-eating dinosaur that lived in the lake-dotted lowlands of Jurassic Siberia between 169 and 144 million years ago,” said co-author Dr. Maria McNamara, from University College Cork.

“This dinosaur showed amazingly well-preserved skin covered with scales on the legs and tail, and strange whiskery feathers all over its body.”

“What surprised people was that this was a dinosaur that was as far from birds in the evolutionary tree as could be imagined. Perhaps feathers were present in the very first dinosaurs.”

“Modern birds like chickens often have scales on their legs or necks, and we showed these were reversals: what had once been feathers had reversed to be scales,” said co-author Dr. Danielle Dhouailly, from the University of Grenoble.

“In fact, we have shown that the same genome regulatory network drives the development of reptile scales, bird feathers, and mammal hairs. Feathers could have evolved very early.”

“The breakthrough came when we were studying two new pterosaurs from China. We saw that many of their whiskers were branched. We expected single strands — monofilaments — but what we saw were tufts and down feathers. Pterosaurs had feathers,” Dr. Jiang said.

“This drives the origin of feathers back to 250 million years ago at least,” Professor Benton said.

“The point of origin of pterosaurs, dinosaurs and their relatives. The Early Triassic world then was recovering from the most devastating mass extinction ever, and life on land had come back from near-total wipe-out.”

“Paleontologists had already noted that the new reptiles walked upright instead of sprawling, that their bone structure suggested fast growth and maybe even warm-bloodedness, and the mammal ancestors probably had hair by then.”

“So, the dinosaurs, pterosaurs and their ancestors had feathers too. Feathers then probably arose to aid this speeding up of physiology and ecology, purely for insulation. The other functions of feathers, for display and of course for flight, came much later.”



http://www.sci-news.com/biology/feathers...07256.html



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Giant birds roamed Europe two million years ago



Pachystruthio dmanisensis.




A giant ostrich-like bird that lived about two million years ago (Pleistocene epoch) has been identified from a fossilized femur found in the Crimean Peninsula, Ukraine.

Named Pachystruthio dmanisensis, the ancient bird was at least 11.5 feet (3.5 m) tall and had an estimated body mass of about 450 kg.

These values make it one of the largest known birds — comparable to the elephant bird Aepyornis maximus — and the only bird of such giant size in Europe and the Northern Hemisphere in general.

In contrast to very large birds from Madagascar, New Zealand and Australia, Pachystruthio dmanisensis was a good runner, which may be explained by its co-existence with large carnivorous mammals.

“Its femur is comparable to modern ostriches as well as smaller species of moa and terror birds. Speed may have been essential to the bird’s survival,” said Dr. Nikita Zelenkov from the Borissiak Paleontological Institute and colleagues.

“Alongside its bones, we found fossils of highly-specialized, massive carnivores from the Ice Age. They included giant cheetah, giant hyenas and saber-toothed cats, which were able to prey on mammoths.”

The nearly complete left femur of Pachystruthio dmanisensis came from the recently-discovered Taurida karst cave in the Belogorsk region, the Crimean Peninsula.

“When I first felt the weight of the bird whose thigh bone I was holding in my hand, I thought it must be a Malagasy elephant bird fossil because no birds of this size have ever been reported from Europe. However, the structure of the bone unexpectedly told a different story,” Dr. Zelenkov said.

“We don’t have enough data yet to say whether it was most closely related to ostriches or to other birds, but we estimate it weighed about 450 kg. This formidable weight is nearly double the largest moa, three times the largest living bird, the common ostrich, and nearly as much as an adult polar bear.”

The paleontologists also found the remains of Pachystruthio dmanisensis and a similar range of fossil mammals at the site of Dmanisi in Georgia.

“We suggest that this giant bird reached the northern Black Sea region via the southern Caucasus and Anatolia, because the older (Pliocene) finds of this fauna are known from Georgia and Turkey.”



http://www.sci-news.com/paleontology/gia...07334.html



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Paleoworld


Season 1, Episode 12 - “Dino Docs”

[Resurgence]

Early Pioneers in Paleontology:


Empedocles of Akragas


Empedocles, as represented in this 17th-century engraving.




Empedocles (c. 494 – c. 434 BC) was a Greek pre-Socratic philosopher and a citizen of Akragas, a Greek city in Sicily. He postulated that the universe was composed of four basic elements -- earth, air, fire, and water. These elements were stirred by two fundamental forces, which Empedocles called Love and Strife. ("Attraction" and "repulsion" might be better modern terms for what Empedocles actually meant.) The constant interplay of these elements, alternately attracting and repelling each other, had formed the universe. Empedocles claimed that the Earth had given birth to living creatures, but that the first creatures had been disembodied organs. These organs finally joined into whole organisms, through the force of Love, but some of these organisms, being monstrous and unfit for life, had died out.

The theory seems a bit bizarre today, but Empedocles had come up with a sort of evolutionary theory: past natural selection is responsible for the forms we see today. Empedocles also ascribed the origin of the life of today to the interplay of impersonal forces, in which chance, not the gods, played the major role. There are, however, major differences between Empedocles's ideas and natural selection in the modern sense: Empedocles conceived of his "natural selection" as a past event, not as an ongoing process. Once again, we do not know whether Empedocles had actually found supporting evidence for his theories. He may have been influenced by existing accounts of mythological creatures that seemed to be "put together" out of the parts of different animals, such as centaurs, sphinxes, and chimeras. But perhaps he had also seen deformed animals, or examined "monstrous-looking" fossil bones.

Influenced by Pythagoras ((c. 570 - c. 495 BC) and the Pythagoreans, Empedocles challenged the practice of animal sacrifice and killing animals for food. He developed a distinctive doctrine of reincarnation. He is generally considered the last Greek philosopher to have recorded his ideas in verse. Some of his work survives, more than is the case for any other pre-Socratic philosopher. Empedocles' death was mythologized by ancient writers, and has been the subject of a number of literary treatments.



Honorable Mention:


Hippocrates


A conventionalized image in a Roman "portrait" bust (19th-century engraving).




Hippocrates of Kos (c. 460 – c. 370 BC) is considered one of the most outstanding figures in the history of medicine. He is often referred to as the "Father of Medicine" in recognition of his lasting contributions to the field as the founder of the Hippocratic School of Medicine. This intellectual school revolutionized medicine in ancient Greece, establishing it as a discipline distinct from other fields with which it had traditionally been associated (theurgy and philosophy), thus establishing medicine as a profession.

He is credited with coining the Hippocratic Oath, which is still relevant and in use today. He is also credited with greatly advancing the systematic study of clinical medicine, summing up the medical knowledge of previous schools, and prescribing practices for physicians through the Hippocratic Corpus and other works.

He is known to have collected fossils; in fact, modern excavations at Askleipion, the famous medical school of Hippocrates's day, unearthed a fragment of a fossil elephant molar.



The Askeipion of Kos.




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Documentary:


Lithuanian Amber - Handfuls of Sunlight







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Foot of Cretacious Enantiornithine bird found encased in Burmese amber



The ancient bird, named Elektorornis chenguangi, lived 99 million years ago (Cretaceous period) and had a hyper-elongated third toe.



An artist’s reconstruction of Elektorornis chenguangi, showing the possible probing function of the elongate toe.



Elektorornis chenguangi belongs to a group of extinct birds called Enantiornithes, the most abundant type of bird known from the Mesozoic era.

The bird was smaller than a sparrow, and it was arboreal, meaning it spent most of its time in trees as opposed to on the ground or in water.

“I was very surprised when I saw the amber,” said Dr. Lida Xing, a paleontologist at the China University of Geosciences.

“It shows that ancient birds were way more diverse than we thought. They had evolved many different features to adapt to their environments.”

The fossil that Dr. Xing and colleagues examined is an incomplete right hindlimb with feathers preserved encased in amber, measuring 3.48 x 3.44 x 0.82 cm and weighing 5.51 g. It was found in 2014 at the Angbamo locality in the Hukawng Valley of Myanmar.

The researchers scanned the specimen with micro-CT and created a 3D reconstruction of the foot.

They found that the bird’s third toe, measuring 9.8 mm, is 41% longer than its second toe and 20% longer than its tarsometatarsus (a bone in the lower legs of birds).

They also compared the ratios with those of 20 other extinct birds from the same era and 62 living birds. No bird has a foot that resembles this one.



The foot of Elektorornis chenguangi, with inset providing greater detail on foot, arrowheads marking different apices of unguals and ungual sheathes where visible, and red arrow marking base of metatarsal III. Scale bar – 5 mm (1 mm in inset).




