Jurassic ichthyosaur was warm-blooded, new research


This 15 June 2018 video says about itself:

Ichthyosaurs 101 | National Geographic

Meaning “fish lizard” in Greek, the aptly-named ichthyosaur once dominated the world’s oceans for millions of years. Learn about these prehistoric marine reptiles and see how features, such as basketball-sized eyes and a vertical tail, helped the ichthyosaur secure a place at the top of the ancient food chain.

From the North Carolina State University in the USA:

Soft tissue shows Jurassic ichthyosaur was warm-blooded, had blubber and camouflage

December 5, 2018

An ancient, dolphin-like marine reptile resembles its distant relative in more than appearance, according to an international team of researchers that includes scientists from North Carolina State University and Sweden’s Lund University. Molecular and microstructural analysis of a Stenopterygius ichthyosaur from the Jurassic (180 million years ago) reveals that these animals were most likely warm-blooded, had insulating blubber and used their coloration as camouflage from predators.

“Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals,” says research co-author Mary Schweitzer, professor of biological sciences at NC State with a joint appointment at the North Carolina Museum of Natural Sciences and visiting professor at Lund University. “We aren’t exactly sure of their biology either. They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness. This study reveals some of those biological mysteries.”

Johan Lindgren, associate professor at Sweden’s Lund University and lead author of a paper describing the work, put together an international team to analyze an approximately 180 million-year-old Stenopterygius fossil from the Holzmaden quarry in Germany.

“Both the body outline and remnants of internal organs are clearly visible,” says Lindgren. “Remarkably, the fossil is so well-preserved that it is possible to observe individual cellular layers within its skin.”

Researchers identified cell-like microstructures that held pigment organelles within the fossil’s skin, as well as traces of an internal organ thought to be the liver. They also observed material chemically consistent with vertebrate blubber, which is only found in animals capable of maintaining body temperatures independent of ambient conditions.

Lindgren sent samples from the fossil to international colleagues, including Schweitzer. The team conducted a variety of high-resolution analytical techniques, including time-of-flight secondary ion mass spectrometry (ToF SIMS), nanoscale secondary ion mass spectrometry (NanoSIMS), pyrolysis-gas chromatography/mass spectrometry, as well as immunohistological analysis and various microscopic techniques.

Schweitzer and NC State research assistant Wenxia Zheng extracted soft tissues from the samples and performed multiple, high-resolution immunohistochemical analyses. “We developed a panel of antibodies that we applied to all of the samples, and saw differential binding, meaning the antibodies for a particular protein — like keratin or hemoglobin — only bound to particular areas,” Schweitzer says. “This demonstrates the specificity of these antibodies and is strong evidence that different proteins persist in different tissues. You wouldn’t expect to find keratin in the liver, for example, but you would expect hemoglobin. And that’s what we saw in the responses of these samples to different antibodies and other chemical tools.”

Lindgren’s lab also found chemical evidence for subcutaneous blubber. “This is the first direct, chemical evidence for warm-bloodedness in an ichthyosaur, because blubber is a feature of warm-blooded animals,” Schweitzer says.

Taken together, the researchers’ findings indicate that the Stenopterygius had skin similar to that of a whale, and coloration similar to many living marine animals — dark on top and lighter on the bottom — which would provide camouflage from predators, like pterosaurs from above, or pliosaurs from below.

“Both morphologically and chemically, we found that although Stenopterygius would be loosely considered ‘reptiles,’ they lost the scaly skin associated with these animals — just as the modern leatherback sea turtle has,” Schweitzer says. “Losing the scales reduces drag and increases maneuverability underwater.

“This animal’s preservation is unusual, especially for a marine environment — but then, the Holzmaden formation is known for its exceptional preservation. This specimen has given us more evidence that these tissues and molecules can preserve for extremely long periods, and that soft tissue analysis can shed light on evolutionary patterns, relationships, and how ancient animals functioned in their environment.

