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.

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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.”

Triassic dinosaurs’ explosion, new study


This 16 April 2018 Italian language video is about the recent research into the early days of dinosaurs in the Dolomite mountains in Italy.

From the University of Bristol in England:

Dinosaurs ended — and originated — with a bang!

April 16, 2018

It is commonly understood that the dinosaurs disappeared with a bang — wiped out by a great meteorite impact on the Earth 66 million years ago.

But their origins have been less understood. In a new study, scientists from MUSE — Museum of Science, Trento, Italy, Universities of Ferrara and Padova, Italy and the University of Bristol show that the key expansion of dinosaurs was also triggered by a crisis — a mass extinction that happened 232 million years ago.

In the new paper, published today in Nature Communications, evidence is provided to match the two events — the mass extinction, called the Carnian Pluvial Episode, and the initial diversification of dinosaurs.

Dinosaurs had originated much earlier, at the beginning of the Triassic Period, some 245 million years ago, but they remained very rare until the shock events in the Carnian 13 million years later.

The new study shows just when dinosaurs took over by using detailed evidence from rock sequences in the Dolomites, in north Italy — here the dinosaurs are detected from their footprints.

First there were no dinosaur tracks, and then there were many. This marks the moment of their explosion, and the rock successions in the Dolomites are well dated. Comparison with rock successions in Argentina and Brazil, where the first extensive skeletons of dinosaurs occur, show the explosion happened at the same time there as well.

Lead author Dr Massimo Bernardi, Curator at MUSE and Research associate at Bristol’s School of Earth Sciences, said: “We were excited to see that the footprints and skeletons told the same story. We had been studying the footprints in the Dolomites for some time, and it’s amazing how clear cut the change from ‘no dinosaurs’ to ‘all dinosaurs’ was.”

The point of explosion of dinosaurs matches the end of the Carnian Pluvial Episode, a time when climates shuttled from dry to humid and back to dry again.

It was long suspected that this event had caused upheavals among life on land and in the sea, but the details were not clear. Then, in 2015, dating of rock sections and measurement of oxygen and carbon values showed just what had happened.

There were massive eruptions in western Canada, represented today by the great Wrangellia basalts — these drove bursts of global warming, acid rain, and killing on land and in the oceans.

Co-author Piero Gianolla, from the University of Ferrara, added: “We had detected evidence for the climate change in the Dolomites. There were four pulses of warming and climate perturbation, all within a million years or so. This must have led to repeated extinctions.”

Professor Mike Benton, also a co-author, from the University of Bristol, said: “The discovery of the existence of a link between the first diversification of dinosaurs and a global mass extinction is important.

“The extinction didn’t just clear the way for the age of the dinosaurs, but also for the origins of many modern groups, including lizards, crocodiles, turtles, and mammals — key land animals today.”

A new mass extinction has been identified during the Triassic period, some 232 million years ago — called the Carnian event. It was less easy to identify because the different sites around the world were hard to date and cross-match. But it was important because it marked the likely trigger for the explosive takeover of the Earth by dinosaurs: here.

Ichthyosaur discovery, one of largest animals ever


This 9 April 2018 video from England is called Scientists discover 250-MILLION-year-old jaw bone belonging to 26m reptile.

From the University of Manchester in England:

Giant ichthyosaur is one of largest animals ever

April 9, 2018

The 205 million-year-old jaw bone of a prehistoric reptile belongs to ‘one of the largest animals ever’ say a group of international palaeontologists.

The new discovery has also solved a 150 year old mystery of supposed ‘dinosaur bones’ from the UK.

The bone belongs to a giant ichthyosaur, a type of prehistoric aquatic reptile, and experts estimate the length of this specimen’s body would have been up to 26 metres. Approaching the size of a blue whale.

Fossil collector and co-author of the study, Paul de la Salle, found the bone on the beach at Lilstock, Somerset in May 2016. He later returned to the site and found even more pieces that together measured about one metre in length.

Paul said “Initially, the bone just looked like a piece of rock but, after recognising a groove and bone structure, I thought it might be part of a jaw from an ichthyosaur and immediately contacted ichthyosaur experts Dean Lomax (University of Manchester) and Prof. Judy Massare (SUNY College at Brockport, NY, USA) who expressed interest in studying the specimen. I also contacted Dr Ramues Gallois, a geologist who visited the site and determined the age of the specimen stratigraphically.