“Elongated toes are something you commonly see in arboreal animals because they need to be able to grip these branches and wrap their toes around them,” said Dr. Jingmai O’Connor, a scientist in the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.

“But this extreme difference in toe lengths, as far as we know, has never been seen before.”

It remains unknown why Elektorornis chenguangi evolved such an unusual feature.

The only known animal with disproportionally long digits is the aye-aye (Daubentonia madagascariensis), a lemur that uses its long middle fingers to fish larvae and insects out of tree trunks for food.

Elektorornis chenguangi might have used its toe for the same purpose.

“This is the best guess we have. There is no bird with a similar morphology that could be considered a modern analog for this fossil bird,” Dr. O’Connor said.

“A lot of ancient birds were probably doing completely different things than living birds. This fossil exposes a different ecological niche that these early birds were experimenting as they evolved.”



http://www.sci-news.com/paleontology/ele...07392.html



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When the dinosaurs died, lichens thrived



When an asteroid smacked into the Earth 66 million years ago, it triggered mass extinctions all over the planet. The most famous victims were the dinosaurs, but early birds, insects, and other life forms took a hit too. The collision caused clouds of ash to block the sun and cool the planet's temperature, devastating plant life. But a new study in Scientific Reports shows that while land plants struggled, some kinds of lichens -- organisms made of fungi and algae living together -- seized the moment and evolved into new forms to take up plants' role in the ecosystem.

You've seen lichens a million times, even if you didn't realize it. "Lichens are everywhere," says Huang. "If you go on a walk in the city, the rough spots or gray spots you see on rocks or walls or trees, those are common crust lichens. On the ground, they sometimes look like chewing gum. And if you go into a more pristine forest, you can find orange, yellow, and vivid violet colors -- lichens are really pretty." They're what scientists call "symbiotic organisms" -- they're made up of two different life forms sharing one body and working together. They're a partnership between a fungus and an organism that can perform photosynthesis, making energy from sunlight -- either a tiny algae plant, or a special kind of blue-green bacterium. Fungi, which include mushrooms and molds, are on their own branch on the tree of life, separate from plants and animals (and actually more closely related to us than to plants). The main role of fungi is to break down decomposing material.

During the mass extinction 66 million years ago, plants suffered since ash from the asteroid blocked out sunlight and lowered temperatures. But the mass extinction seemed to be a good thing for fungi -- they don't rely on sunlight for food and just need lots of dead stuff, and the fossil record shows an increase in fungal spores at this time. Since lichens contain a plant and a fungus, scientists wondered whether they were affected negatively like a plant or positively like a fungus.

"We originally expected lichens to be affected in a negative way, since they contain green things that need light," says Huang.

To see how lichens were affected by the mass extinction, the scientists had to get creative -- there aren't many fossil lichens from that time frame. But while the researchers didn't have lichen fossils, they did have lots of modern lichen DNA.

From observing fungi growing in lab settings, scientists know generally how often genetic mutations show up in fungal DNA -- how frequently a letter in the DNA sequence accidentally gets switched during the DNA copying process. That's called the mutation rate. And if you know the mutation rate, if you compare the DNA sequences of two different species, you can generally extrapolate how long ago they must have had a common ancestor with the same DNA.

The researchers fed DNA sequences of three families of lichens into a software program that compared their DNA and figured out what their family tree must look like, including estimates of how long ago it branched into the groups we see today. They bolstered this information with the few lichen fossils they did have, from 100 and 400 million years ago. And the results pointed to a lichen boom after 66 million years ago, at least for some of the leafier lichen families.

"Some groups don't show a change, so they didn't suffer or benefit from the changes to the environment," says Lumbsch, who in addition to his work on lichens is the Vice President of Science and Education at the Field. "Some lichens went extinct, and the leafy macrolichens filled those niches. I was really happy when I saw that not all the lichens suffered."

The results underline how profoundly the natural world we know today was shaped by this mass extinction. "If you could go back 40 million years, the most prominent groups in vegetation, birds, fungi -- they'd be more similar to what you see now than what you'd see 70 million years ago," says Lumbsch. "Most of what we see around us nowadays in nature originated after the dinosaurs."

And since this study shows how lichens responded to mass extinction 66 million years ago, it could shed light on how species will respond to the mass extinction the planet is currently undergoing. "Before we lose the world's biodiversity, we should document it, because we don't know when we'll need it," says Huang. "Lichens are environmental indicators -- by simply doing a biodiversity study, we can infer air quality and pollution levels."

Beyond the potential implications in understanding environmental impacts and mass extinctions, the researchers point to the ways the study deepens our understanding of the world around us.

"For me, it's fascinating because you would not be able to do this without large molecular datasets. This would have been impossible ten years ago," says Lumbsch. "It's another piece to the puzzle to understanding what's around us in nature."



https://www.sciencedaily.com/releases/20...120432.htm



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World's smallest fossil monkey found in Amazon jungle



A team of Peruvian and American scientists have uncovered the 18-million-year-old remains of the smallest fossil monkey ever found.

A fossilized tooth found in Peru's Amazon jungle has been identified as belonging to a new species of tiny monkey no heavier than a hamster.

The specimen is important because it helps bridge a 15-million-year gap in the fossil record for New World monkeys, says a team led by Duke University and the National University of Piura in Peru.

The new fossil was unearthed from an exposed river bank along the Río Alto Madre de Dios in southeastern Peru. There, researchers dug up chunks of sandstone and gravel, put them in bags, and hauled them away to be soaked in water and then strained through sieves to filter out the fossilized teeth, jaws, and bone fragments buried within.

The team searched through some 2,000 pounds of sediment containing hundreds of fossils of rodents, bats and other animals before they spotted the lone monkey tooth.

"Primate fossils are as rare as hen's teeth," said first author Richard Kay, a professor of evolutionary anthropology at Duke who has been doing paleontological research in South America for nearly four decades.

A single upper molar, the specimen was just "double the size of the head of a pin" and "could fall through a window screen," Kay said.

Paleontologists can tell a lot from monkey teeth, particularly molars. Based on the tooth's relative size and shape, the researchers think the animal likely dined on energy-rich fruits and insects, and weighed in at less than half a pound -- only slightly heavier than a baseball. Some of South America's larger monkeys, such as howlers and muriquis, can grow to 50 times that heft.

"It's by far the smallest fossil monkey that's ever been found worldwide," Kay said. Only one monkey species alive today, the teacup-sized pygmy marmoset, is smaller, "but barely," Kay said.

In a paper published online July 23 in the Journal of Human Evolution, the team dubbed the animal Parvimico materdei, or "tiny monkey from the Mother of God River."

Now stored in the permanent collections of the Institute of Paleontology at Peru's National University of Piura, the find is important because it's one of the few clues scientists have from a key missing chapter in monkey evolution.

Monkeys are thought to have arrived in South America from Africa some 40 million years ago, quickly diversifying into the 150-plus New World species we know today, most of which inhabit the Amazon rainforest. Yet exactly how that process unfolded is a bit of a mystery, in large part because of a gap in the monkey fossil record between 13 and 31 million years ago with only a few fragments.

In that gap lies Parvimico. The new fossil dates back 17 to 19 million years, which puts it "smack dab in the time and place when we would have expected diversification to have occurred in the New World monkeys," Kay said.

The team is currently on another fossil collecting expedition in the Peruvian Amazon that will wrap up in August, concentrating their efforts in remote river sites with 30-million-year-old sediments.



https://www.sciencedaily.com/releases/20...094631.htm



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New evidence of the Sahara's age



The Sahara Desert is vast, generously dusty, and surprisingly shy about its age. New research looking into what appears to be dust that the Sahara blew over to the Canary Islands is providing the first direct evidence from dry land that the age of the Sahara matches that found in deep-sea sediments: at least 4.6 million years old.

"People have been trying to figure it out for several decades," said Daniel Muhs, a geologist with the U.S. Geological Survey in Denver, Colorado. "More recent studies said it was the beginning of the Pleistocene (about 2.6 million years ago). Then others say a few thousand years ago." Added to this is a model suggesting the Sahara Desert first appeared as far back as seven million years ago.

There is also other evidence that the desert has taken breaks and had wetter, greener periods interspersed with arid times. It's this sensitivity to climate -- and the Sahara's role in global climate -- that makes the region so interesting to researchers.

The new work by Muhs and his colleagues in the Canary Islands focused on thick layers of fine reddish-brown soil found among layers of volcanic rocks and dune sands on Fuerteventura and Gran Canaria islands. The islands are off the west coast of North Africa, at the mouth of a spigot that seasonally pours windblown dust off of the Sahara and across the Atlantic Ocean.

