Oviraptor dinosaurs, not egg thieves


This 16 October 2019 video says about itself:

The Case of the Dinosaur Egg Thief

Paleontologists found a small theropod dinosaur skull right on top of a nest of eggs that were believed to belong to a plant-eating dinosaur. Instead of being the nest robbers that they were originally thought to be, [Oviraptor] raptors like this one would reveal themselves to actually be caring parents.

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Velociraptor relative dinosaur discovery in Canada


This 2009 video says about itself:

Tribute to Saurornitholestes

Saurornitholestes (“lizard-bird thief”) is a genus of coyote-sized carnivorous dromaeosaurid dinosaur from the Upper Cretaceous (Upper Campanian stage) of Alberta, Canada. Several partial skeletons, dozens of isolated bones, and scores of teeth are known from the badlands of Dinosaur Provincial Park in Alberta; most of these are housed at the Royal Tyrrell Museum of Palaeontology, in Drumheller, Alberta.

Like other theropods in the family Dromaeosauridae, Saurornitholestes had a long, curving, blade-like claw on the second toe. Saurornitholestes was more long-legged and lightly built than other dromaeosaurids such as Velociraptor and Dromaeosaurus. It resembles Velociraptor in having large, fanglike teeth in the front of the jaws. Saurornitholestes most closely resembles Velociraptor, although the precise relationships of the Dromaeosauridae are still relatively poorly understood.

Saurornitholestes appears to have been the most common small theropod in Dinosaur Provincial Park, and teeth and bones are much more common than those of its more massive contemporary, Dromaeosaurus. Little is known about what it ate and how it lived, but a tooth of Saurornitholestes has been found embedded in the wing bone of a large pterosaur, probably a juvenile Quetzalcoatlus. Because the pterosaur was so much larger than Saurornitholestes, Currie and Jacobsen suggest that the theropod was probably scavenging the remains of an already dead animal.

Similar teeth are found in younger deposits, but whether they represent S. langstoni or a different, related species is unknown.

From the University of Alberta in Canada:

Paleontologists discover complete Saurornitholestes langstoni specimen

Discovery provides valuable insight into evolution of theropod dinosaurs around the world

October 17, 2019

The discovery of a nearly complete dromaeosaurid Saurornitholestes langstoni specimen is providing critical information for the evolution of theropod dinosaurs, according to new research by a University of Alberta paleontologist.

The 76-million-year-old species was long thought to be so closely related to Velociraptor from Mongolia that some researchers even called it Velociraptor langstoni — until now.

The landmark discovery was made by paleontologists Philip Currie and Clive Coy from the University of Alberta and David Evans, James and Louise Temerty Endowed Chair of Vertebrate Palaeontology at the Royal Ontario Museum. The research illustrates how Saurornitholestes differs from Velociraptor. Importantly, the research also identifies a unique tooth evolved for preening feathers and provides new evidence that the dromaeosaurid lineage from North America that includes Saurornitholestes is distinct from an Asian lineage that includes the famous Velociraptor.

“Palaeontology in general is a gigantic puzzle where most of the pieces are missing. The discovery and description of this specimen represents the recovery of many pieces of the puzzle,” said Currie, professor in the Department of Biological Sciences and Canada Research Chair in Dinosaur Paleobiology. “This ranks in the top discoveries of my career. It is pretty amazing.”

Another piece of the puzzle

Saurornitholestes is a small, feathered carnivorous dinosaur within the dromaeosaurid family (also known as “raptors“) that was previously known from fragmentary remains. Discovered by Coy in Dinosaur Provincial Park in 2014, the new skeleton is remarkably complete and exquisitely preserved, with all the bones (except for the tail) preserved in life position. The new research, which focuses on the skull, shows that the North American form has a shorter and deeper skull than the Velociraptor. At the front of the skull’s mouth, the researchers also discovered a flat tooth with long ridges, which was likely used for preening feathers. The same tooth has since been identified in Velociraptor and other dromaeosaurids.

“Because of their small size and delicate bones, small meat-eating dinosaur skeletons are exceptionally rare in the fossil record. The new skeleton is by far the most complete and best-preserved raptor skeleton ever found in North America. It’s a scientific goldmine,” said Evans.

The study also establishes a distinction between dromaeosaurids in North America and Asia. “The new anatomical information we have clearly shows that the North American dromaeosaurids are a separate lineage from the Asian dromaeosaurids, although they do have a common ancestor,” said Currie. “This changes our understanding of intercontinental movements of these animals and ultimately will help us understand their evolution.”

