Dinosaur eggs, new research


This 2015 video is called Fossilized Dinosaur Eggs Unearthed in South China.

From the American Chemical Society in the USA:

Cracking the secrets of dinosaur eggshells

October 28, 2020

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.

Gliding dinosaurs, new research


This 2017 video says about itself:

The Five-Winged Dinosaur

Microraptor was a very important discovery that added a great deal to our knowledge on how birds evolved from dinosaur ancestors. This creature has helped to create a better picture of the evolution of flightless dinosaurs to fully flight-capable ones, and the quality of its incredible fossils has even allowed scientists to reveal what colour it was when Microraptor was alive.

From ScienceDaily:

These two bird-sized dinosaurs evolved the ability to glide, but weren’t great at it

October 22, 2020

Despite having bat-like wings, two small dinosaurs, Yi and Ambopteryx, struggled to fly, only managing to glide clumsily between the trees where they lived, researchers report October 22 in the journal iScience. Unable to compete with other tree-dwelling dinosaurs and early birds, they went extinct after just a few million years. The findings support that dinosaurs evolved flight in several different ways before modern birds evolved.

“Once birds got into the air, these two species were so poorly capable of being in the air that they just got squeezed out,” says first author Thomas Dececchi, Assistant Professor of Biology at Mount Marty University. “Maybe you can survive a few million years underperforming, but you have predators from the top, competition from the bottom, and even some small mammals adding into that, squeezing them out until they disappeared.”

Yi and Ambopteryx were small animals from Late Jurassic China, living about 160 million years ago. Weighing in at less than two pounds, they are unusual examples of theropod dinosaurs, the group that gave rise to birds. Most theropods were ground-loving carnivores, but Yi and Ambopteryx were at home in the trees and lived on a diet of insects, seeds, and other plants.

Curious about how these animals fly, Dececchi and his collaborators scanned fossils using laser-stimulated fluorescence (LSF), a technique that uses laser light to pick up soft-tissue details that can’t be seen with standard white light. Later, the team used mathematical models to predict how they might have flown, testing many different variables like weight, wingspan, and muscle placement.

“They really can’t do powered flight. You have to give them extremely generous assumptions in how they can flap their wings. You basically have to model them as the biggest bat, make them the lightest weight, make them flap as fast as a really fast bird, and give them muscles higher than they were likely to have had to cross that threshold,” says Dececchi. “They could glide, but even their gliding wasn’t great.”

While gliding is not an efficient form of flight, since it can only be done if the animal has already climbed to a high point, it did help Yi and Ambopteryx stay out of danger while they were still alive.

“If an animal needs to travel long distances for whatever reason, gliding costs a bit more energy at the start, but it’s faster. It can also be used as an escape hatch. It’s not a great thing to do, but sometimes it’s a choice between losing a bit of energy and being eaten,” says Dececchi. “Once they were put under pressure, they just lost their space. They couldn’t win on the ground. They couldn’t win in the air. They were done.”

The researchers are now looking at the muscles that powered Yi and Ambopteryx to construct an accurate image of these bizarre little creatures. “I’m used to working with the earliest birds, and we sort of have an idea of what they looked like already,” Dececchi says. “To work where we’re just trying to figure out the possibilities for a weird creature is kind of fun.”

The authors were supported by Mount Marty University and The University of Hong Kong.

Snakes during the night, new research


This 6 September 2020 video says about itself:

12 Most Beautiful Snakes in the World

With over 3,000 snake species known to humans, it’s no surprise they come in all sorts of shapes, colors, and patterns. If you too think we spend a little too much time fearing these slithering creatures instead of admiring their natural beauty, then stick around, because today we’re bringing you The 12 Most Beautiful Snakes in the World. Seriously, #2 is so gorgeous, it’ll leave you wondering how you could ever fear one of these majestic creatures again. Okay, probably not––but you get the point.

Anyhow, strap yourselves in and let’s take a look at some of these magnificent snakes.