Muhs's and his colleagues' mission was to find, identify, and date any layers of ancient African dust in what are called paleosols, or buried, ancient soils. In one coastal location studied, they found layers of dunes made from local shells of sea animals; in another, there were layers of lava from the volcanoes that built the islands. Both of these geologic archives contained paleosols made of very fine-grained minerals rich in quartz and mica -- minerals that do not reflect the local geology of the islands. They do, however, reflect the minerals found on the nearby African mainland.

Luckily for the geologists, the lava flows that sandwich the windblown fine-grained quartz and mica layers made it possible to nail down approximate ages of the Saharan dust. This is because volcanic rocks contain minerals with what are essentially isotopic clocks that start ticking when the minerals in the lava cool and solidify. And since the layers of lava, paleosols, and other local soils are stacked chronologically with the youngest on top, the lava flows provide some boundaries of when the Sahara was dry enough to launch massive dusty storms out over the Atlantic.

In all, the researchers report eight paleosols that record African dust piling up in the Canaries between about 4.8 and 2.8 million years ago, 3.0 to 2.9 million years ago, and at about 400,000 years ago. The oldest paleosols agree with the deep-sea cores, which put the earliest Sahara dust to the Atlantic at about 4.6 million years ago.

That's not to say the Sahara is 4.6-million-years-old. That's only as old as Muhs and his colleagues could determine based on the paleosols and lavas they found.

"We could take it further back in time if we can find the paleosols," Muhs said.



https://www.sciencedaily.com/releases/20...101924.htm



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Paleoworld


Season 1, Episode 13 - "The Mysteries of Extinction"

[Resurgence]

Early Pioneers in Paleontology:



Lucretius







The Roman poet and philosopher Titus Lucretius Carus (99-55 B.C.E.) wrote his long philosophical poem De Rerum Natura ("On the Nature of Things"). In this poem Lucretius proposed, among other things, an "evolutionary" theory similar to that of Empedocles. Here again, species were born out of the Earth, formed by the chance combination of elements. Natural selection led to the extinction of once-living "monstrous" organisms. Those organisms that survived either survived because of their strength, speed, or cunning, or because of their usefulness to people. But Lucretius did not believe in the production of new species from previously existing ones, the "other side of the coin" of true evolutionary theories. He denied that land-dwelling animals could ever have evolved from marine animals. Like Empedocles, he taught that plants and animals had been born from the Earth, and that the formation of new species was finished.

Lucretius challenged the assumption that humans are necessarily superior to animals, noting that mammalian mothers in the wild recognize and nurture their offspring as do human mothers.

Lucretius's poem is an exposition of Epicurean philosophy, and is notable for its insistence on the senses as the only way to obtain knowledge. It is also notable for its long explication of atomism -- the doctrine that everything in the universe is made up of atoms. Lucretius did not originate this theory -- it goes back to the Greek philosopher Democritus of Abdera (fifth century B.C.E) -- but his explanation of it influenced many writers and thinkers of the Middle Ages and Renaissance, despite opposition from the Church.



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Lizard forefoot found preserved in Dominican amber



Light microscopic image of the piece of 15-20-million-year old Dominican amber; the specimen contains a fairy wasp and the left forelimb of an anole lizard; several flow structures can be recognized in the resin.




The left forelimb of an anole lizard (genus Anolis) has been found perfectly preserved in a piece of Miocene-period amber from the Dominican Republic.

“Vertebrate inclusions in amber are very rare, the majority are insect fossils,” said Jonas Barthel, a doctoral student in the Institute for Geosciences at the University of Bonn.

Barthel and colleagues found the left forelimb of the Anolis lizard in a 2-cm piece of 15-20-million-year old Dominican amber.

“The claws and toes are very clearly visible in the honey-brown amber mass, almost as if the tree resin had only recently dripped onto them — yet the tiny foot is about 15 to 20 million years old,” they said.

The researchers examined the specimen by micro-Raman spectroscopy, electron microprobe, and time-of-flight secondary ion mass spectroscopy.

The analyses revealed that the forefoot is broken in two places and that one of the fractures is surrounded by a slight swelling.

“We propose the following model for our observations,” the scientists said.

“While climbing the tree, the lizard got into contact with a flow of resin and could not escape its sticky trap.”

“After some time, it attracted the attention of a predator that ripped off the lizard, leaving solely the fore limb in the resin. Later on, the resin hardened and became deposited within the surrounding soil which represents the starting point of its diagenesis.”

“The presence of ‘Schlauben’ (a succession of flows), the splintered humerus, the edema, the peeled off parts of the skin, and lastly the numerous air bubbles strongly support this model.”

The Raman spectroscopy revealed that mineral hydroxyapatite in the bone had been transformed into fluoroapatite by the penetration of fluorine.

“This is surprising, because we assumed that the surrounding amber largely protects the fossil from environmental influences,” Barthel said.

“However, the small crack may have encouraged chemical transformation by allowing mineral-rich solutions to find their way in.”

The Raman spectroscopy also showed that collagen — the bone’s elastic component — had largely degraded. Despite the seemingly very good state of preservation, there was actually very little left of the original tissue structure.

“We have to expect that at least in amber from the Dominican Republic, macromolecules are no longer detectable,” said Professor Jes Rust, also from the Institute for Geosciences at the University of Bonn.

“It was not possible to detect more complex molecules such as proteins, but the final analyses are still pending.”

“The degradation processes in this amber deposit are therefore very advanced, and there is very little left of the original substance.”



http://www.sci-news.com/paleontology/amb...08174.html



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110-million-year-old fossilized plant gum found



Paleontologists in Brazil have found thin bands of fossil gum — the first occurrence in the fossil record — inside 110-million-year-old (Cretaceous period) fossilized leaves of the extinct plant Welwitschiophyllum brasiliense. The discovery of fossilized plant gum is unusual because of its solubility in water.


Orange-colored gum ducts (arrows) in the brown leaf tissue of Welwitschiophyllum brasiliense from the Crato Formation, Brazil.




A wide variety of plants produce fluid exudates e.g. resins and gums, with each group differing in chemical definitions.

Due to similarity in physical appearance distinguishing exudates based on chemistry is vital, for example gums and resins are visually similar resulting in these terms being used interchangeably.

However, their chemical definitions are very different; resins are composed of lipid-soluble terpenoids, while gums are complex, highly branched (non-starch) water-soluble polysaccharides.

Differences between gum and resin can also be seen in the functional roles within the plant.

The main roles of resins are to respond to wounding, as a defense against pathogens and to dissuade herbivory by insects and other organisms.

Gum is involved in food storage, structural support, and also for wound sealing, but there is no common role across species.

Further confusion arises as some plants, e.g. Boswellia and Commiphora species, even produce exudates with a mixture of polysaccharide and resin components (the gum resins myrrh and frankincense, respectively).

Until now only fossilized plant resin (ambers) and latex filaments have been reported preserved in the fossil record.

While the fossilization of fluid exudates might seem unlikely, the fossilization of resin is relatively common, and extends back some 320 million years to the Carboniferous period, but chemically confirmed gums have never been reported.

“Our discovery overturns the basic assumption that plant gums cannot be preserved in the fossil record,” said lead author Dr. Emily Roberts, a researcher in the School of the Environment, Geography and Geosciences at the University of Portsmouth and the Department of Palaeontology at the University of Vienna.

“It has opened our eyes to the fact that other plant chemicals may also be preserved — we can no longer just make assumptions. When we first tested the gum I was astonished that we were confirming something that was thought to be impossible — it just goes to show that fossil plants can surprise us.”


Fossilized leaves of Welwitschiophyllum brasiliense from the Crato Formation, Brazil.




Using Fourier-transform infrared spectroscopy (FTIR) and attenuated total reflectance (ATR) spectroscopy, Dr. Roberts and colleagues analyzed the amber-colored substance inside Welwitschiophyllum brasiliense leaves from Crato Formation, Brazil.

The chemical spectrum of this substance clearly differed from those of ambers and resins, but resembled spectra of plant gum.

Welwitschiophyllum brasiliense is considered a relative of Welwitschia mirabilis, one of the oldest and most enigmatic plants in existence.

Today, Welwitschia mirabilis can be found only in the Namib Desert in Namibia and Southern Angola and has chemically confirmed gum in both the cone and in abaxial ducts within leaves.

“Our findings confirm that the Welwitschia mirabilis plant found in Africa today produces a gum similar to a plant growing 110 million years ago in Brazil,” said co-author Professor David Martill, also from the School of the Environmental Geography and Geosciences at the University of Portsmouth.

“Welwitschia mirabilis is one of life’s survivors, thriving in one of the harshest environments on earth for over 120 million years.”

