Triassic, earliest dinosaurs video


This 5 September 2018 video says about itself:

In this video we shall take a look into the earliest and first dinosaurs to have ever existed in this world.

These early dinosaurs are the oldest to be discovered in fossils of the Triassic age timeline.

The earliest dinosaurs are small in size and are mainly bipedal. … The comparison of the first dinosaurs and the large dinosaurs is really contrasting since the larger dinosaurs dwarf the early dinosaurs in height and weight.

The Eoraptor was once thought to be the earliest dinosaur to have existed, but then the Eoraptor lost that title to other early dinosaurs like the Saturnalia and then to the Nyasasaurus.

The Saturnalia predates the Eoraptor by 1 million years and the Nyasasaurus predates the others by more than 10 million years.

The Nyasasaurus is the earliest dinosaur we know, but definitely not the first since there is a probability that other dinosaurs might be found in the future. So, enjoy this video on the First / earliest dinosaurs comparison and timeline. The timeline is in the millions of years in the Triassic.

Timeline: Riojasaurus – 227 MYA, Alwalkeria/Herrerasaurus/Pisanosaurus/Saurikosaurus/Chromogisaurus – 230 MYA, Eoraptor – 231 MYA, Saturnalia – 232 MYA, Spondylosoma – 242 MYA and Nyasasaurus – 243 MYA.

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Permian-Triassic mass extinction, new research


This 2017 video says about itself:

The Permian–Triassic extinction event, colloquially known as the Great Dying, the End Permian or the Great Permian Extinction, occurred about 252 million years ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras.

It is the Earth’s most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all families and 83% of all genera became extinct.

Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event, possibly up to 10 million years, although studies in Bear Lake County near the Idaho city of Paris showed a quick and dynamic rebound in a marine ecosystem, illustrating the remarkable resiliency of life.

From the University of Tennessee at Knoxville in the USA:

Geologists uncover new clues about largest mass extinction ever

August 27, 2018

A new study could help explain the driving force behind the largest mass extinction in the history of earth, known as the End-Permian Extinction.

The event, also known as the Great Dying, occurred around 250 million years ago when a massive volcanic eruption in what is today the Russian province of Siberia sent nearly 90 percent of all life right into extinction. Geologists call this eruption the Siberian Flood Basalts, and it ran for almost a million years.

“The scale of this extinction was so incredible that scientists have often wondered what made the Siberian Flood Basalts so much more deadly than other similar eruptions”, said Michael Broadley, a postdoctoral researcher at the Centre for Petrographic and Geochemical Research in Vandœuvre-lès-Nancy, France, and lead author of the paper.

The work, which was published in Nature Geoscience, was co-authored by Lawrence (Larry) Taylor, the former director of the Planetary Geosciences Institute at the University of Tennessee, Knoxville. Taylor, whose prolific career at UT spanned 46 years, passed away in September 2017 at age 79.

According to Broadley, “Taylor was instrumental in supplying samples of mantle xenoliths, rock sections of the lithosphere [a section of the planet located between the crust and the mantle] that get captured by the passing magma and erupted to the surface during the volcanic explosion. Taylor also provided advice throughout the study.”

Through the analysis of samples, Broadley and his team tried to determine the composition of the lithosphere. They found that before the Siberian Flood Basalts took place, the Siberian lithosphere was heavily loaded with chlorine, bromine, and iodine, all chemical elements from the halogen group. However, these elements seem to have disappeared after the volcanic eruption.

“We concluded that the large reservoir of halogens that was stored in the Siberian lithosphere was sent into the earth’s atmosphere during the volcanic explosion, effectively destroying the ozone layer at the time and contributing to the mass extinction”, Broadley said.

Using the fossil record to accurately estimate the timing and pace of past mass extinctions is no easy task, and a new study highlights how fossil evidence can produce a misleading picture if not interpreted with care. Florida Museum of Natural History researchers used a series of 130-foot cores drilled from the Po Plain in northeastern Italy to test a thought experiment: Imagine catastrophe strikes the Adriatic Sea, swiftly wiping out modern marine life. Could this hypothetical mass extinction be reconstructed correctly from mollusks — hard-shelled animals such as oysters and mussels — preserved in these cores? Here.

Ancient shellless turtle discovery


This 22 August 2018 video says about itself:

Newly discovered ancient turtle didn’t have a shell, scientists say

The six foot-long animal, named Eorhynchochelys sinensis, lived more than 200 million years ago.

From the Field Museum in the USA:

Fossil turtle didn’t have a shell yet, but had the first toothless turtle beak

228-million-year-old fossil sheds light on how turtles evolved

August 22, 2018

There are a couple of key features that make a turtle a turtle: its shell, for one, but also its toothless beak. A newly-discovered fossil turtle that lived 228 million years ago is shedding light on how modern turtles developed these traits. It had a beak, but while its body was Frisbee-shaped, its wide ribs hadn’t grown to form a shell like we see in turtles today.

“This creature was over six feet long, it had a strange disc-like body and a long tail, and the anterior part of its jaws developed into this strange beak,” says Olivier Rieppel, a paleontologist at Chicago’s Field Museum and one of the authors of a new paper in Nature. “It probably lived in shallow water and dug in the mud for food.”

