How oviraptor dinosaur eggs hatched, new research


This 2013 video says about itself:

Oviraptorid Fights to Protect Nest | Planet Dinosaur | BBC Earth

A female Oviraptorid guards her nest from attackers large and small, but can do nothing about the threat of nature itself.

From the University of Bonn in Germany:

Neutron source enables a look inside dino eggs

Did oviraptorid chicks hatch at the same time? Researchers provide presumptive evidence

January 22, 2020

Did the chicks of dinosaurs from the group oviraptorid hatch from their eggs at the same time? This question can be answered by the length and arrangement of the embryo’s bones, which provide information about the stage of development. But how do you look inside fossilized dinosaur eggs? Paleontologists from the University of Bonn used the neutron source of the Technical University of Munich at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. This showed that oviraptorids developed at different speeds in their eggs and that they resemble modern birds in this respect. The results have been published in the journal Integrative Organismal Biology.

Until now, researchers have assumed that the two-legged dinosaurs known as oviraptorids, which lived in Central Asia during the Upper Cretaceous (from 88 to 66 million years), should be placed between modern crocodiles and birds with regard to their reproductive biology. Crocodiles bury their eggs and the offspring hatch at the same time. With birds, however, hatching in the nest often happens at different times.

Together with scientists from Taiwan, Switzerland and the Heinz Maier-Leibnitz Zentrum in Garching, paleontologists from the University of Bonn have now investigated how differently the development of embryos in three 67 million years old oviraptorid egg fossils from the Ganzhou Basin of Jiangxi Province in China had progressed. “Oviraptorid eggs are found relatively frequently in Central Asia, but most of them are removed from the context of their discovery,” says Thomas Engler from the Institute for Geosciences at the University of Bonn. Often it is then no longer discernible whether the eggs are from a single clutch.

Important find in China

“This is different with the fossils we’ve examined: We found a pair of eggs and another egg together embedded in a block of rock,” reports Dr. Tzu-Ruei Yang, who discovered the unusual find during an excavation near the city of Ganzhou in China. This led the researchers to conclude that the 7-inch (18cm) eggs were laid almost at the same time by a female oviraptorid. Yang completed his doctorate at the Institute for Geosciences at the University of Bonn and now works as a researcher at the National Museum of Natural Sciences in Taiwan.

The researchers tried to estimate whether the baby dinosaurs would have hatched at the same time or at different times based on the developmental stage of the embryos in the three eggs. The length of the bones in the egg plays an important role here. “The embryo with comparatively longer bones is more developed,” explains Yang. Another indication is the extent to which the bones are connected to each other. A more strongly connected skeleton suggests a higher developmental stage of the dinosaur embryo.

A look inside the dinosaur egg

But how is it possible to determine the position of bones inside a fossilized dinosaur egg? The paleontologists at the University of Bonn initially tried to do this with the institute’s own X-ray microcomputer tomograph. “Unfortunately, it was not possible to distinguish the bones from the surrounding rock,” says Engler. For this reason, the researchers took the dinosaur eggs to the research neutron source of the Technical University of Munich at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. “The high penetration depth of the neutrons at the NECTAR and ANTARES facilities made it possible to visualize the internal structures,” says Dr. Malgorzata Makowska, who was in charge of measurements and analyses at the MLZ and is now carrying out research at the Swiss neutron source PSI.

The length and position of the embryo bones led the researchers to conclude that the single egg must have been laid earlier than the pair of eggs in the same clutch. However, the embryos of the pair were also at different developmental stages. Thin sections confirm these results. The researchers used these to measure the thickness of the eggshells. The developing embryo absorbs part of the shell because it needs calcium for its growing skeleton. “The more material is removed from the eggshell, the more advanced the embryo’s development,” explains Yang.

On the basis of these indications, the scientists conclude that the reproductive biology of oviraptorids were similar to that of modern birds, whose chicks hatch at different times. The results argue against the strategy of crocodiles or turtles, which all emerge from their eggs at the same time. This has brought the researchers one step closer to the life of the long-extinct oviraptorids, who roamed Central Asia on two legs. “Furthermore, the study shows that exploring fossils with neutrons yields novel scientific results,” says Engler.

Ornithomimosaur, Therizinosaur and Oviraptorosaur dinosaurs


This 22 January 2020 video is called Dinosaurs X: TheropodaOrnithomimosaurs, Therizinosaurs and Oviraptorosaurs.

‘Asteroid, not volcanoes, killed dinosaurs’


This 2016 video says about itself:

How Asteroids Really Killed The Dinosaurs – Part 1 | Last Days of the Dinosaurs

In the clip from Last Days of the Dinosaur, we learn how the asteroids really killed the dinosaurs

Asteroid Day is celebrated every year on the 30th of June.

This 2016 video says about itself:

How Asteroids Really Killed The Dinosaurs – Part 2 | Last Day Of The Dinosaurs

Did you know that if the asteroid that wiped out the dinosaurs from the face of the Earth would have hit another location, they might still be alive? The shallow waters of the Gulf Of Mexico instantly vaporized as the asteroid hit, causing absolute destruction. This was the Last Day Of The Dinosaurs.

From Yale University in the USA:

In death of dinosaurs, it was all about the asteroid — not volcanoes

January 16, 2020

Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers. It was all about the asteroid.