“This discovery is extremely exciting, especially when put into the context of these two continents of Africa and South America, being one during the Cretaceous period.”



http://www.sci-news.com/paleontology/fos...08163.html



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Paleontologists find one-billion-year-old green seaweed fossils



Paleontologists have discovered the microscopic fossilized remains of green seaweed near Dalian in the Liaoning province of northern China. The microfossils are approximately one billion years old. They represent a previously unknown species of green seaweed, named Proterocladus antiquus, and are barely visible to the naked eyed at 2 mm in length, or roughly the size of a typical flea.


Proterocladus antiquus.




“These new fossils suggest that green seaweeds were important players in the ocean long before their land-plant descendants moved and took control of dry land,” said senior author Professor Shuhai Xiao, a researcher in the Department of Geosciences and Global Change Center at Virginia Tech.

“The entire biosphere is largely dependent on plants and algae for food and oxygen, yet land plants did not evolve until about 450 million years ago.”

“Our study shows that green seaweeds evolved no later than one billion years ago, pushing back the record of green seaweeds by about 200 million years. What kind of seaweeds supplied food to the marine ecosystem.”

The current hypothesis is that land plants — the trees, grasses, food crops, bushes, even kudzu — evolved from green seaweeds, which were aquatic plants. Through geological time they moved out of the water and became adapted to and prospered on dry land, their new natural environment.

“These fossils are related to the ancestors of all the modern land plants we see today,” Professor Xiao said.

“However, the caveat that not all geobiologists are on the same page — that debate on the origins of green plants remains.”

“Not everyone agrees with us; some scientists think that green plants started in rivers and lakes, and then conquered the ocean and land later.”


In the background of this digital recreation, ancient green seaweed Proterocladus antiquus is seen living in the ocean one billion years ago. In the foreground is the same seaweed in the process of being fossilized far later.




There are three main types of seaweed: brown (Phaeophyceae), green (Chlorophyta), and red (Rhodophyta), and thousands of species of each kind.

Fossils of red seaweed, which are now common on ocean floors, have been dated as far back as 1.047 billion years old.

“There are some modern green seaweeds that look very similar to the fossils that we found,” Professor Xiao said.

“A group of modern green seaweeds, known as siphonocladaleans, are particularly similar in shape and size to the fossils we found.”

Photosynthetic plants are, of course, vital to the ecological balance of the planet because they produce organic carbon and oxygen through photosynthesis, and they provide food and the basis of shelter for untold numbers of mammals, fish, and more.

“Yet, going back 2 billion years, Earth had no green plants at all in oceans,” Professor Xiao said.

“Proterocladus antiquus seaweeds display multiple branches, upright growths, and specialized cells known as akinetes that are very common in this type of fossil,” said lead author Dr. Qing Tang, a postdoctoral researcher in the Department of Geosciences and Global Change Center at Virginia Tech.

“Taken together, these features strongly suggest that the fossil is a green seaweed with complex multicellularity that is circa one billion years old. These likely represent the earliest fossil of green seaweeds. In short, our study tells us that the ubiquitous green plants we see today can be traced back to at least one billion years.”



http://www.sci-news.com/paleontology/pro...08161.html



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Dinosaurs were warm-blooded, study of fossil eggshells suggests



Using a novel technique called clumped isotope paleothermometry, an international team of paleontologists analyzed eggshell fossils representing three major dinosaur groups and found that these creatures were characterized by warm body temperatures.


A nesting cassowary-like dinosaur named Beibeilong sinensis in the act of incubating eggs.




“Dinosaurs sit at an evolutionary point between birds, which are warm-blooded, and reptiles, which are cold-blooded,” said Dr. Robin Dawson, a researcher in the Department of Geology and Geophysics at Yale University.

“Our results suggest that all major groups of dinosaurs had warmer body temperatures than their environment.”

Dr. Dawson and colleagues applied their novel method to the eggshells of three major groups of dinosaurs: Ornithischia, Sauropodomorpha, and Theropoda.

“Clumped isotope paleothermometry is based on the fact that the ordering of oxygen and carbon atoms in a fossil eggshell are determined by temperature,” they explained.

“Once you know the ordering of those atoms, you can calculate the mother dinosaur’s internal body temperature.”

“For example, eggshells of a Troodon, a small, meat-eating theropod, tested at 38 degrees, 27 degrees, and 28 degrees Celsius (or 100.4, 80.6, and 82.4 degrees Fahrenheit).”

“Eggshells from the large, duck-billed dinosaur Maiasaura yielded a temperature of 44 degrees Celsius (111.2 degrees Fahrenheit).”

“Both the Troodon and Maiasaura eggshells were from Alberta, Canada. Meanwhile, fossilized dinosaur eggs from the oospecies — a species classification limited to dinosaur eggs — Megaloolithus, from Romania, tested at 36 degrees Celsius (96.8 degrees Fahrenheit).”


Petrographic microscope images of dinosaur eggshell: (A-C) well-preserved Troodon eggshells from Alberta, Canada; arrows and horizontal lines point to the approximate boundary between the mammillary and prismatic layers; presence of two calcitic layers is diagnostic of non-avian theropods; (D) Maiasaura hadrosaur eggshell from Alberta, Canada, with intermediate preservation; the diagnostic radiating tabular units are indicated by the white arrow; (E) Romanian eggshell (oospecies Megaloolithus cf. M. siruguei) from Tuştea locality, Romania, with intermediate preservation; diagnostic radiating acicular crystals indicated by white arrow; (F) poorly preserved lambeosaurine hadrosaur eggshell fragment from Alberta, Canada. Scale bars – 500 μm.




The scientists conducted the same analysis on cold-blooded invertebrate shells in the same locations as the dinosaur eggshells.

This helped the team determine the temperature of the local environment — and whether dinosaur body temperatures were higher or lower.

“The Troodon samples were as much as 10 degrees Celsius (18 degrees Fahrenheit) warmer than their environment, the Maiasaura samples were 15 degrees Celsius warmer (27 degrees Fahrenheit), and the Megaloolithus samples were 3-6 degrees Celsius (5.4-10.8 degrees Fahrenheit) warmer,” Dr. Dawson said.

“What we found indicates that the ability to metabolically raise their temperatures above the environment was an early, evolved trait for dinosaurs.”



http://www.sci-news.com/paleontology/war...08135.html



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Lecture:


"Almost Like Being There: New Approaches to Deciphering Animal Behaviour from Trace Fossils"


Dr. Jon Noad, Sedimental Services, describes trace fossils left by a wide variety of both invertebrates and vertebrates, from worms to dinosaurs to mammals.


Royal Tyrrell Museum Speaker Series 2017







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Documentary:



Australia's First Four Billion Years








Of all the continents on Earth, none preserves a more spectacular story of our planet's origins than Australia. NOVA's four-part "Australia's First 4 Billion Years" takes viewers on a rollicking adventure from the birth of the Earth to the emergence of the world we know today. With help from host and scientist Richard Smith, we meet titanic dinosaurs and giant kangaroos, sea monsters and prehistoric crustaceans, disappearing mountains and deadly asteroids. Epic in scope, intimate in nature, this is the untold story of the land "down under," the one island continent that has got it all. Join NOVA on the ultimate Outback road trip, an exploration of the history of the planet as seen through the window of the Australian continent.


Produced by PBS in 2013.



Episode 1 - "Awakening"




Episode 2 - "Life Explodes"




Episode 3 - "Monsters"




Episode 4 - "Strange Creatures"





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Paleoworld:


Season 2, Episode 1 - "African Graveyard I: Hunting Dinosaurs"




Season 2, Episode 2 - "African Graveyard II: Discovering Dinos"





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Knowledge Cards:


Weird n' Wild Creatures are a set of knowledge cards originally published by International Masters Publishers, Inc. from 2003 to 2010. The cards contain information on creatures from nature, prehistoric to the present, as well as creatures of the imagination. They are no longer being published.

Monsters of the Past is the first group in the Weird n' Wild Creatures Knowledge Cards set. This group covers animals from the past, mostly dinosaurs, but also mammals, insects and other creatures, as well as some more recently extinct animals.

The cards are very informative and fun to look at.

Now, and in the future, I will post the card's front image first and the back image last.










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Fossil Gallery:


Stingray Fossil Fish

Family Dasayatidae

Green River Formation, Wyoming

The Green River Formation is an Eocene geologic formation (an epoch that lasted from about 56 to 34 million years ago) that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah.