The new species has been christened Eorhynchochelys sinensis — a mouthful, but with a straightforward meaning. Eorhynchochelys (“Ay-oh-rink-oh-keel-is”) means “dawn beak turtle” — essentially, first turtle with a beak — while sinensis, meaning “from China,” refers to the place where it was found by the study’s lead author, Li Chun of China’s Institute of Vertebrate Paleontology and Paleoanthropology.

Eorhynchochelys isn’t the only kind of early turtle that scientists have discovered — there is another early turtle with a partial shell but no beak. Until now, it’s been unclear how they all fit into the reptile family tree. “The origin of turtles has been an unsolved problem in paleontology for many decades”, says Rieppel. “Now with Eorhynchochelys, how turtles evolved has become a lot clearer.”

The fact that Eorhynchochelys developed a beak before other early turtles but didn’t have a shell is evidence of mosaic evolution — the idea that traits can evolve independently from each other and at a different rate, and that not every ancestral species has the same combination of these traits. Modern turtles have both shells and beaks, but the path evolution took to get there wasn’t a straight line. Instead, some turtle relatives got partial shells while others got beaks, and eventually, the genetic mutations that create these traits occurred in the same animal.

“This impressively large fossil is a very exciting discovery giving us another piece in the puzzle of turtle evolution,” says Nick Fraser, an author of the study from National Museums Scotland. “It shows that early turtle evolution was not a straightforward, step-by-step accumulation of unique traits but was a much more complex series of events that we are only just beginning to unravel.”

Fine details in the skull of Eorhynchochelys solved another turtle evolution mystery. For years, scientists weren’t sure if turtle ancestors were part of the same reptile group as modern lizards and snakesdiapsids, which early in their evolution had two holes on the sides of their skulls — or if they were anapsids that lack these openings. Eorhynchochelys’s skull shows signs that it was a diapsid. “With Eorhynchochelys’s diapsid skull, we know that turtles are not related to the early anapsid reptiles, but are instead related to evolutionarily more advanced diapsid reptiles. This is cemented, the debate is over”, says Rieppel.

The study’s authors say that their findings, both about how and when turtles developed shells and their status as diapsids, will change how scientists think about this branch of animals. “I was surprised myself,” says Rieppel. “Eorhynchochelys makes the turtle family tree make sense. Until I saw this fossil, I didn’t buy some of its relatives as turtles. Now, I do.”

This study was contributed to by Institute of Vertebrate Paleontology and Paleoanthropology, the CAS Center for Excellence in Life and Paleoenvironment, National Museums Scotland, the Field Museum, and the Canadian Museum of Nature.

Dinosaurs’ origins, video


This 27 July 2018 video says about itself:

How Dinosaurs Took Over The World

Dinosaurs were the true kings of the Jurassic and Cretaceous periods. For millions of years, Velociraptor, T-Rex, and your other favorites reigned supreme. But they weren’t always on top. At first, dinos were only the size of a dog, after all. Here’s how dinosaurs conquered the world.

Long-necked dinosaurs, why so big?


This video says about itself:

Argentinian researchers discover the oldest giant dinosaur species that inhabited the Earth

9 July 2018

Scientists presented Ingentia prima, the first giant dinosaur that inhabited the planet more than 200 million years ago. It exceeds three times the size of the largest Triassic dinosaurs known to date. The discovery was made at the Balde de Leyes deposit, southeast of the province of San Juan.

By Carolyn Gramling, 11:49am, July 10, 2018:

Long-necked dinosaurs grew to be giants in more ways than one

Fossils suggest some early sauropod relatives grew massive using a previously unknown method

For sauropods — the largest animals known to have walked on Earth — there may have been more than one way to get gigantic.

Most early relatives of the herbivorous dinosaurs have a suite of features once thought to be the essential blueprint for gigantism, such as sturdy pillarlike legs, elongated necks and forelimbs, and bones that grew continuously rather than in seasonal spurts. But an analysis of fossils of sauropodomorphs — a group that includes sauropods and some ancestors and similarly shaped relatives— suggests that some of the dinos may have had a different strategy for becoming behemoths, researchers report online July 9 in Nature Ecology and Evolution.

Paleontologist Cecilia Apaldetti of the Universidad Nacional de San Juan in Argentina and colleagues examined four sauropodomorphs, including one newly identified species that the team dubbed Ingentia prima and three already known specimens of a sauropodomorph called Lessemsaurus sauropoides. Dating to the Late Triassic, between 237 million and 201 million years ago, these “Lessemsauridae” were far from puny: The animals weighed in at an estimated 7 to 10 metric tons, larger than an African elephant.

All four specimens showed a combination of features that was distinct from sauropods as well as from other sauropodomorphs. Instead of upright, pillarlike legs, the dinos had crouched hind limbs and flexed front limbs, with elbows splayed slightly outward. Patterns of bone growth in the fossils also suggest that the animals grew in cyclical spurts rather than continuously. However, their bone growth was extremely rapid, a feature unique to this group, Apaldetti says. “They grew in a cyclical but extremely accelerated growth, at a speed even higher than that of the giants that grew continuously.”