“Our results were repeatable and consistent across labs. This work really shows what we’re capable of discovering when we perform a multidisciplinary, multi-institutional study of an exceptional specimen.”

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Jurassic carnivorous dinosaur from Oklahoma, USA


This 2 December 2018 video says about itself:

Saurophaganax – Lord of the Lizard-Eaters

150 million years ago, a giant predator stalked the lands of ancient Oklahoma.

New ancient Archaeopteryx bird discovery


This 26 October 2018 video says about itself:

Breaking News – Newly found species of the ‘first bird’ Archaeopteryx discovered

Scientists have discovered a new species of Archaeopteryx. Dubbed Archaeopteryx albersdoerferi (artist’s impression), the late species had a number of bird-like features.

From The University of Manchester in England:

New species of ‘missing link’ between dinosaurs and birds identified

October 25, 2018

Known as the ‘Icon of Evolution’ and ‘the missing link’ between dinosaurs and birds, Archaeopteryx has become one of the most famous fossil discoveries in palaeontology.

Now, as part of an international team of scientists, researchers at The University of Manchester have identified a new species of Archaeopteryx that is closer to modern birds in evolutionary terms.

Dr John Nudds, from the University’s School of Earth and Environmental Sciences, and the team have been re-examining one of the only 12 known specimens by carrying out the first ever synchrotron examination, a form of 3D X-ray analysis, of an Archaeopteryx.

Thanks to this new insight, the team says that this individual Archaeopteryx fossil, known as ‘specimen number eight’, is physically much closer to a modern bird than it is to a reptile. Therefore, it is evolutionary distinctive and different enough to be described as a new species — Archaeopteryx albersdoerferi.

The research, which is being published in journal Historical Biology, says that some of the differing skeletal characteristics of Archaeopteryx albersdoerferi include the fusion of cranial bones, different pectoral girdle (chest) and wing elements, and a reinforced configuration of carpals and metacarpals (hand) bones.

These characteristics are seen more in modern flying birds and are not found in the older Archaeopteryx lithographica species, which more resembles reptiles and dinosaurs.

Specimen number eight is the youngest of all the 12 known specimens by approximately half a million years. This age difference in comparison to the other specimens is a key factor in describing it as a new species.

Dr Nudds explains: “By digitally dissecting the fossil we found that this specimen differed from all of the others. It possessed skeletal adaptations which would have resulted in much more efficient flight. In a nutshell we have discovered what Archaeopteryx lithographica evolved into — i.e. a more advanced bird, better adapted to flying — and we have described this as a new species of Archaeopteryx.”

Archaeopteryx was first described as the ‘missing link’ between reptiles and birds in 1861 — and is now regarded as the link between dinosaurs and birds. Only 12 specimens have ever been found and all are from the late Jurassic of Bavaria, now Germany, dating back approximately 150 million years.

Lead author, Dr Martin Kundrát, from the University of Pavol Jozef Šafárik, Slovakia, said: “This is the first time that numerous bones and teeth of Archaeopteryx were viewed from all aspects including exposure of their inner structure. The use of synchrotron microtomography was the only way to study the specimen as it is heavily compressed with many fragmented bones partly or completely hidden in limestone.”

Dr Nudds added: “Whenever a missing link is discovered, this merely creates two further missing links — what came before, and what came after! What came before was discovered in 1996 with the feathered dinosaurs in China. Our new species is what came after. It confirms Archaeopteryx as the first bird, and not just one of a number of feathered theropod dinosaurs, which some authors have suggested recently. You could say that it puts Archaeopteryx back on its perch as the first bird!”

Dinosaur age predatory fish discovery


This image shows a new piranha-like fish from Jurassic seas with sharp, pointed teeth that probably fed on the fins of other fishes. From the time of dinosaurs and from the same deposits that contained Archaeopteryx, scientists recovered both this flesh-tearing fish and its scarred prey. Credit: M. Ebert and T. Nohl

From ScienceDaily:

150-million-year old, piranha-like specimen is earliest known flesh-eating fish

October 18, 2018

Researchers reporting in Current Biology on October 18 have described a remarkable new species of fish that lived in the sea about 150 million years ago in the time of the dinosaurs. The new species of bony fish had teeth like a piranha, which the researchers suggest they used as piranhas do: to bite off chunks of flesh from other fish.