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Paleogeography:


Late Proterozoic - 650 Ma


This map illustrates the break-up of the supercontinent, Rodinia, which formed 1100 million years ago. It is very unlikely that Rodinia was the first supercontinent. However, it was certainly the previous global supercontinent prior to Pangea. Thus the Earth's lithosphere goes through cycles of global supercontinent (and hence low biotic diversity) and multiple Island continents (e.g. today's world).

Rodinia was surrounded by a single ocean, called the Iapetus Ocean or Sea. Towards the end of the Proterozoic, this supercontinent fragmented, giving rise to the late Vendian continents of Pannotia, Siberia, and North China. From Pannotia in turn came the diverse continents of Laurentia, Gondwana,, and Baltica.

The Rodinia supercontinent formed approximately 1 billion years ago due to the subduction of ocean basins followed by a series of continental collisions. The Rodinia supercontinent, situated about the South Pole, is thought to have persisted over 250 million years. Supercontinent rifting and breakup occurred approximately 725 Ma,  producing new ocean basins (e.g. Panthalassic Ocean) and rift faults such as the Reelfoot Rift, which extends from the Gulf of Mexico to Illinios. The active New Madrid earthquake zone in Missouri occurs along the Reelfoot Rift.

[Resurgence]

Early Pioneers in Paleontology:


Shen Kuo








Shen Kuo, born in 1031 in Qiantang, was a Chinese polymathic scientist and statesman of the Song dynasty (960–1279). Excelling in many fields of study and statecraft, he was a mathematician, astronomer, meteorologist, geologist, entomologist, anatomist, climatologist, zoologist, botanist, pharmacologist, medical scientist, agronomist, archaeologist, ethnographer, cartographer, geographer, geophysicist, mineralogist, encyclopedist, military general, diplomat, hydraulic engineer, inventor, economist, academy chancellor, finance minister, governmental state inspector, philosopher, art critic, poet, and musician. He was the head official for the Bureau of Astronomy in the Song court, as well as an Assistant Minister of Imperial Hospitality.

Shen was the first to describe the magnetic needle compass, which would be used for navigation (first described in Europe by Alexander Neckam in 1187). Shen discovered the concept of true north in terms of magnetic declination towards the north pole, with experimentation of suspended magnetic needles and "the improved meridian determined by Shen's [astronomical] measurement of the distance between the pole star and true north". This was the decisive step in human history to make compasses more useful for navigation, and may have been a concept unknown in Europe for another four hundred years (evidence of German sundials made circa 1450 show markings similar to Chinese geomancer compasses in regard to declination).

Alongside his colleague Wei Pu, Shen planned to map the orbital paths of the Moon and the planets in an intensive five-year project involving daily observations, yet this was thwarted by political opponents at court. To aid his work in astronomy, Shen Kuo made improved designs of the armillary sphere, gnomon, sighting tube, and invented a new type of inflow water clock. He was the first literary figure in China to mention the use of the drydock to repair boats suspended out of water, and also wrote of the effectiveness of the relatively new invention of the canal pound lock. Chinese philosopher Mozi (470–391 BC) so far is the first person in history to describe camera obscura (a basic camera). Shen implemented an improved version of the camera, nearly 2000 years later. Shen wrote extensively about movable type printing invented by Bi Sheng (990–1051), and because of his written works the legacy of Bi Sheng and the modern understanding of the earliest movable type has been handed down to later generations. Following an old tradition in China, Shen created a raised-relief map while inspecting borderlands.

Shen Kuo wrote several other books besides the Dream Pool Essays, yet much of the writing in his other books has not survived. Some of Shen's poetry was preserved in posthumous written works. Although much of his focus was on technical and scientific issues, he had an interest in divination and the supernatural, the latter including his vivid description of unidentified flying objects from eyewitness testimony. He also wrote commentary on ancient Daoist and Confucian texts.



In his book Dream Pool Essays, he claimed that the landscape of the world was shaped over millions of years through mountain erosion, uplift, and the deposition of silt. In part, his argument was due to some fossilized seashells found in the Taihang Mountains hundreds of miles from the ocean.

Based on the shells and the erosion of the mountains, he reasoned that the mountain had shifted over thousands of years, coming up with something that wasn’t too far from the modern idea of tectonic shift.

Based on petrified bamboo he found in northern China, he argued that the world had undergone massive climate changes. According to Shen Kuo, the bamboo could only have grown if northern China had once been a far warmer place—again, something we now know to be true.

The Western world wouldn’t really start accepting Shen Kuo’s ideas until the 19th century—nearly 1,000 years later. Shen Kou was a millennium ahead of his time.



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Paleontology News:



The first duckbill dinosaur fossil from Africa hints at how dinosaurs once crossed oceans



The first fossils of a duckbilled dinosaur have been discovered in Africa, suggesting dinosaurs crossed hundreds of kilometres of open water to get there.

The study, published in Cretaceous Research, reports the new dinosaur, Ajnabia odysseus, from rocks in Morocco dating to the end of the Cretaceous, 66 million years ago. Ajnabia was a member of the duckbill dinosaurs, diverse plant-eating dinosaurs that grew up to 15 meters long. But the new dinosaur was tiny compared to its kin -- at just 3 meters long, it was as big as a pony.

Duckbills evolved in North America and eventually spread to South America, Asia, and Europe. Because Africa was an island continent in the Late Cretaceous, isolated by deep seaways, it seemed impossible for duckbills to get there.

The discovery of the new fossil in a mine a few hours from Casablanca was "about the last thing in the world you would expect," said Dr Nicholas Longrich, of the Milner Centre for Evolution at the University of Bath, who led the study. Dr Longrich said: "It was completely out of place, like finding a kangaroo in Scotland. Africa was completely isolated by water -- so how did they get there?"

Study of Ajnabia's distinctive teeth and jawbones show it belonged to Lambeosaurinae, a subfamily of duckbills with elaborate bony head crests. Lambeosaurs evolved in North America before spreading to Asia and Europe, but have never been found in Africa before.

Reconstructing duckbill evolution, they found the lambeosaurs evolved in North America, then spread over a land bridge to Asia. From there, they colonized Europe, and finally Africa.

Because Africa was isolated by deep oceans at the time, duckbills must have crossed hundreds of kilometres of open water- rafting on debris, floating, or swimming -- to colonize the continent. Duckbills were probably powerful swimmers -- they had large tails and powerful legs, and are often found in river deposits and marine rocks, so they may have simply swum the distance.

"Sherlock Holmes said, once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth," said Longrich. "It was impossible to walk to Africa. These dinosaurs evolved long after continental drift split the continents, and we have no evidence of land bridges. The geology tells us Africa was isolated by oceans. If so, the only way to get there is by water."

In reference to this feat, the dinosaur is named "Ajnabia odysseus." Ajnabi being Arabic for "foreigner," and Odysseus referring to the Greek seafarer.

Ocean crossings are rare, improbable events, but have been observed in historic times. In one case, green iguanas traveled between Caribbean islands during a hurricane borne on debris. In another, a tortoise from the Seychelles floated hundreds of kilometres across the Indian Ocean to wash up in Africa.

"Over millions of years," said Longrich, "Once-in-a-century events are likely to happen many times. Ocean crossings are needed to explain how lemurs and hippos got to Madagascar, or how monkeys and rodents crossed from Africa to South America."

But the fact that duckbills and other dinosaur groups spread between continents, even with high sea levels, suggests dinosaurs traveled across oceans as well. "As far as I know, we're the first to suggest ocean crossings for dinosaurs," said Longrich.

Dr Nour-Eddine Jalil, from the Natural History Museum of Sorbonne University (France) said: "The succession of improbable events (crossing an ocean by a dinosaur, fossilization of a terrestrial animal in a marine environment) highlights the rarity of our find and therefore its importance.

"Ajnabia shows us that hadrosaurs have set foot on African land, telling us that ocean barriers are not always an insurmountable obstacle."

https://www.sciencedaily.com/releases/20...083706.htm



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Large tides may have driven evolution of fish towards life on land



Big tidal ranges some 400 million years ago may have initiated the evolution of bony fish and land vertebrates. This theory is now supported by researchers in the UK and at Uppsala University who, for the first time, have used established mathematical models to simulate tides on Earth during this period. The study has been published in Proceedings of the Royal Society A.

"During long periods of the Earth's history, we've had small tidal ranges. But in the Late Silurian and Early Devonian, they seem to have been large in some parts of the world. These results appear highly robust, because even if we changed model variables such as ocean depth, we got the same patterns," says Per Ahlberg, professor of evolutionary organismal biology at Uppsala University.