From the University of Houston in Texas in the USA:

How do snakes ‘see’ in the dark? Researchers have an answer

New insights explain how snakes convert infrared radiation into electrical signals

October 21, 2020

Certain species of snake — think pit vipers, boa constrictors and pythons, among others — are able to find and capture prey with uncanny accuracy, even in total darkness. Now scientists have discovered how these creatures are able to convert the heat from organisms that are warmer than their ambient surroundings into electrical signals, allowing them to “see” in the dark.

The work, published in the journal Matter, provides a new explanation for how that process works, building upon the researchers’ previous work to induce pyroelectric qualities in soft materials, allowing them to generate an electric charge in response to mechanical stress.

Researchers have known electrical activity was likely to be involved in allowing the snakes to detect prey with such exceptional skill, said Pradeep Sharma, M.D. Anderson Chair Professor of mechanical engineering at the University of Houston and corresponding author for the paper. But naturally occurring pyroelectric materials are rare, and they are usually hard and brittle. The cells in the pit organ — a hollow chamber enclosed by a thin membrane, known to play a key role in allowing snakes to detect even small temperature variations — aren’t pyroelectric materials, said Sharma, who also is chairman of the Department of Mechanical Engineering at UH.

But when he and colleagues last year reported producing pyroelectric effects in a soft, rubbery material, something clicked.

“We realized that there is a mystery going on in the snake world,” he said. “Some snakes can see in total darkness. It would be easily explained if the snakes had a pyroelectric material in their bodies, but they do not. We realized that the principle behind the soft material we had modeled probably explains it.”

Not all snakes have the ability to produce a thermal image in the dark. But those with a pit organ are able to use it as an antenna of sorts to detect the infrared radiation emanating from organisms or objects that are warmer than the surrounding atmosphere. They then process the infrared radiation to form a thermal image, although the mechanism by which that happened hasn’t been clear.

Sharma and his colleagues determined that the cells inside the pit organ membrane have the ability to function as a pyroelectric material, drawing upon the electrical voltage that is found in most cells. Through modeling, they used their proposed mechanism to explain previous experimental findings related to the process.

“The fact that these cells can act like a pyroelectric material, that’s the missing connection to explain their vision,” Sharma said.

This work was part of the Ph.D. dissertation of Faezeh Darbaniyan, first author on the paper. Additional researchers on the project include Kosar Mozaffari, a student at UH, and Professor Liping Liu of Rutgers University.

The work explains the mechanism by which the cells are able to take on pyroelectric properties, although questions remain, including how the proposed mechanism is related to the role played by the increased number of ion channels found in TRPA1 proteins. TRPA1 proteins are more abundant in the cells of pit-organ snakes than in non-pit snakes.

“Our mechanism is very robust and simple. It explains quite a lot,” Sharma said. “At the same time, it is undeniable these channels play a role as well, and we are not yet sure of the connection.”

New pterosaur species discovery in Morocco


This 16 October 2020 video, in Vietnamese, is about the discovery of the new pterosaur species Leptostomia begaaensis.

From the University of Portsmouth in England:

Beak bone reveals pterosaur like no other

October 14, 2020

A new species of small pterosaur — similar in size to a turkey — has been discovered, which is unlike any other pterosaur seen before due to its long slender toothless beak.

The fossilised piece of beak was a surprising find and was initially assumed to be part of the fin spine of a fish, but a team of palaeontologists from the universities of Portsmouth and Bath spotted the unusual texture of the bone — seen only in pterosaurs — and realised it was a piece of beak.

Professor David Martill of the University of Portsmouth, who co-authored the study, said: “We’ve never seen anything like this little pterosaur before. The bizarre shape of the beak was so unique, at first the fossils weren’t recognised as a pterosaur.”