As further support for that notion, the researchers also found the victims: other fish that had apparently been nibbled on in the same limestone deposits in South Germany (the quarry of Ettling in the Solnhofen region) where this piranha-like fish was found.

“We have other fish from the same locality with chunks missing from their fins”, says David Bellwood of James Cook University, Australia. “This is an amazing parallel with modern piranhas, which feed predominantly not on flesh but the fins of other fishes. It’s a remarkably smart move as fins regrow, a neat renewable resource. Feed on a fish and it is dead; nibble its fins and you have food for the future.”

The newly described fish is part of the world famous collections in the Jura-Museum in Eichstätt. It comes from the same limestone deposits that contained Archaeopteryx.

Careful study of the fossilized specimen’s well-preserved jaws revealed long, pointed teeth on the exterior of the vomer, a bone forming the roof of the mouth, and at the front of both upper and lower jaws. Additionally, there are triangular teeth with serrated cutting edges on the prearticular bones that lie along the side of the lower jaw.

The tooth pattern and shape, jaw morphology, and mechanics suggest a mouth equipped to slice flesh or fins, the international team of researchers report. The evidence points to the possibility that the early piranha-like fish may have exploited aggressive mimicry in a striking parallel to the feeding patterns of modern piranha.

“We were stunned that this fish had piranha-like teeth,” says Martina Kölbl-Ebert of Jura-Museum Eichstätt (JME-SNSB). “It comes from a group of fishes (the pycnodontids) that are famous for their crushing teeth. It is like finding a sheep with a snarl like a wolf. But what was even more remarkable is that it was from the Jurassic. Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time. Sharks have been able to bite out chunks of flesh but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later.”

Or, so it had seemed.

“The new finding represents the earliest record of a bony fish that bit bits off other fishes, and what’s more it was doing it in the sea”, Bellwood says, noting that today’s piranhas all live in freshwater. “So when dinosaurs were walking the earth and small dinosaurs were trying to fly with the pterosaurs, fish were swimming around their feet tearing the fins or flesh off each other.”

The researchers call the new find a “staggering example of evolutionary versatility and opportunism.” With one of the world’s best known and studied fossil deposits continuing to throw up such surprises, they intend to keep up the search for even more fascinating finds.

Big dinosaur discovery in South Africa


This 27 September 2018 video says about itself:

Ledumahadi mafube – New Jurassic Giant of South Africa

A new species of a giant dinosaur has been found in South Africa’s Free State Province.

From the University of the Witwatersrand in South Africa:

Ledumahadi mafube: South Africa’s new Jurassic giant

September 27, 2018

A new species of a giant dinosaur has been found in South Africa’s Free State Province. The plant-eating dinosaur, named Ledumahadi mafube, weighed 12 tonnes and stood about four metres high at the hips. Ledumahadi mafube was the largest land animal alive on Earth when it lived, nearly 200 million years ago. It was roughly double the size of a large African elephant.

A team of international scientists, led by University of the Witwatersrand (Wits) palaeontologist Professor Jonah Choiniere, described the new species in the journal Current Biology today.

The dinosaur’s name is Sesotho for “a giant thunderclap at dawn” (Sesotho is one of South Africa’s 11 official languages and an indigenous language in the area where the dinosaur was found).

“The name reflects the great size of the animal as well as the fact that its lineage appeared at the origins of sauropod dinosaurs”, said Choiniere. “It honours both the recent and ancient heritage of southern Africa.”