Between 420 and 380 million years ago (Ma) -- that is, during the end of one geological period, the Silurian, and beginning of the next, the Devonian -- Earth was a completely different world from now. Instead of today's well-known continents there were other land masses, clustered in the Southern Hemisphere. Stretching across the South Pole was the huge continent of Gondwana. North of it was another big one known as Laurussia, and squeezed between the two were a few small continents. Other salient differences compared with now were that Earth's day lasted only 21 hours, since our planet revolved faster on its own axis, and the Moon looked much larger because its orbit was closer to Earth.

Life on land had gradually begun to get established. But the vertebrates, then consisting only of various kinds of fish, were still to be found only in the oceans. Then, during the Devonian, immense diversification of fish took place. One group to emerge was the bony fish, which make up more than 95 per cent of all fish today but were also the ancestors of terrestrial vertebrates. The earliest bony fish were the first animals to evolve lungs. What set off the evolution of bony fish, and how some of them started to adapt to a life on land, has not been clarified. One theory is that it happened in tidal environments where, in some periods, fish had been isolated in pools as a result of particularly large tides. This challenging habitat may have driven the evolution of lungs and, later on, the transformation of fins into front and hind legs.

To test this tidal theory, researchers at Uppsala University, in collaboration with colleagues from the Universities of Oxford and (in Wales) Bangor, used an established mathematical model of the tidal system for the first time to simulate, in detail, the tides in the Late Silurian and Early Devonian. Data on the positions of the continents, the distance of the Moon, the duration of Earth's day, our planet's gravity and the physical properties of seawater were fed into the model. These simulations showed unequivocally that the period, just like that of the present day, was one when large tides occurred in some places. The small continent of South China on the Equator showed a difference of more than four metres in sea level between high and low tide. The existence of tides at the time has previously been verified through studies of geological strata, but determining the extent of the difference between low and high tide has not been feasible. To researchers this news has been interesting, since fossil finds indicate that it was specifically around South China that bony fish originated.

"Our results open the door to further and even more detailed tidal analyses of key episodes in Earth's past. The method can be used to explore the possible role of tides in other evolutionary processes of vertebrate development. And perhaps, conversely, whether tides, with their influence on ocean dynamics, played a part in the big marine extinctions that have taken place again and again in Earth's history," Ahlberg says.

https://www.sciencedaily.com/releases/20...105334.htm



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Antarctica yields oldest fossils of giant birds with 21-foot wingspans



Fossils recovered from Antarctica in the 1980s represent the oldest giant members of an extinct group of birds that patrolled the southern oceans with wingspans of up to 21 feet that would dwarf the 11½-foot wingspan of today's largest bird, the wandering albatross.

Called pelagornithids, the birds filled a niche much like that of today's albatrosses and traveled widely over Earth's oceans for at least 60 million years. Though a much smaller pelagornithid fossil dates from 62 million years ago, one of the newly described fossils -- a 50 million-year-old portion of a bird's foot -- shows that the larger pelagornithids arose just after life rebounded from the mass extinction 65 million years ago, when the relatives of birds, the dinosaurs, went extinct. A second pelagornithid fossil, part of a jaw bone, dates from about 40 million years ago.

"Our fossil discovery, with its estimate of a 5-to-6-meter wingspan -- nearly 20 feet -- shows that birds evolved to a truly gigantic size relatively quickly after the extinction of the dinosaurs and ruled over the oceans for millions of years," said Peter Kloess, a graduate student at the University of California, Berkeley.

The last known pelagornithid is from 2.5 million years ago, a time of changing climate as Earth cooled, and the ice ages began.


Birds with pseudoteeth

Pelagornithids are known as 'bony-toothed' birds because of the bony projections, or struts, on their jaws that resemble sharp-pointed teeth, though they are not true teeth, like those of humans and other mammals. The bony protrusions were covered by a horny material, keratin, which is like our fingernails. Called pseudoteeth, the struts helped the birds snag squid and fish from the sea as they soared for perhaps weeks at a time over much of Earth's oceans.

Large flying animals have periodically appeared on Earth, starting with the pterosaurs that flapped their leathery wings during the dinosaur era and reached wingspans of 33 feet. The pelagornithids came along to claim the wingspan record in the Cenozoic, after the mass extinction, and lived until about 2.5 million years ago. Around that same time, teratorns, now extinct, ruled the skies.

The birds, related to vultures, "evolved wingspans close to what we see in these bony-toothed birds (pelagornithids)," said Poust.

"However, in terms of time, teratorns come in second place with their giant size, having evolved 40 million years after these pelagornithids lived. The extreme, giant size of these extinct birds is unsurpassed in ocean habitats."

The fossils that the paleontologists describe are among many collected in the mid-1980s from Seymour Island, off the northernmost tip of the Antarctic Peninsula, by teams led by UC Riverside paleontologists. These finds were subsequently moved to the UC Museum of Paleontology at UC Berkeley.

Kloess stumbled across the specimens while poking around the collections as a newly arrived graduate student in 2015. He had obtained his master's degree from Cal State-Fullerton with a thesis on coastal marine birds of the Miocene era, between 17 million and 5 million years ago, that was based on specimens he found in museum collections, including those in the UCMP.

"I love going to collections and just finding treasures there," he said. "Somebody has called me a museum rat, and I take that as a badge of honor. I love scurrying around, finding things that people overlook."

Reviewing the original notes by former UC Riverside student Judd Case, now a professor at Eastern Washington University near Spokane, Kloess realized that the fossil foot bone -- a so-called tarsometatarsus -- came from an older geological formation than originally thought. That meant that the fossil was about 50 million years old instead of 40 million years old. It is the largest specimen known for the entire extinct group of pelagornithids.

The other rediscovered fossil, the middle portion of the lower jaw, has parts of its pseudoteeth preserved; they would have been up to 3 cm (1 inch) tall when the bird was alive. The approximately 12-cm (5-inch-) long preserved section of jaw came from a very large skull that would have been up to 60 cm (2 feet) long. Using measurements of the size and spacing of those teeth and analytical comparisons to other fossils of pelagornithids, the authors are able to show that this fragment came from an individual bird as big, if not bigger, than the largest known skeletons of the bony-toothed bird group.


A warm Antarctica was a bird playground

Fifty million years ago, Antarctica had a much warmer climate during the time known as the Eocene and was not the forbidding, icy continent we know today, Stidham noted. Alongside extinct land mammals, like marsupials and distant relatives of sloths and anteaters, a diversity of Antarctic birds occupied the land, sea and air.

The southern oceans were the playground for early penguin species, as well as extinct relatives of living ducks, ostriches, petrels and other bird groups, many of which lived on the islands of the Antarctic Peninsula. The new research documents that these extinct, predatory, large- and giant-sized bony-toothed birds were part of the Antarctic ecosystem for over 10 million years, flying side-by-side over the heads of swimming penguins.

"In a lifestyle likely similar to living albatrosses, the giant extinct pelagornithids, with their very long-pointed wings, would have flown widely over the ancient open seas, which had yet to be dominated by whales and seals, in search of squid, fish and other seafood to catch with their beaks lined with sharp pseudoteeth," said Stidham. "The big ones are nearly twice the size of albatrosses, and these bony-toothed birds would have been formidable predators that evolved to be at the top of their ecosystem."

Museum collections like those in the UCMP, and the people like Kloess, Poust and Stidham to mine them, are key to reconstructing these ancient habitats.



https://www.sciencedaily.com/releases/20...133713.htm



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Cracking the secrets of dinosaur eggshells



Since the famous discovery of dinosaur eggs in the Gobi Desert in the early 1920s, the fossilized remains have captured the imaginations of paleontologists and the public, alike. Although dinosaur eggs have now been found on every continent, it's not always clear to scientists which species laid them. Now, researchers reporting in ACS Omega have narrowed down the list for an unknown eggshell from Mexico by comparing its microstructure and composition with four known samples.

Because many dinosaur eggs are similar in size and shape, it can be difficult to determine what type of dinosaur laid them. Clues can come from fossilized embryos (which are rare), hatchlings in the same nest or nearby adult remains. Scientists also have identified microscopic features of eggshells that differ among groups of dinosaurs. In addition, researchers have studied the elemental composition of fossil eggshells to learn more about the paleoenvironment and conditions that led to the eggs' fossilization. Abel Moreno and colleagues wanted to compare the microstructure and composition of five dinosaur eggshells from nests in the El Gallo Formation of Baja California, Mexico. Based on the eggs' shapes and sizes and the fossil record of the area, the researchers had concluded that three of the eggs were laid by ornithopods (bipedal herbivores) of the hadrosaur family (duck-billed dinosaurs) and one by a theropod (bipedal carnivores) of the troodontidae family (small, bird-like dinosaurs). The remaining sample was too damaged to classify by the naked eye.