Lomax and Massare identified the specimen as an incomplete bone (called a surangular) from the lower jaw of a giant ichthyosaur. The bone would have made up only a portion of the entire skull. They compared it with several ichthyosaurs and visited the Royal Tyrrell Museum of Palaeontology in Alberta, Canada, and examined the largest ichthyosaur known, the shastasaurid Shonisaurus sikanniensis, which is 21 m long. They found similarities between the new specimen and S. sikanniensis which suggest the Lilstock specimen belongs to a giant shastasaurid-like ichthyosaur.

“As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in S. sikanniensis, the Lilstock specimen is about 25% larger. Other comparisons suggest the Lilstock ichthyosaur was at least 20-25 m. Of course, such estimates are not entirely realistic because of differences between species. Nonetheless, simple scaling is commonly used to estimate size, especially when comparative material is scarce.” Added Lomax.

In 1850, a large bone was described from the Late Triassic (208 million-years-old) of Aust Cliff, Gloucestershire, UK. Four other similarly incomplete bones were also found and described. Two of them are now missing and presumed destroyed. They have been identified as the limb bones of several dinosaurs (stegosaurs and sauropods), indeterminate dinosaurs and other reptiles.

However, with the discovery of the Lilstock specimen, this new study refutes previous identifications and also the most recent assertion that the Aust bones represent an early experiment of dinosaur-like gigantism in terrestrial reptiles. They are, in fact, jaw fragments of giant, previously unrecognised ichthyosaurs.

Dean added: “One of the Aust bones might also be an ichthyosaur surangular. If it is, by comparison with the Lilstock specimen, it might represent a much larger animal. To verify these findings, we need a complete giant Triassic ichthyosaur from the UK — a lot easier said than done!”

African Triassic paleontology, new study


This 2016 video is called Monsters and Dinosaurs | Triassic | Age of Dinosaur | Documentary Film HD.

From the University of Washington in the USA:

Decade of fossil collecting gives new perspective on Triassic period, emergence of dinosaurs

March 28, 2018

Summary: A project spanning countries, years and institutions has attempted to reconstruct what the southern end of the world looked like during the Triassic period, 252 to 199 million years ago.

After a great mass extinction shook the world about 252 million years ago, animal life outside of the ocean began to take hold. The earliest mammals entered the scene, and reptiles — including early dinosaurs — lived on Pangea, the name given to the giant landmass in which all of the world’s continents were joined as one.

A project spanning countries, years and institutions has attempted to reconstruct what the southern end of this world looked like during this period, known as the Triassic (252 to 199 million years ago). Led by paleontologists and geologists at the University of Washington, the team has uncovered new fossils in Zambia and Tanzania, examined previously collected fossils and analyzed specimens in museums around the world in an attempt to understand life in the Triassic across different geographic areas.

Findings from the past decade of fieldwork and analysis are reported in a publication of the Society of Vertebrate Paleontology, appearing online March 28. In total, 13 research papers detailing new fossils, geologic discoveries and ecological findings in the Triassic make up the society’s 2018 special-edition volume, published once a year in a competitive submission process.

“Most of what we know about the major mass extinction is from the South African Karoo Basin. I was always interested in understanding, do we see the exact same pattern around the world, or do we not?” said co-editor Christian Sidor, a UW biology professor and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture.

“The fossil record can be great to understand timing and sequence, but not always great at looking at things in a geographic context.”

Since 2007, Sidor and his team of students, postdoctoral researchers, paleontologists and geologists have visited the Ruhuhu Basin of Tanzania five times and the Luangwa and mid-Zambezi basins of Zambia four times. They lived there for about a month at a time, often hiking for miles to find fossil sites and camping in villages and national parks. Once, they were even awakened by the stomping and calls of elephants only feet from their camp.

Each site in Tanzania and Zambia contains its own collection of fossils from the Triassic and other periods, but the goal of this decade-long project was to look across locations hundreds and thousands of miles apart to find similarities in the fossil records. Two papers describe the regional patterns and similarities across much of what used to be Pangea.

“These papers highlight what a regional perspective we now have — we have the same fossils from Tanzania, Antarctica, Namibia and more”, Sidor said. “We’re getting a much better Southern Hemisphere perspective of what’s going on in the Triassic.”