Ledumahadi mafube is one of the closest relatives of sauropod dinosaurs. Sauropods, weighing up to 60 tonnes, include well-known species like Brontosaurus. All sauropods ate plants and stood on four legs, with a posture like modern elephants. Ledumahadi evolved its giant size independently from sauropods, and although it stood on four legs, its forelimbs would have been more crouched. This caused the scientific team to consider Ledumahadi an evolutionary “experiment” with giant body size.

Ledumahadi’s fossil tells a fascinating story not only of its individual life history, but also the geographic history of where it lived, and of the evolutionary history of sauropod dinosaurs.

“The first thing that struck me about this animal is the incredible robustness of the limb bones”, says lead author, Dr Blair McPhee. “It was of similar size to the gigantic sauropod dinosaurs, but whereas the arms and legs of those animals are typically quite slender, Ledumahadi’s are incredibly thick. To me this indicated that the path towards gigantism in sauropodomorphs was far from straightforward, and that the way that these animals solved the usual problems of life, such as eating and moving, was much more dynamic within the group than previously thought.”

The research team developed a new method, using measurements from the “arms” and “legs” to show that Ledumahadi walked on all fours, like the later sauropod dinosaurs, but unlike many other members of its own group alive at its time such as Massospondylus. The team also showed that many earlier relatives of sauropods stood on all fours, that this body posture evolved more than once, and that it appeared earlier than scientists previously thought.

Ledumahadi mafube is the first of the giant sauropodomorphs of the Jurassic. Credit: Wits University

“Many giant dinosaurs walked on four legs but had ancestors that walked on two legs. Scientists want to know about this evolutionary change, but amazingly, no-one came up with a simple method to tell how each dinosaur walked, until now”, says Dr Roger Benson.

By analysing the fossil’s bone tissue through osteohistological analysis, Dr Jennifer Botha-Brink from the South African National Museum in Bloemfontein established the animal’s age.

“We can tell by looking at the fossilised bone microstructure that the animal grew rapidly to adulthood. Closely-spaced, annually deposited growth rings at the periphery show that the growth rate had decreased substantially by the time it died”, says Botha-Brink. This indicates that the animal had reached adulthood.

“It was also interesting to see that the bone tissues display aspects of both basal sauropodomorphs and the more derived sauropods, showing that Ledumahadi represents a transitional stage between these two major groups of dinosaurs.”

Ledumahadi lived in the area around Clarens in South Africa’s Free State Province. This is currently a scenic mountainous area, but looked much different at that time, with a flat, semi-arid landscape and shallow, intermittently dry streambeds.

“We can tell from the properties of the sedimentary rock layers in which the bone fossils are preserved that 200 million years ago most of South Africa looked a lot more like the current region around Musina in the Limpopo Province of South Africa, or South Africa’s central Karoo”, says Dr Emese Bordy.

Ledumahadi is closely related to other gigantic dinosaurs from Argentina that lived at a similar time, which reinforces that the supercontinent of Pangaea was still assembled in the Early Jurassic. “It shows how easily dinosaurs could have walked from Johannesburg to Buenos Aires at that time”, says Choiniere.

South Africa’s Minister of Science and Technology Mmamoloko Kubayi-Ngubane says the discovery of this dinosaur underscores just how important South African palaeontology is to the world.

“Not only does our country hold the Cradle of Humankind, but we also have fossils that help us understand the rise of the gigantic dinosaurs. This is another example of South Africa taking the high road and making scientific breakthroughs of international significance on the basis of its geographic advantage, as it does in astronomy, marine and polar research, indigenous knowledge, and biodiversity”, says Kubayi-Ngubane.

The research team behind Ledumahadi includes South African-based palaeoscientists, Dr Emese Bordy and Dr Jennifer Botha-Brink, from the University of Cape Town and the South African National Museum in Bloemfontein, respectively.

The project also had a strong international component with the collaboration of Professor Roger BJ Benson of Oxford University and Dr Blair McPhee, currently residing in Brazil.