Future research will investigate the remainder of the skeleton as well as additional analyses on the relationships between dromaeosaurids.

Koolasuchus, big Australian Cretaceous age amphibian


THis 29 September 2019 video says about itself:

Koolasuchus – The Antarctic Amphibian That Ate Dinosaurs

Prehistoric Australia was home to all sorts of strange creatures, including a giant carnivorous amphibian that may have fed on dinosaursKoolasuchus.

How Tyrannosaurus rex bit, new research


This October 2018 video says about itself:

The team working on Saurian have just revealed their massive, year-long project in a blog post; the complete redesigning of their game’s T. rex. And it might be the most accurate Tyrannosaurus anyone’s ever created.

From the University of Missouri-Columbia in the USA:

T. rex used a stiff skull to eat its prey

3D models shows how ligaments and joints in the skull of a Tyrannosaurus rex work

September 25, 2019

A Tyrannosaurus rex could bite hard enough to shatter the bones of its prey. But how it accomplished this feat without breaking its own skull bones has baffled paleontologists. That’s why scientists at the University of Missouri are arguing that the T. rex’s skull was stiff much like the skulls of hyenas and crocodiles, and not flexible like snakes and birds as paleontologists previously thought.

“The T. rex had a skull that’s 6 feet long, 5 feet wide and 4 feet high, and bites with the force of about 6 tons,” said Kaleb Sellers, a graduate student in the MU School of Medicine. “Previous researchers looked at this from a bone-only perspective without taking into account all of the connections — ligaments and cartilage — that really mediate the interactions between the bones.”

Using a combination of imaging, anatomy and engineering analysis, the team observed how the roof of the mouth of the T. rex reacted to the stresses and strains from chewing by applying models of how two present day relatives of T. rex — a gecko and a parrot — chew to how the T. rex skull worked.

“Dinosaurs are like modern-day birds, crocodiles and lizards in that they inherited particular joints in their skulls from fish — ball and socket joints, much like people’s hip joints — that seem to lend themselves, but not always, to movement like in snakes,” said Casey Holliday, an associate professor of anatomy in the MU School of Medicine. “When you put a lot of force on things, there’s a tradeoff between movement and stability. Birds and lizards have more movement but less stability. When we applied their individual movements to the T. rex skull, we saw it did not like being wiggled in ways that the lizard and bird skulls do, which suggests more stiffness.”

In addition to helping paleontologists with a detailed study of the anatomy of fossilized animals, researchers believe their findings can help advance human and animal medicine by providing better models of how joints and ligaments interact.

“In humans, this can also be applied to how people’s jaws work, such as studying how the jaw joint is loaded by stresses and strains during chewing,” said Ian Cost, the lead researcher on the study. Cost is an assistant professor at Albright College and a former doctoral student in the MU School of Medicine. “In animals, understanding how those movements occur and joints are loaded will, for instance, help veterinarians better understand how to treat exotic animals such as parrots, which suffer from arthritis in their faces.”

How mosasaurs swam, new research


This 2013 video says about itself:

Sharks were still prowling the seas during the reign of the dinosaurs and here a mosasaur is on the attack when a group of sharks starts feeding on its young.

From the Geological Society of America in the USA:

Did mosasaurs do the breast stroke?

September 23, 2019

Mosasaurs were true sea monsters of late Cretaceous seas. These marine lizards — related to modern snakes and monitor lizards — grew as long as fifty feet, flashed two rows of sharp teeth, and shredded their victims with enormous, powerful jaws.

Now, new research suggests that mosasaurs had yet another potent advantage: a muscular breast stroke that may have added ambush-worthy bursts of speed.

“We know that mosasaurs most likely used their tails for locomotion. Now we think that they also used their forelimbs, or their tail and forelimbs together,” explains lead author Kiersten Formoso, a Ph.D. student in vertebrate paleontology at the University of Southern California. That dual swimming style, she says, could make mosasaurs unique among tetrapods (four limbed creatures), living or extinct.

Previous studies noted that mosasaurs had an unusually large pectoral girdle — the suite of bones that support the forelimbs. But most assumed the creature’s swimming was mainly driven by their long tails, something like alligators or whales. That smooth, long distance-adapted swimming style is called “cruising”, as opposed to “burst” motion. “Like anything that swims or flies, the laws of fluid dynamics mean that burst versus cruising is a tradeoff,” explains co-author Mike Habib, Assistant Professor of Anatomical Sciences at USC. “Not many animals are good at both.”