Careful searching of the late Cretaceous Kem Kem strata of Morocco, where this particular bone was found, revealed additional fossils of the animal, which led to the team concluding it was a new species with a long, skinny beak, like that of a Kiwi. …

The new species, Leptostomia begaaensis, used its beak to probe dirt and mud for hidden prey, hunting like present-day sandpipers or kiwis to find worms, crustaceans, and perhaps even small hard-shelled clams. …

Dr Nick Longrich, from the Milner Centre for Evolution at the University of Bath, said: “Leptostomia may actually have been a fairly common pterosaur, but it’s so strange — people have probably been finding bits of this beast for years, but we didn’t know what they were until now.”

Long, slender beaks evolved in many modern birds. Those most similar to Leptostomia are probing birds — like sandpipers, kiwis, curlews, ibises and hoopoes. Some of these birds forage in earth for earthworms while others forage along beaches and tidal flats, feeding on bristle worms, fiddler crabs, and small clams.

“Pterosaur fossils typically preserve in watery settings — seas, lakes, and lagoons — because water carries sediments to bury bones. Pterosaurs flying over water to hunt for fish tend to fall in and die, so they’re common as fossils. Pterosaurs hunting along the margins of the water will preserve more rarely, and many from inland habitats may never preserve as fossils at all.

“There’s a similar pattern in birds. If all we had of birds was their fossils, we’d probably think that birds were mostly aquatic things like penguins, puffins, ducks and albatrosses. Even though they’re a minority of the species, their fossil record is a lot better than for land birds like hummingbirds, hawks, and ostriches.”

Over time, more and more species of pterosaurs with diverse lifestyles have been discovered. That trend, the new pterosaur suggests, is likely to continue.

The paper was published today in Cretaceous Research.

Mammal-like reptile discovery in Greenland


A team of scientists led by Grzegorz Nied?wiedzki from Uppsala University have investigated the jaw anatomy and tooth structure of a recently described new mammaliaform species named Kalaallitkigun jenkinsi. Credit: Marta Szubert

From Uppsala University in Sweden:

A tiny jaw from Greenland sheds light on the origin of complex teeth

October 13, 2020

A team of scientists led from Uppsala University have described the earliest known example of dentary bone with two rows of cusps on molars and double-rooted teeth. The new findings offer insight into mammal tooth evolution, particularly the development of double-rooted teeth. The results are published in the scientific journal PNAS.

The first mammals originated in the latest Triassic period, around 205 million years ago. An ancestor to mammals were the therapsids, “mammal-like reptiles” referred to as stem mammals or proto-mammals, which originated about 320-300 million years ago. One unique characteristic of the lineage that included mammals and animals related to mammals (synapsids) was that they developed complex occlusion. Close ancestors to mammals, called mammaliaforms, developed rows of cusps on molar-like teeth adapted for more omnivorous feeding. The origin of this multicusped pattern and double-rooted tooth has thus far remained unclear.

A team of scientists led by Grzegorz Niedzwiedzki from Uppsala University have investigated the jaw anatomy and tooth structure of a recently described new mammaliaform species named Kalaallitkigun jenkinsi. It was discovered on the eastern coast of Greenland and was a very small, shrew-like animal, probably covered with fur. It would have been the size of a large mouse and lived during the Late Triassic, around 215 million years ago.

“I knew it was important from the moment I took this 20 mm specimen off the ground,” says Niedzwiedzki, researcher at Uppsala University and the corresponding author of the publication.

Kalaallitkigun jenkinsi exhibits the earliest known dentary with two rows of cusps on molars and double-rooted teeth. The anatomical features place Kalaallitkigun jenkinsi as an intermediate between the mammals and the insectivorous morganucodontans, another type of mammaliaform.

The researchers believe that the structural changes in the teeth are related to changed feeding habits. In this case study, the animals were switching to a more omnivorous/herbivorous diet and the tooth crown was expanding laterally. Broader teeth with “basins” on the top surface are better for grinding food. This development also forced changes in the structure of the base of the tooth.