“South Africa employs some of the world’s top palaeontologists and it was a privilege to be able to build a working group with them and leading researchers in the UK”, says Choiniere, who recently emigrated from the USA to South Africa. “Dinosaurs didn’t observe international boundaries and it’s important that our research groups don’t either.”

Jurassic marine reptiles, new research


This 2013 BBC video says about itself:

In 2006, a fossil was dug out of a frozen [Svalbard] island high in the Arctic. It was a colossal marine reptile, twice as big as most ocean predators, at 15 metres long and weighing about 45 tonnes. This was Predator X, the most powerful marine reptile ever discovered. Its skull alone was nearly twice the size of a Tyrannosaurus rex‘s, and its bite force unmatched by anything in the Jurassic seas.

From the University of Edinburgh in Scotland:

Fossil teeth show how Jurassic reptiles adapted to changing seas

September 4, 2018

Marine predators that lived in deep waters during the Jurassic Period thrived as sea levels rose, while species that dwelled in the shallows died out, research suggests.

A study of fossilised teeth has shed light on how reptiles adapted to major environmental changes more than 150 million years ago, and how sea life might respond today.

It also reveals for the first time that the broad structure of food chains beneath the sea has remained largely unchanged since the Jurassic era.

For more than 18 million years, diverse reptile species lived together in tropical waters that stretched from present-day northern France to Yorkshire in the north of England.

Until now, however, little was known about the structure of the food chain in this region — called the Jurassic Sub-Boreal Seaway — or how it changed as sea levels rose.

By analysing the shape and size of teeth spanning this 18-million-year period when water levels fluctuated, palaeontologists at the University of Edinburgh found that species belonged to one of five groups based on their teeth, diet and which part of the ocean they inhabited.

The pattern is very similar to the food chain structure of modern oceans, where many different species are able to co-exist in the same area because they do not compete for the same resources, the team says.

As global sea levels rose, reptiles that lived in shallow waters and caught fish using thin, piercing teeth declined drastically, researchers found.

At the same time, larger species that inhabited deeper, open waters began to thrive. These reptiles had broader teeth for crunching and cutting prey.

Deep-water species may have flourished as a result of major changes in ocean temperature and chemical make-up that also took place during the period, the team says. This could have increased levels of nutrients and prey in deep waters, benefitting species that lived there.

The study offers insights into how species at the top of marine food chains today might respond to rapid environmental changes — including climate change, pollution and rising temperatures.

The study, which also involved the University of Bristol, is published in the journal Nature Ecology & Evolution. It was supported by the Leverhulme Trust, Marie Sklodowska-Curie Actions, Systematics Research Fund, Palaeontographical Society and Palaeontological Association.

Davide Foffa, of the University of Edinburgh’s School of GeoSciences, who led the study, said: “Studying the evolution of these animals was a real — and rare — treat, and has offered a simple yet powerful explanation for why some species declined as others prospered. This work reminds us of the relevance of palaeontology by revealing the parallels between past and present-day ocean ecosystems.”

Dr Steve Brusatte, also of the University’s School of GeoSciences, said: “Teeth are humble fossils, but they reveal a grand story of how sea reptiles evolved over millions of years as their environments changed. Changes in these Jurassic reptiles parallel changes in dolphins and other marine species that are occurring today as sea-levels rise, which speaks to how important fossils are for understanding our modern world.”

Reptile to mammal evolution, new discovery


This 29 August 2018 video says about itself:

Pictured are CT scans of the skulls of, left to right, a tuatara hatchling (modern reptile), one of the Kayentatherium offspring, and a 27-day-old opossum (modern mammal), shown at the same magnification. This shows that the brains—and therefore the skulls—of young mammals, such as the opossum, are rounded and relatively large.

As the mammal class developed, it grew to favour high investment in relatively few offspring with bigger brains.

Pictured is a CT scan of part of the specimen showing a maternal vertebra (gray) with bones of the babies (colours) in their original positions. Finding well-preserved young from the age of the dinosaurs is particularly unusual since they are often destroyed – or eaten – after their death.