Most of the papers in the special edition discuss new fossil findings from the paleontological digs. One explains the discovery of a new species of lizard-like reptile called a procolophonid. Another details Teleocrater, an early dinosaur relative that walked on four crocodile-like legs. This finding was reported in Nature last year, but the new paper describes the animal’s anatomy in fuller detail.

Most of the remaining papers describe other animals that were present in the Triassic besides the early dinosaurs.

“This was a time when dinosaurs were just stepping onto the stage, and they were not very big and not very remarkable animals then”, Sidor said. “These papers really round out what dinosaurs were competing with before they became the dominant reptiles on land.”

In addition to the 13 papers that make up the special edition, the team has published 24 peer-reviewed papers as part of this project in the past decade.

More than 2,200 fossils were collected across Tanzania and Zambia over the last decade of fieldwork. Of the special edition’s 27 authors, many participated in fieldwork with Sidor since 2007, including co-editor Sterling Nesbitt, a former postdoctoral researcher at the UW and now an assistant professor at Virginia Tech.

Fossil hunting is an experience every member of Sidor’s lab can have, from undergraduates through postdoctoral researchers. Sidor and a team are going again this August.

“This has been what my lab has done, and all of my students have been involved in some way,” he said. Four of Sidor’s students and two postdoctoral researchers are co-authors of papers in the new special edition.

Triassic reptile discovery in the USA


This 23 March 2018 video from the USA is called A tiny Triassic saurian from Connecticut and the early evolution of the diapsid feeding apparatus.

From Yale University in the USA:

Paleontologists put the bite on an ancient reptile from New England

March 23, 2018

Scientists have identified a new species of reptile from prehistoric Connecticut and, boy, does it have a mouth on it.

Named Colobops noviportensis, the creature lived 200 million years ago and had exceptionally large jaw muscles — setting it apart from other reptiles at the time. Even compared to the wide diversity of reptile species today, Colobops noviportensis had quite the bite.

“Colobops would have been a diminutive but plucky little beast, part of a little-known menagerie of small animals that lived among the first dinosaurs”, said Bhart-Anjan Bhullar, assistant professor and assistant curator in geology and geophysics at Yale, and senior author of a new paper about the discovery in the journal Nature Communications.

“Its tiny frame hid some big secrets”, Bhullar said. “Despite its lizard-like aspect, it is in fact an early branch-off of the lineage leading to dinosaurs and birds. Also, its little jaws could bite harder than anything else its size. Perhaps that big bite allowed it to feed on tough, armored prey impervious to weaker mouths.”

The lead author of the paper is Adam Pritchard, a former member of Bhullar’s lab who is now at the Smithsonian Institution.

Additional Yale authors of the paper are Jacques Gauthier, professor of geology and geophysics and curator of vertebrate paleontology and vertebrate zoology at the Peabody Museum; and Michael Hanson, a graduate student in geology and geophysics.

“This project was a great example of the process of science”, Pritchard said. “The skull was initially discovered in the mid-1960s. In the 1990s, the skull was subject to initial study in which it was identified as a cousin of a modern lizard-like reptile called a tuatara. Our study ups the ante again, using advanced CT scanning and 3D modeling to reveal all kinds of new features of the skull. The features are very distinctive, allowing us to establish a new species.”

The specimen is a quarter-sized skull discovered in Meriden, Conn., during roadwork in 1965. It has been part of the collections of the Yale Peabody Museum of Natural History for decades. The specimen’s new species name derives from Novus Portus, a Latinized version of New Haven — a reference to the New Haven Arkose geological formation.

The Yale team took a new look at the specimen. The researchers did a 3D reconstruction of the skull and discovered that it showed specialization in the jaw that was unprecedented in any other known small tetrapod, juvenile or adult.

“Comparisons with modern reptile dissections showed that it had incredibly well-developed jaw muscles for its size, suggesting an exceptional bite, even compared to the diversity of modern reptiles”, Pritchard said. “It’s a great illustration of the critical importance of fossils big and small for understanding the diversity of organisms.”

The researchers said the discovery means modern vertebrates originated in a world that was already populated by small and large-bodied physical extremes, in terms of how animals physically adapted to their environment.

The National Science Foundation and the Yale Peabody Museum of Natural History supported the research.

This video from the USA says about itself:

23 March 2018

Yale University paleontologist Bhart-Anjan Bhullar talks about Colobops noviportensis, a tiny reptile with exceptionally large jaw muscles. The extinct species was identified from a fossil initially discovered in Connecticut in the 1960s.