The biomechanical analysis that was carried out within the study found that multi-rooted teeth are better able to withstand mechanical stresses, including those of upper and lower tooth contact during biting, compared to single-rooted teeth. Human teeth, for instance, have this characteristic. The results suggest that the development of molar-like teeth with complex crowns may have developed together with biomechanically optimised dual roots.

“The early evolution of mammals is a particularly interesting topic in evolutionary studies. This tiny jaw from Greenland shows us how complex mammalian teeth arose and why they appeared,” says Niedzwiedzki.

“Our discovery of the oldest mammalian ancestor with double-rooted molars shows how important the role of teeth was in the origin of mammals. I had this idea to look at the biomechanics and the collaboration with the engineers turned out great,” says Tomasz Sulej, researcher at the Polish Academy of Sciences, first author of the publication.

“It seems that the fossils of close mammalian ancestors must be looked for in even older rocks,” says Sulej.

Big Money ruining Tyrannosaurus science


This 16 April 2020 video from the USA says about itself:

Mr. Nick talks about Stan, the resident T-rex at the Dinosaur Discovery Museum in Kenosha.

By Michael Greshko in National Geographic, 12 October 2020:

‘Stan’ the T. rex just sold for $31.8 million—and scientists are furious

The fossil was priceless to paleontologists, but experts fear it may be lost to research now that it belongs to an unknown bidder.

More than three decades ago in South Dakota, an amateur paleontologist named Stan Sacrison discovered a titan of the ancient Earth: the fossil of a mostly complete, 39-foot-long Tyrannosaurus rex. Nicknamed “Stan” after its discoverer, the beast was excavated in 1992 and has long been housed at the private Black Hills Institute of Geological Research in Hill City, South Dakota. But even if you’ve never been there, chances are good that you’ve seen this particular T. rex. Dozens of high-quality casts of its bones are on display in museums around the world, from Tokyo to Albuquerque, New Mexico.

Now, an auctioneer’s hammer has thrown Stan’s future into question, with the dinosaur bones sold off to the highest—and, so far, anonymous—bidder, stoking fear among experts that this beloved T. rex may be lost to science.

On October 6, the London-based auction house Christie’s sold the T. rex for a record $31.8 million, the highest price ever paid at auction for a fossil. The previous record was set in 1997 with the sale of “Sue,” a largely complete T. rex dug up by the same South Dakota institute and eventually purchased by the Field Museum of Natural History in Chicago for $8.36 million (equivalent to nearly $13.5 million today).

The day after Stan was sold, paleontologist Lindsay Zanno of the North Carolina Museum of Natural Sciences described the sale price as “simply staggering.”

“That’s an astronomical price that borders on absurdity, based on my knowledge of the market,” added paleontologist David Evans, the vertebrate paleontology chair at the Royal Ontario Museum in Toronto, who suggested the anonymous buyer could have spent the same funds in a far more effective way to deepen humanity’s understanding of the prehistoric beasts. “If this kind of money [were] invested properly, it could easily fund 15 permanent dinosaur research positions, or about 80 full field expeditions per year, in perpetuity,” he wrote in an email interview.

Scientists also have raised concerns about the negative ripple effects the sale could have on the study of dinosaurs by incentivizing people to seek out and sell well-preserved fossils rather than leaving them for paleontologists to study. (Find out more about the U.S. fossil trade in National Geographic magazine.)

“This is terrible for science and is a great boost and incentive for commercial outfits to exploit the dinosaur fossils of the American West,” says tyrannosaur expert Thomas Carr, a paleontologist at Carthage College in Kenosha, Wisconsin.

Paleontologists fear that if the buyer turns out to be a private collector, researchers and the public could lose access to the fossil, limiting their ability to repeat results such as measurements of its bones or conduct new analyses with more advanced tools and techniques. (Find out how scientists are reimaging dinosaurs in today’s “golden age” of paleontology.)