Pictured here are the skulls of the 38 Kayentatherium wellesi babies found alongside the adult specimen, which researchers believe is their mother (pictured left for scale).

From the University of Texas at Austin in the USA:

Mammal forerunner that reproduced like a reptile sheds light on brain evolution

August 29, 2018

Compared with the rest of the animal kingdom, mammals have the biggest brains and produce some of the smallest litters of offspring. A newly described fossil of an extinct mammal relative — and her 38 babies — is among the best evidence that a key development in the evolution of mammals was trading brood power for brain power.

The find is among the rarest of the rare because it contains the only known fossils of babies from any mammal precursor, said researchers from The University of Texas at Austin who discovered and studied the fossilized family. But the presence of so many babies — more than twice the average litter size of any living mammal — revealed that it reproduced in a manner akin to reptiles. Researchers think the babies were probably developing inside eggs or had just recently hatched when they died.

The study, published in the journal Nature on Aug. 29, describes specimens that researchers say may help reveal how mammals evolved a different approach to reproduction than their ancestors, which produced large numbers of offspring.

“These babies are from a really important point in the evolutionary tree”, said Eva Hoffman, who led research on the fossil as a graduate student at the UT Jackson School of Geosciences. “They had a lot of features similar to modern mammals, features that are relevant in understanding mammalian evolution.”

Hoffman co-authored the study with her graduate adviser, Jackson School Professor Timothy Rowe.

The mammal relative belonged to an extinct species of beagle-size plant-eaters called Kayentatherium wellesi that lived alongside dinosaurs about 185 million years ago. Like mammals, Kayentatherium probably had hair.

When Rowe collected the fossil more than 18 years ago from a rock formation in Arizona, he thought that he was bringing a single specimen back with him. He had no idea about the dozens of babies it contained.

Sebastian Egberts, a former graduate student and fossil preparator at the Jackson School, spotted the first sign of the babies years later when a grain-sized speck of tooth enamel caught his eye in 2009 as he was unpacking the fossil.

“It didn’t look like a pointy fish tooth or a small tooth from a primitive reptile”, said Egberts, who is now an instructor of anatomy at the Philadelphia College of Osteopathic Medicine. “It looked more like a molariform tooth (molar-like tooth) — and that got me very excited.”

A CT scan of the fossil revealed a handful of bones inside the rock. However, it took advances in CT-imaging technology during the next 18 years, the expertise of technicians at UT Austin’s High-Resolution X-ray Computed Tomography Facility, and extensive digital processing by Hoffman to reveal the rest of the babies — not only jaws and teeth, but complete skulls and partial skeletons.

The 3D visualizations Hoffman produced allowed her to conduct an in-depth analysis of the fossil that verified that the tiny bones belonged to babies and were the same species as the adult. Her analysis also revealed that the skulls of the babies were like scaled-down replicas of the adult, with skulls a tenth the size but otherwise proportional. This finding is in contrast to mammals, which have babies that are born with shortened faces and bulbous heads to account for big brains.

The brain is an energy-intensive organ, and pregnancy — not to mention childrearing — is an energy-intensive process. The discovery that Kayentatherium had a tiny brain and many babies, despite otherwise having much in common with mammals, suggests that a critical step in the evolution of mammals was trading big litters for big brains, and that this step happened later in mammalian evolution.

“Just a few million years later, in mammals, they unquestionably had big brains, and they unquestionably had a small litter size”, Rowe said.

The mammalian approach to reproduction directly relates to human development — including the development of our own brains. By looking back at our early mammalian ancestors, humans can learn more about the evolutionary process that helped shape who we are as a species, Rowe said.

“There are additional deep stories on the evolution of development, and the evolution of mammalian intelligence and behavior and physiology that can be squeezed out of a remarkable fossil like this now that we have the technology to study it”, he said.

Funding for the research was provided by the National Science Foundation, The University of Texas Geology Foundation and the Jackson School of Geosciences.