Using scanning electron microscopy, the team examined the external and internal surfaces and a cross-section of each eggshell. In contrast to the smooth outer surface of the theropod shell, the shells from the ornithopods and the unknown sample had nodes at different distances across the shell. Images of shell cross-sections from the ornithopods revealed that mammillary cones -- calcite crystals on the inner surface of the shell -- formed thin, elongated columns arranged in parallel, with irregular pores. In contrast, the eggshell from the theropod showed thicker, shorter cones arranged in a bilayer, with wider pores. The unknown sample more closely resembled the ornithopod eggshells, leading the researchers to hypothesize that it was probably also from the hadrosaur family. In addition, the researchers conducted an elemental composition analysis, which they say is the first such analysis on dinosaur eggshells collected in Mexico. They say the findings might help reveal how the fossilization process varied among species and locales.



https://www.sciencedaily.com/releases/20...124515.htm



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New study finds earliest evidence for mammal social behavior



A new study led by paleontologists at the University of Washington and its Burke Museum of Natural History & Culture indicates that the earliest evidence of mammal social behavior goes back to the Age of Dinosaurs.

The evidence, published Nov. 2 in the journal Nature Ecology & Evolution, lies in the fossil record of a new genus of multituberculate -- a small, rodent-like mammal that lived during the Late Cretaceous of the dinosaur era -- called Filikomys primaevus, which translates to "youthful, friendly mouse." The fossils are the most complete mammal fossils ever found from the Mesozoic in North America. They indicate that F. primaevus engaged in multi-generational, group-nesting and burrowing behavior, and possibly lived in colonies. Study co-authors -- including lead author Luke Weaver, a UW graduate student in biology, and senior author Gregory Wilson Mantilla, a UW professor of biology and curator of vertebrate paleontology at the Burke Museum -- analyzed several fossils, all about 75.5 million years old, and extracted from a well-known dinosaur nesting site called Egg Mountain in western Montana.

Fossil skulls and skeletons of at least 22 individuals of F. primaevus were discovered at Egg Mountain, typically clustered together in groups of two to five, with at least 13 individuals found within a 30 square-meter area in the same rock layer. Based on how well preserved the fossils are, the type of rock they're preserved in, and F. primaevus' powerful shoulders and elbows -- which are similar to today's living burrowing animals -- Weaver, Wilson Mantilla and co-authors hypothesize these animals lived in burrows and were nesting together. Furthermore, the animals found were a mixture of multiple mature adults and young adults, suggesting these were truly social groups as opposed to just parents raising their young.

"It was crazy finishing up this paper right as the stay-at-home orders were going into effect -- here we all are trying our best to socially distance and isolate, and I'm writing about how mammals were socially interacting way back when dinosaurs were still roaming the Earth!" said Weaver. "It is really powerful, I think, to see just how deeply rooted social interactions are in mammals. Because humans are such social animals, we tend to think that sociality is somehow unique to us, or at least to our close evolutionary relatives, but now we can see that social behavior goes way further back in the mammalian family tree. Multituberculates are one of the most ancient mammal groups, and they've been extinct for 35 million years, yet in the Late Cretaceous they were apparently interacting in groups similar to what you would see in modern-day ground squirrels."

Previously, scientists thought social behavior in mammals first emerged after the mass extinction that killed off the dinosaurs, and mostly in the Placentalia -- the group of mammals humans belong to, which all carry the fetus in the mother's uterus until a late stage of development. But these fossils show mammals were socializing during the Age of Dinosaurs, and in an entirely different and more ancient group of mammals -- the multituberculates.

"These fossils are game changers," said Wilson Mantilla. "As paleontologists working to reconstruct the biology of mammals from this time period, we're usually stuck staring at individual teeth and maybe a jaw that rolled down a river, but here we have multiple, near complete skulls and skeletons preserved in the exact place where the animals lived. We can now credibly look at how mammals really interacted with dinosaurs and other animals that lived at this time."

https://www.sciencedaily.com/releases/20...120055.htm



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Fossil Discoveries in Ancient Times:


The first dinosaur bones weren’t found by scientists. They were uncovered thousands of years ago by early men with no way of understanding what they were seeing.

Ancient men stumbled upon fossils just like we do today, and they had to do their best to figure out what in the world they were looking at. Some would see femurs the size of a fully grown man or great rib cages that stretched out as wide as a building.

There are a handful of records that give us a hint into how they made sense of these things—small glimpses into what it would have been like to stumble upon the remains of a dinosaur thousands of years ago.



The Battlefield of the Giants

“Before there were any humans,” the Greek historian Solinus wrote 1,800 years ago, “a battle was fought between the gods and the giants.”

To Solinus, this was no myth. He knew for a fact that giants had once roamed the Earth. He’d seen their bones himself.

He was writing about a town called Pallene where Greek mythology tells us that Heracles had destroyed a lawless tribe of giants. Every time it rained, Solinus wrote, massive bones would poke out of the ground “like men’s carcasses but far bigger.”

For much of history, Solinus was written off as a liar. Then, in 1994, a rainstorm hit the place where Pallene had once stood and a villager uncovered what he believed was a giant’s tooth. The ancient town became the site of a paleontological dig. There, we found the remains of ancient mastodons.

The Greeks had only found their remains one bone at a time. With no concept of mastodons, they assumed that they were looking at the remains of massive men. To them, it was concrete proof that they’d built their town on top of a giants’ burial ground.



The Water Monsters Of The Badlands

The Lakota people believed that the Badlands of South Dakota were once the site of an epic battle between water, thunder, and lightning spirits.

The water spirits were giant monsters known as Unktehi that fought a vicious battle against a flock of thunderbirds called Wakinyan that destroyed the whole area. The Wakinyan burned the forests, boiled up the sea, and left nothing but a scorched land behind.

The only thing left, the Lakota believed, were the bones of the dead monsters still lying in the scarred land.

Those bones really are in the South Dakota Badlands. Years later, paleontologists discovered that the area was an incredible source of dinosaur remains. There, they found the bones of marine reptiles called mosasaurs and flying reptiles called pterosaurs, all of which died about 100 million years ago.

It’s believed that the Lakota legend came from them stumbling upon these bones. They found the remains of what really were monsters of the water and the air, living on what had once been an ancient sea.



The Stone Chakras Of Vishnu

A village called Salagrama in Nepal was absolutely overflowing with fossilized seashells. However, the people who found them came to a very different conclusion about what they were looking at. They believed that they’d found the chakras of the four-armed god Vishnu.

In the Hindu belief, Vishnu carried a stone disk called the Sudarshana Chakra in one of his hands. Those seashells, they believed, were Vishnu’s chakra turned to stone by a demon’s curse.

According to an old legend, Vishnu was cursed to turn to stone after disguising himself as the demon Jalandhara to trick Vrinda, Jalandhara’s wife, into sleeping with Vishnu. When Vrinda woke up and realized that the man in her bed wasn’t really her husband, she became so furious that she cursed Vishnu to turn into stone, grass, trees, and plants.

For centuries, ancient Hindus would treat these seashells as sacred objects. They believed that the shells were Vishnu’s chakras that had been turned to stone, broken off, and left on Earth. In other words, they were the holiest things a Hindu could find.



The Fields Of Dragon Bones

Chinese travelers once feared to enter the deserts of Issedonia. They believed that those lands had once been haunted by demons and dragons. The remnants were still there: fields upon fields of white dragon bones.

Issedonia struck a special fear in their hearts, but it wasn’t the only place overrun with dragon bones. The Chinese believed that they were all over the nation. In the I Ching, a farmer uncovering dragon bones in his field is listed as a “good omen.” And in the second century BC, a canal was named the “Dragon-Head Waterway” on the basis that “dragon bones were found” at that site.

Historian Adrienne Mayor believes that those lines stem from farmers digging up the massive bones of extinct animals, and she has a pretty good reason to believe it. As late as 1919, China still had exhibits of dragon bones on display—some of which paleontologists still have today.

However, the bones came from extinct species of horses and deer. They had fossilized into such hard shapes that the ancient people couldn’t imagine that they came from anything less than supernatural monsters.



The Shoulder Blade Of Pelops

An ancient Greek fisherman once cast his net into the sea and found something unexpected. It was a long, thin, white bone, far too large to have come from anything he’d ever seen before.

After a bit of panicking, the fisherman brought the bone to the oracle, who told him that she knew exactly what it was—the shoulder blade of a demigod. She claimed that the bone came from Pelops, son of Tantalus and grandson of Zeus, who supposedly had a shoulder of pure ivory.

According to legend, Pelops had fought and died in the Trojan War. As the Greeks carried his body back home, their ship was hit by a violent storm that knocked Pelops’s body into the water. There, the oracle told the fisherman, the body had lain until he unearthed it.