The ability to repeat experiments is “a tenet of science; it’s part of our ethical foundation,” Zanno says. “The paleontological world is holding its breath” to find out Stan’s future. …

For years, the Black Hills Institute had Stan on display in its Hill City museum. In addition to selling resin casts to other museums, the institute gave researchers access to the fossil, resulting in a flurry of scientific papers about everything from T. rex’s immense bite force to how the skull of T. rex could flex and move.

“The skeleton of Stan is without doubt one of the very best Tyrannosaurus rex specimens ever found, and it’s been published in the scientific literature many times,” Evans says. “Stan is one of the keystone specimens for understanding T. rex.”

Carr, for one, included Stan in three studies of tyrannosaur diversity and skull shape earlier in his career. He now regrets that decision because the fossil was always in private hands and therefore at risk of being sold. “In the end, I wound up contributing to the successful sales pitch of the fossil … along with the other 45 scientific publications on Stan,” he says. “We shouldn’t have touched it with a 10-foot pole.”

Stan’s path to the auction block began in 2015, when Neal Larson, a 35-percent shareholder in the Black Hills Institute (and brother of the institute’s president, paleontologist Pete Larson), sued the company to liquidate its assets. According to South Dakota’s Rapid City Journal, the company had removed Neal Larson from its board of directors three years earlier, after a bitter dispute over business dealings and his defense of a former employee accused of sexual misconduct.

A judge ruled in 2018 that Stan had to be auctioned off to pay Neal Larson for his stake in the institute, according to a company press release. …

In the U.S., fossil bones found on federal land are public property and can be collected only by researchers with permits. These remains also must stay in the public trust, in approved repositories such as accredited museums.

However, fossils discovered on U.S. private land can be bought and sold, and Stan isn’t the only U.S. dinosaur fossil recently on the auction block. In 2018, the French auctioneer Arguttes sold off a skeleton of the predatory dinosaur Allosaurus, drawing criticism from scientists because its sale, like Stan’s, risked creating the perception that dinosaurs were worth more in dollars than they were in discoveries.

The 2,000-member Society of Vertebrate Paleontology (SVP), which represents paleontologists around the world, opposes fossil auctions and has long discouraged the study of privately held fossils, out of concern that researchers and the public wouldn’t always be guaranteed access to them.

Jurassic mammals lived more like reptiles


This May 2019 video is called The Mammals that Lived Alongside the Dinosaurs.

From the University of Bristol in England:

Ancient tiny teeth reveal first mammals lived more like reptiles

October 12, 2020

Pioneering analysis of 200 million-year-old teeth belonging to the earliest mammals suggests they functioned like their cold-blooded counterparts — reptiles, leading less active but much longer lives.

The research, led by the University of Bristol, UK and University of Helsinki, Finland, published today in Nature Communications, is the first time palaeontologists have been able to study the physiologies of early fossil mammals directly, and turns on its head what was previously believed about our earliest ancestors.

Fossils of teeth, the size of a pinhead, from two of the earliest mammals, Morganucodon and Kuehneotherium, were scanned for the first time using powerful X-rays, shedding new light on the lifespan and evolution of these small mammals, which roamed the earth alongside early dinosaurs and were believed to be warm-blooded by many scientists. This allowed the team to study growth rings in their tooth sockets, deposited every year like tree rings, which could be counted to tell us how long these animals lived. The results indicated a maximum lifespan of up to 14 years — much older than their similarly sized furry successors such as mice and shrews, which tend to only survive a year or two in the wild.

“We made some amazing and very surprising discoveries. It was thought the key characteristics of mammals, including their warm-bloodedness, evolved at around the same time,” said lead author Dr Elis Newham, Research Associate at the University of Bristol, and previously PhD student at the University of Southampton during the time when this study was conducted.

“By contrast, our findings clearly show that, although they had bigger brains and more advanced behaviour, they didn’t live fast and die young but led a slower-paced, longer life akin to those of small reptiles, like lizards.”