To dive in more closely on whether mosasaurs were burst-adapted, cruise-adapted, or an unusual balance of both, Formoso and co-authors focused on the oversized pectoral girdle. They studied a fossil Plotosaurus, a type of mosasaur, at the Natural History Museum of Los Angeles County. In addition, they used measurements of mosasaur pectoral girdles published in other studies.

They determined that the mosasaurs’ unusually large and low-placed pectoral girdle supported large muscle attachments. In addition, says Habib, asymmetry in the bone structure is a telltale sign of the strong, inward pull-down motion called adduction. These analyses suggest that mosasaurs used their forelimbs to swim, breast-stroke style, adding powerful bursts of propulsion to their ability to cruise.

The team continues to model bone structure, morphology, measurements, and fluid dynamics such as drag to learn exactly how, and how fast, these sea monsters swam. Along with applications to biomechanics, and even robotics, say Formoso and Habib, the study also sheds light on how evolution and ecosystems are affected by fluid dynamics.

Formoso points out that it’s a challenge to study kinematics on extinct animals, considering that the subjects are missing flesh, skin, and many bones. But one thing is nearly certain, she says. “Mosasaurs swam unlike anything else.”

Cretaceous era animals, sizes compared


This 19 September 2019 video says about itself:

ANIMALS OF THE CRETACEOUS PERIOD. Size Comparison. Paleoart

FEATURED TAXA: Shuvuuia, Repenomamus, Iberomesornis, Stegoceras, Psittacosaurus, Armadillosuchus, Neimongosaurus, Protoceratops, Citipati, Velociraptor, Nodosaurus, Struthiomimus, Euoplocephalus, Zhenyuanopterus, Kaprosuchus, Chasmosaurus, Koolasuchus, Austroraptor, Regaliceratops, Concavenator, Rajasaurus, Ouranosaurus, Sarcoshuchus, Neovenator, Yutyrannus, Parasaurolophus, Bajadasaurus, Edmontosaurus, Suchomimus, Pteranodon, Tyrannosaurus, Arambourgiania, Dreadnoughtus.

Big pterosaur discovery in Canada


Cryodrakon boreas. Credit David Maas

Artist’s depiction of Cryodrakon boreas, featuring Canadian colours in honour of where the fossils were found. The true colours of the species aren’t actually known. Illustration: Davis Maas

This is artist David Maas’s depiction of Cryodrakon boreas, featuring Canadian colours in honour of where the fossils were found. The true colours of the species aren’t actually known.

From Queen Mary University of London, England:

New flying reptile species was one of largest ever flying animals

September 10, 2019

A newly identified species of pterosaur is among the largest ever flying animals, according to a new study from Queen Mary University of London.

Cryodrakon boreas, from the Azhdarchid group of pterosaurs (often incorrectly called ‘pterodactyls‘), was a flying reptile with a wingspan of up to 10 metres which lived during the Cretaceous period around 77 million years ago.

Its remains were discovered 30 years ago in Alberta, Canada, but palaeontologists had assumed they belonged to an already known species of pterosaur discovered in Texas, USA, named Quetzalcoatlus.

The study, published in the Journal of Vertebrate Paleontology, reveals it is actually a new species and the first pterosaur to be discovered in Canada.

Dr David Hone, lead author of the study from Queen Mary University of London, said: “This is a cool discovery, we knew this animal was here but now we can show it is different to other azhdarchids and so it gets a name.”

Although the remains — consisting of a skeleton that has part of the wings, legs, neck and a rib — were originally assigned to Quetzalcoatlus, study of this and additional material uncovered over the years shows it is a different species in light of the growing understanding of Azhdarchid diversity.

The main skeleton is from a young animal with a wingspan of about 5 metres but one giant neck bone from another specimen suggests an adult animal would have a wingspan of around 10 metres.

This makes Cryodrakon boreas comparable in size to other giant azhdarchids including the Texan Quetzalcoatlus which could reach 10.5 m in wingspan and weighed around 250 kg.

Like other azhdarchids these animals were carnivorous and predominantly predated on small animals which would likely include lizards, mammals and even baby dinosaurs.

Dr Hone added: “It is great that we can identify Cryodrakon as being distinct to Quetzalcoatlus as it means we have a better picture of the diversity and evolution of predatory pterosaurs in North America.”

Unlike most pterosaur groups, Azhdarchids are known primarily from terrestrial settings and, despite their likely capacity to cross oceanic distances in flight, they are broadly considered to be animals that were adapted for, and lived in, inland environments.

Despite their large size and a distribution across North and South America, Asia, Africa and Europe, few azhdarchids are known from more than fragmentary remains. This makes Cryodrakon an important animal since it has very well preserved bones and includes multiple individuals of different sizes.