Like later sauropods, I. prima and L. sauropoides also appear to have had a birdlike respiratory system, the researchers found. Air sacs within the animals’ vertebrae provided large reserves of oxygenated air, helped keep their bodies cool despite their large size, and lightened the weight of their vertebrae.

Martin Sander, a vertebrate paleontologist at Universität-Bonn in Germany, says that I. prima presents the best proof yet that these sauropodomorphs had this birdlike respiratory system, a fact that wasn’t previously determined. However, he says he is not convinced that the Lessemsauridae were on a separate track toward gigantism. “For me, it’s more of an intermediate stage”, Sander says.

That sentiment is echoed by Jeffrey Wilson, a vertebrate paleontologist at the University of Michigan in Ann Arbor. Lessemsauridae bone growth was cyclical, but that doesn’t necessarily mean the cycles were seasonal; there may have been long time lags in between growth spurts, part of a transition to more sauropod-like growth patterns, Wilson says. “One of the things I think future work will do is help resolve the ambiguity over whether the Lessemsauridae were taking their own adventure into gigantism.”

The Lessemsauridae may have developed their growth strategy some 30 million years earlier than Jurassic sauropods, such as Brachiosaurus and Diplodocus, Apaldetti notes. But ultimately, the Jurassic giants “were more successful”, she says — they outweighed the sauropodomorphs by as much as 60 tons, and outlasted them by tens of millions of years.

Triassic reptiles, unrelated to, but looking like, modern animals


This video from the USA says about itself:

Why Triassic Animals Were Just the Weirdest

5 June 2018

The Triassic was full of creatures that look a lot like other, more modern species, even though they’re not closely related at all.

The reason for this has to do with how evolution works and with the timing of the Triassic itself: when life was trapped between two mass extinctions.

Thanks to Ceri Thomas for the Drepanosaurus reconstruction. Check out more of Ceri’s paleoart at http://alphynix.tumblr.com and http://nixillustration.com.

And thanks as always to Nobumichi Tamura for allowing us to use his wonderful paleoart: http://spinops.blogspot.com/.

Finally, thanks to Emilio Rolandia, Matt Celeskey, and Studio 252mya for their excellent images as well.

World’s oldest lizard fossil discovery


This video says about itself:

Megachirella – The mother of all lizards

19 May 2018

In this video the authors talk about the significance of the discovery and take us behind the scenes of the research project.

From the University of Bristol in England:

World’s oldest lizard fossil discovered

May 30, 2018

An international team of paleontologists, which includes the University of Bristol, have identified the world’s oldest lizard, providing key insight into the evolution of modern lizards and snakes.

The 240-million-year-old fossil, Megachirella wachtleri, is the most ancient ancestor of all modern lizards and snakes, known as squamates, the new study, published today in the journal Nature, shows.

The fossil, along with data from both living and extinct reptiles — which involved anatomical data drawn from CT scans and DNA — suggests the origin of squamates is even older, taking place in the late Permian period, more than 250 million years ago.

Tiago Simões, lead author and PhD student from the University of Alberta in Canada, said: “The specimen is 75 million years older than what we thought were the oldest fossil lizards in the entire world and provides valuable information for understanding the evolution of both living and extinct squamates.”

Currently, there are 10,000 species of lizards and snakes around the world — twice as many different species as mammals. Despite this modern diversity, scientists did not know much about the early stages of their evolution.

Tiago Simões added: “It is extraordinary when you realize you are answering long-standing questions about the origin of one of the largest groups of vertebrates on Earth.”

Co-author, Dr Michael Caldwell, also from the University of Alberta, added: “Fossils are our only accurate window into the ancient past. Our new understanding of Megachirella is but a point in ancient time, but it tells us things about the evolution of lizards that we simply cannot learn from any of the 9000 or so species of lizards and snakes alive today.”

Originally found in the early 2000s in the Dolomites Mountains of Northern Italy, researchers considered it an enigmatic lizard-like reptile but could not reach conclusive placement, and it ramained nearly unnoticed by the international community.

In order to better understand both the anatomy of Megachirella and the earliest evolution of lizards and snakes the authors assembled the largest reptile dataset ever created.

The authors combined it with several new anatomical information from Megachirella obtained from high-resolution CT scans.

All this new information was analysed using state of the art methods to assess relationships across species, revealing that the once enigmatic reptile was actually the oldest known squamate.

Co-author Dr Randall Nydam of the Midwestern University in Arizona, said: “At first I did not think Megachirella was a true lizard, but the empirical evidence uncovered in this study is substantial and can lead to no other conclusion.”

Co-author Dr Massimo Bernardi from MUSE — Science Museum, Italy and University of Bristol’s School of Earth Sciences, added: “This is the story of the re-discovery of a specimen and highlights the importance of preserving naturalistic specimens in well maintained, publicly accessible collections.

“New observations, that could arise from the use of new techniques — as for the mCT data we have obtained here, could provide a completely new understanding even of long-known specimens.”