The bone was put on display at the Temple of Artemis, and the fisherman and his family, who were now seen as blessed by the gods, were appointed as the official caretakers of Pelops. Apparently, they weren’t great at it because the bone had disappeared by AD 150.

We can only speculate about what the fisherman really found. But the leading theory is that he stumbled upon the tusk of a woolly mammoth, perhaps smoothed down from the years underwater until it could pass as the chunk of an ivory shoulder bone.



The Bones Of Antaeus

Two thousand years ago, the people of Tingis insisted that their town had been built next to the burial ground of a massive giant. His name was Antaeus. He had built their city and lived among them for years until he met his end—killed by Heracles in a lethal wrestling match.

To the Romans, this all sounded like a lot of superstitious nonsense. When Roman commander Quintus Sertorius was in Tingis, he resolved to prove the locals wrong. They took him to the supposed giant’s burial mound, which Sertorius’s men dug up. He expected to gloat gleefully when he found nothing there.

However, to Sertorius’s surprise, his men unearthed a gigantic skeleton. It’s unlikely that they dug up much more than a few bones, but they went home insisting that they had discovered the remains of a man who was 26 meters (85 ft) tall.

The humbled Sertorius had the man reburied, conceding that this really was the burial ground of a legendary figure. As a result, we can’t know for sure what he found, but we have a pretty good idea.

Today, that burial mound is a major excavation site for Pliocene-Miocene fossils, where ancient mammoths, whales, and gigantic relatives of the giraffe have been found. One of them probably left the bones that Sertorius dug up.



The Black Bones Of Set

Between 1300 and 1200 BC, the ancient Egyptians uncovered at least 3 tons of fossils. They found the bones of massive, extinct breeds of hippos, crocodiles, boar, horses, antelopes, buffaloes, and more in a huge excavation project.

We can only guess what was going through their minds. Not a single written record of this ancient dig exists today. All we have are the bones and our best guesses.

We know that all the fossils were pitch-black. When the Egyptians found them, they must have thought that the fossils had something to do with the gods. After transporting the bones massive distances, the Egyptians placed them inside shrines to Set, the god of darkness and chaos.

The Egyptians carefully wrapped the fossils in linen and placed them in rock-cut tombs as though giving a respectful burial to the honored dead. Perhaps they thought that these were the remains of gods or some minions of Set. All we know for sure is that they stayed in those tombs wrapped in linen and untouched for more than 3,000 years before they were finally discovered in 1922.



The Mythical Graveyards of the Mahabharata

One of the major Hindu legends is the story of Mahabharata, an epic battle between heroes, gods, and monsters.

There are different versions of the story. But in the wildest ones, it was a single battle fought with millions of soldiers on each side. Hundreds of thousands of elephants, horses, and chariots were brought into the war, leaving thousands of dead bodies rotting on the battlefield when it all ended.

Even the gods joined in. Shiva, Krishna, and Rama all came into the fight, which climaxed in an epic battle between a giant named Bhima and a supernaturally powerful man named Duryodhana. According to the legend, Bhima tore Duryodhana from limb to limb before finally being struck down by a thunderbolt from the sky.

Historian Alexandra van der Geer believes that this story might have had its roots in ancient fossils. The Siwalik Hills, where the legendary battle was fought, is the site of two different types of ancient remains.

First are the giant tortoises, Stegodons, saber-toothed tigers, and four-horned giraffes that died there millions of years ago. By coincidence, it’s also filled with bronze javelins and spears from a real battle that was fought thousands of years ago.

Van der Geer believes that ancient Indians found the remains of old weapons side by side with the bones of unimaginable monsters. The ancients assumed that they’d stumbled upon a mythical battleground, a place where human soldiers had fought alongside monsters.



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Lecture:


"Extinction of Mainland and Island Mammoth Populations in Alaska 6,000 Years"


Dr. Duane Froese, University of Alberta, presents new research on the extinction of mammoths and other megafauna from Arctic North America and the causes of the final extinction of a population on St. Paul Island, Alaska, about 6000 years ago.


Part of the Royal Tyrrell Museum Speaker Series 2017 


Originally published February 21, 2017.






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Documentary:



First Life








David Attenborough investigates the evidence from the earliest fossils, which suggest that complex animals first appeared in the oceans around 540 million years ago, an event known as the Cambrian Explosion. Trace fossils of multicellular organisms from an even earlier period, the Ediacaran biota, are also examined. Attenborough travels to Canada, Morocco and Australia, using some of the latest fossil discoveries and their nearest equivalents amongst living species to reveal what life may have been like at that time. Visual effects and computer animation are used to reconstruct and animate the extinct life forms.


Produced by the BBC in 2010.


Episode 1: "Arrival"





Episode 2: "Conquest"





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Knowledge Cards:


















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Fossil Gallery:



Plant Fossils



Sphenophytes (Horsetails and their extinct relatives)



Fossils of sphenophytes are common plant fossils. Sphenophyte fossils may be found in rocks that were deposited during both the Pennsylvanian and Permian Periods as impressions, compressions, casts and molds.

Sphenophytes include relatives of living horsetails and extinct plant groups that were probably closely related.


Calamites sp. (left) and Sphenophyllum sp. (right) reconstruction.




Calamites

Calamites is a name (= form-genus) for compression/impression and pith casts of arborescent sphenophytes related to modern horsetails. Calamites can be distinguished from a separate form-genus called Archaeocalamites, but technical issues of naming as well as imperfect preservation of fossils makes separating these genera in the field problematic. For convenience, the term Calamites will be used for all stem fossils as well as for the entire plant.

Some Calamites grew to over 60 feet (20 meters) tall and bore leaves in clusters that, found separately, are placed in the form-genera Annularia and Asterophyllites. Calamites and their leaves are commonly found in Carboniferous rocks.

Calamites may be found as cylindrical casts or elongate compressions/impressions. In either form, Calamites may be recognized by grooves/lines running the length of the specimen that are regularly and closely spaced and horizontal grooves or nodes that are widely spaced and might not be regularly spaced.

In some cylindrical casts, small circular bumps appear along the horizontal nodes. If the small bumps are present, the specimen is a cast (sediment infilling) of the pith—the central portion of Calamites inside the wood of the stem. If bumps are not present, the specimen is most likely a cast of the inner surface of the bark outside of the wood of the stem.













Annularia

Annularia is the name (= form-genus) for one type of leaf of Calamites. Annularia is recognized by the cluster of leaves (usually more than 8) that are elongate and narrow, and possess a midvein running the length to or close to the tip. The clusters, called whorls, are only at spaced nodes. The leaves are fused into a ring at their base near the stem. As compressions/impressions, the whole cluster shows a distinct “starburst” appearance—a complete circle of leaves. Annularia is distinguished from Asterophyllites by its starburst circle of leaves in contrast to the upward cup of leaves in Asterophyllites. Annularia is distinguished from Sphenophyllum by its single midvein and non-triangular shape.















Asterophyllites

Asterophyllites is the name (= form-genus) for one type of leaf of Calamites. Asterophyllites is recognized by the cluster of leaves (usually more than 8) that are narrow and possess a midvein running the length to or close to the tip. The clusters, called whorls, occur only at spaced nodes along the stem. As compressions/impressions, the whole cluster is curved upward forming a cup of leaves, each leaf more-or-less pointing toward the top of the stem. Asterophyllites is distinguished from Annularia by its upward cup of leaves in contrast to the starburst circle of leaves in Annularia. Asterophyllites is distinguished from Sphenophyllum by its single midvein and non-triangular leaf shape.















Sphenophyllum

Sphenophyllum is the name (= form-genus) for compression/impression remains of leaves of an enigmatic sphenophyte. Sphenophyllum historically has been allied with horsetails by their similar morphology (leaves in circlets, called whorls, positioned at nodes along the stem) but this relationship is hardly definite. Sphenophyllum is recognized by a circle of triangular leaves, usually 8 or fewer around a node, with 1 or 2 veins entering the base of the leaf and dividing repeatedly from base to tip. The tips of Sphenophyllum leaves may be smooth, jagged (toothed) or forked. Sphenophyllum may be distinguished from both Annularia and Asterophyllites by the triangular leaf shape in contrast with their narrow elongate leaves, and by the many branching veins in contrast to their single midvein.















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Paleogeography:


Animals with hard-shells appeared in great numbers for the first time during the Cambrian.  The continents were flooded by shallow seas.  The supercontinent of Gondwana had just formed and was located near the South Pole.







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Paleoworld:


Season 2, Episode 3 - "The Earthshakers"