Using advanced imaging technology in this way was the brainchild of Dr Newham’s supervisor Dr Pam Gill, Senior Research Associate at the University of Bristol and Scientific Associate at the Natural History Museum London, who was determined to get to the root of its potential.

“A colleague, one of the co-authors, had a tooth removed and told me they wanted to get it X-rayed, because it can tell all sorts of things about your life history. That got me wondering whether we could do the same to learn more about ancient mammals,” Dr Gill said.

By scanning the fossilised cementum, the material which locks the tooth roots into their socket in the gum and continues growing throughout life, Dr Gill hoped the preservation would be clear enough to determine the mammal’s lifespan.

To test the theory, an ancient tooth specimen belonging to Morganucodon was sent to Dr Ian Corfe, from the University of Helsinki and the Geological Survey of Finland, who scanned it using high-powered Synchrotron X-ray radiation.

“To our delight, although the cementum is only a fraction of a millimetre thick, the image from the scan was so clear the rings could literally be counted,” Dr Corfe said.

It marked the start of a six-year international study, which focused on these first mammals, Morganucodon and Kuehneotherium, known from Jurassic rocks in South Wales, UK, dating back nearly 200 million years.

“The little mammals fell into caves and holes in the rock, where their skeletons, including their teeth, fossilised. Thanks to the incredible preservation of these tiny fragments, we were able to examine hundreds of individuals of a species, giving greater confidence in the results than might be expected from fossils so old,” Dr Corfe added.

The journey saw the researchers take some 200 teeth specimens, provided by the Natural History Museum London and University Museum of Zoology Cambridge, to be scanned at the European Synchrotron Radiation Facility and the Swiss Light Source, among the world’s brightest X-ray light sources, in France and Switzerland, respectively.

In search of an exciting project, Dr Newham took this up for the MSc in Palaeobiology at the University of Bristol, and then a PhD at the University of Southampton.

“I was looking for something big to get my teeth into and this more than fitted the bill. The scanning alone took over a week and we ran 24-hour shifts to get it all done. It was an extraordinary experience, and when the images started coming through, we knew we were onto something,” Dr Newham said.

Dr Newham was the first to analyse the cementum layers and pick up on their huge significance.

“We digitally reconstructed the tooth roots in 3-D and these showed that Morganucodon lived for up to 14 years, and Kuehneotherium for up to nine years. I was dumbfounded as these lifespans were much longer than the one to three years we anticipated for tiny mammals of the same size,” Dr Newham said.

“They were otherwise quite mammal-like in their skeletons, skulls and teeth. They had specialised chewing teeth, relatively large brains and probably had hair, but their long lifespan shows they were living life at more of a reptilian pace than a mammalian one. There is good evidence that the ancestors of mammals began to become increasingly warm-blooded from the Late Permian, more than 270 million years ago, but, even 70 million years later, our ancestors were still functioning more like modern reptiles than mammals”

While their pace-of-life remained reptilian, evidence for an intermediate ability for sustained exercise was found in the bone tissue of these early mammals. As a living tissue, bone contains fat and blood vessels. The diameter of these blood vessels can reveal the maximum possible blood flow available to an animal, critical for activities such as foraging and hunting.

Dr Newham said: “We found that in the thigh bones of Morganucodon, the blood vessels had flow rates a little higher than in lizards of the same size, but much lower than in modern mammals. This suggests these early mammals were active for longer than small reptiles but could not live the energetic lifestyles of living mammals.”

New mosasaur species discovery in Morocco


This 8 October 2020 video is called New species of mosasaur discovered in Morocco, more than 66 MILLION years ago.

From the University of Alberta in Canada:

Paleontologists identify new species of mosasaur

Ancient lizard’s long, crocodile-like snout suggests it carved out a niche in a competitive marine ecosystem

October 7, 2020

A new species of an ancient marine reptile evolved to strike terror into the hearts of the normally safe, fast-swimming fish has been identified by a team of University of Alberta researchers, shedding light on what it took to survive in highly competitive ecosystems.

Gavialimimus almaghribensis, a new type of mosasaur, was catalogued and named by an international research team led by master’s student Catie Strong, who performed the research a year ago as part of an undergrad honours thesis guided by vertebrate paleontologist Michael Caldwell, professor in the Faculty of Science, along with collaborators from the University of Cincinnati and Flinders University.

More than a dozen types of mosasaur — which can reach 17 metres in length and resemble an overgrown komodo dragon — ruled over the marine environment in what is now Morocco at the tail end of the Late Cretaceous period between 72 and 66 million years ago.

What differentiates Strong’s version, however, is that it features a long, narrow snout and interlocking teeth — similar to the crocodilian gharials, a relative of crocodiles and alligators.

Strong said this discovery adds a layer of clarity to a diverse picture seemingly overcrowded with mega-predators all competing for food, space and resources.

“Its long snout reflects that this mosasaur was likely adapted to a specific form of predation, or niche partitioning, within this larger ecosystem.”

Strong explained there is evidence that each species of the giant marine lizard shows adaptations for different prey items or styles of predation.

“For some species, these adaptations can be very prominent, such as the extremely long snout and the interlocking teeth in Gavialimimus, which we hypothesized as helping it to catch rapidly moving prey,” she said.

She added another distinctive species would be Globidens simplex — described last year by the Caldwell lab — which has stout, globular teeth adapted for crushing hard prey like shelled animals.

“Not all of the adaptations in these dozen or so species are this dramatic, and in some cases there may have been some overlap in prey items, but overall there is evidence that there’s been diversification of these species into different niches,” Strong noted.

Alternatively, the main contrasting hypothesis would be a scenario of more direct competition among species. Strong said given the anatomical differences among these mosasaurs, though, the idea of niche partitioning seems more consistent with the anatomy of these various species.

“This does help give another dimension to that diversity and shows how all of these animals living at the same time in the same place were able to branch off and take their own paths through evolution to be able to coexist like that,” she said.

The remains of the G. almaghribensis included a metre-long skull and some isolated bones. There was nothing to explain the cause of death of the specimen, which was uncovered in a phosphate mine in Morocco that is rich in fossils.

Morocco is an incredibly good place to find fossils, especially in these phosphate mines,” Strong said. “Those phosphates themselves reflect sediments that would have been deposited in marine environments, so there are a lot of mosasaurs there.”

New dinosaur species discovered in Mongolia


This 7 October 2020 video is called Newly discovered species of toothless, two-fingered dinosaur thrived more than 68 million years ago.

From the University of Edinburgh in Scotland:

Toothless dino’s lost digits point to spread of parrot-like species

October 6, 2020

A newly discovered species of toothless, two-fingered dinosaur has shed light on how a group of parrot-like animals thrived more than 68 million years ago.

The unusual species had one less finger on each forearm than its close relatives, suggesting an adaptability which enabled the animals to spread during the Late Cretaceous Period, researchers say.

Multiple complete skeletons of the new species were unearthed in the Gobi Desert in Mongolia by a University of Edinburgh-led team.

Named Oksoko avarsan, the feathered, omnivorous creatures grew to around two metres long and had only two functional digits on each forearm. The animals had a large, toothless beak similar to the type seen in species of parrot today.

The remarkably well-preserved fossils provided the first evidence of digit loss in the three-fingered family of dinosaurs known as oviraptors.

The discovery that they could evolve forelimb adaptations suggests the group could alter their diets and lifestyles, and enabled them to diversify and multiply, the team says.

Researchers studied the reduction in size, and eventual loss, of a third finger across the oviraptors’ evolutionary history. The group’s arms and hands changed drastically in tandem with migrations to new geographic areas — specifically to what is now North America and the Gobi Desert.

The team also discovered that Oksoko avarsan — like many other prehistoric species — were social as juveniles. The fossil remains of four young dinosaurs were preserved resting together.

The study, published in the journal Royal Society Open Science, was funded by The Royal Society and the Natural Sciences and Engineering Council of Canada. It also involved researchers from the University of Alberta and Philip J. Currie Dinosaur Museum in Canada, Hokkaido University in Japan, and the Mongolian Academy of Sciences.

Dr Gregory Funston, of the University of Edinburgh’s School of GeoSciences, who led the study, said: “Oksoko avarsan is interesting because the skeletons are very complete and the way they were preserved resting together shows that juveniles roamed together in groups. But more importantly, its two-fingered hand prompted us to look at the way the hand and forelimb changed throughout the evolution of oviraptors — which hadn’t been studied before. This revealed some unexpected trends that are a key piece in the puzzle of why oviraptors were so diverse before the extinction that killed the dinosaurs.”

Did dinosaur age pterosaurs have feathers?


This December 2018 video says about itself:

Feathers might have originated tens of millions of years before we’d thought, and a 3D rendering of ankylosaur nasal passages lends new insight into how they stayed cool.

From the University of Portsmouth in England:

Evidence that prehistoric flying reptiles probably had feathers refuted

September 28, 2020

Summary: Experts have examined the evidence that prehistoric flying reptiles called pterosaurs had feathers and believe they were, in fact, bald.

The debate about when dinosaurs developed feathers has taken a new turn with a paper refuting earlier claims that feathers were also found on dinosaurs’ relatives, the flying reptiles called pterosaurs.

Pterosaur expert Dr David Unwin from the University of Leicester’s Centre for Palaeobiology Research, and Professor Dave Martill, of the University of Portsmouth have examined the evidence that these creatures had feathers and believe they were in fact bald.

They have responded to a suggestion by a group of his colleagues led by Zixiao Yang that some pterosaur fossils show evidence of feather-like branching filaments, ‘protofeathers’, on the animal’s skin.

Dr Yang, from Nanjing University, and colleagues presented their argument in a 2018 paper in the journal Nature Ecology and Evolution. Now Unwin and Martill, have offered an alternative, non-feather explanation for the fossil evidence in the same journal.

While this may seem like academic minutiae, it actually has huge palaeontological implications. Feathered pterosaurs would mean that the very earliest feathers first appeared on an ancestor shared by both pterosaurs and dinosaurs, since it is unlikely that something so complex developed separately in two different groups of animals.

This would mean that the very first feather-like elements evolved at least 80 million years earlier than currently thought. It would also suggest that all dinosaurs started out with feathers, or protofeathers but some groups, such as sauropods, subsequently lost them again — the complete opposite of currently accepted theory.

The evidence rests on tiny, hair-like filaments, less than one-tenth of a millimetre in diameter, which have been identified in about 30 pterosaur fossils. Among these, Yang and colleagues were only able to find just three specimens on which these filaments seem to exhibit a ‘branching structure’ typical of protofeathers.

Unwin and Martill propose that these are not protofeathers at all but tough fibres which form part of the internal structure of the pterosaur’s wing membrane, and that the ‘branching’ effect may simply be the result of these fibres decaying and unravelling.

Dr Unwin said: “The idea of feathered pterosaurs goes back to the nineteenth century but the fossil evidence was then, and still is, very weak. Exceptional claims require exceptional evidence — we have the former, but not the latter.”

Professor Martill noted that either way, palaeontologists will have to carefully reappraise ideas about the ecology of these ancient flying reptiles. He said, “If they really did have feathers, how did that make them look, and did they exhibit the same fantastic variety of colours exhibited by birds. And if they didn’t have feathers, then how did they keep warm at night, what limits did this have on their geographic range, did they stay away from colder northern climes as most reptiles do today. And how did they thermoregulate? The clues are so cryptic, that we are still a long way from working out just how these amazing animals worked.”

The paper “No protofeathers on pterosaurs” is published this week in Nature Ecology and Evolution.