In a break from a number of other recent studies, Yale assistant professor of geology & geophysics Pincelli Hull and her colleagues argue in a new research paper in Science that environmental impacts from massive volcanic eruptions in India in the region known as the Deccan Traps happened well before the Cretaceous-Paleogene extinction event 66 million years ago and therefore did not contribute to the mass extinction.

Most scientists acknowledge that the mass extinction event, also known as K-Pg, occurred after an asteroid slammed into Earth. Some researchers also have focused on the role of volcanoes in K-Pg due to indications that volcanic activity happened around the same time.

“Volcanoes can drive mass extinctions because they release lots of gases, like SO2 and CO2, that can alter the climate and acidify the world,” said Hull, lead author of the new study. “But recent work has focused on the timing of lava eruption rather than gas release.”

To pinpoint the timing of volcanic gas emission, Hull and her colleagues compared global temperature change and the carbon isotopes (an isotope is an atom with a higher or lower number of neutrons than normal) from marine fossils with models of the climatic effect of CO2 release. They concluded that most of the gas release happened well before the asteroid impact — and that the asteroid was the sole driver of extinction.

“Volcanic activity in the late Cretaceous caused a gradual global warming event of about two degrees, but not mass extinction,” said former Yale researcher Michael Henehan, who compiled the temperature records for the study. “A number of species moved toward the North and South poles but moved back well before the asteroid impact.”

Added Hull, “A lot of people have speculated that volcanoes mattered to K-Pg, and we’re saying, ‘No, they didn’t.'”

Recent work on the Deccan Traps, in India, has also pointed to massive eruptions in the immediate aftermath of the K-Pg mass extinction. These results have puzzled scientists because there is no warming event to match. The new study suggests an answer to this puzzle, as well.

“The K-Pg extinction was a mass extinction and this profoundly altered the global carbon cycle,” said Yale postdoctoral associate Donald Penman, the study’s modeler. “Our results show that these changes would allow the ocean to absorb an enormous amount of CO2 on long time scales — perhaps hiding the warming effects of volcanism in the aftermath of the event.”

The International Ocean Discovery Program, the National Science Foundation, and Yale University helped fund the research.

Feathered dinosaurs differed from birds


This 2013 BBC video says about itself:

With its feathered plumage acting as camouflage Sinornithosaurus moves unseen through the treetops. Recent studies suggest Sinornithosaurus was capable of hunting at night as well as delivering a lethal poison in its bite.

From San Diego Natural History Museum in the USA:

New feathered dinosaur shows dinosaurs grew up differently from birds

January 15, 2020

A new species of feathered dinosaur has been discovered in China, and described by American and Chinese authors and published today in the journal The Anatomical Record.

The one-of-a-kind specimen offers a window into what the earth was like 120 million years ago. The fossil preserves feathers and bones that provide new information about how dinosaurs grew and how they differed from birds.

“The new dinosaur fits in with an incredible radiation of feathered, winged animals that are closely related to the origin of birds“, said Dr. Ashley Poust, who analyzed the specimens while he was a student at Montana State University and during his time as a Ph.D. student at University of California, Berkeley. Poust is now postdoctoral researcher at the San Diego Natural History Museum.

“Studying specimens like this not only shows us the sometimes-surprising paths that ancient life has taken, but also allows us to test ideas about how important bird characteristics, including flight, arose in the distant past.”

Scientists named the dinosaur Wulong bohaiensis. Wulong is Chinese for “the dancing dragon” and references the position of the beautifully articulated specimen.

Wulong bohaiensis

About the discovery

The specimen was found more than a decade ago by a farmer in China, in the fossil-rich Jehol Province, and since then has been housed in the collection of The Dalian Natural History Museum in Liaoning, a northeastern Chinese province bordering North Korea and the Yellow Sea. The skeletal bones were analyzed by Poust alongside his advisor Dr. David Varricchio from Montana State University while Poust was a student there.

Larger than a common crow and smaller than a raven, but with a long, bony tail which would have doubled its length, Wulong bohaiensis had a narrow face filled with sharp teeth. Its bones were thin and small, and the animal was covered with feathers, including a wing-like array on both its arms and legs and two long plumes at the end of its tail.

This animal is one of the earliest relatives of Velociraptor, the famous dromaeosaurid theropod dinosaur that lived approximately 75 million years ago. Wulong’s closest well-known relative would have been Microraptor, a genus of small, four-winged paravian dinosaurs.

The discovery is significant not only because it describes a dinosaur that is new to science, but also because it shows connection between birds and dinosaurs.

“The specimen has feathers on its limbs and tail that we associate with adult birds, but it had other features that made us think it was a juvenile,” said Poust. To understand this contradiction, the scientists cut up several bones of the new dinosaur to examine under a microscope. This technique, called bone histology, is becoming a regular part of the paleontology toolbox, but it’s still sometimes difficult to convince museums to let a researcher remove part of a nice skeleton. “Thankfully, our coauthors at the Dalian Natural History Museum were really forward-thinking and allowed us to apply these techniques, not only to Wulong, but also to another dinosaur, a close relative that looked more adult called Sinornithosaurus.”

The bones showed that the new dinosaur was a juvenile. This means that at least some dinosaurs were getting very mature looking feathers well before they were done growing. Birds grow up very fast and often don’t get their adult plumage until well after they are full-sized. Showy feathers, especially those used for mating, are particularly delayed. And yet here was an immature dinosaur with two long feathers extending beyond the tip of the tail.

“Either the young dinosaurs needed these tail feathers for some function we don’t know about, or they were growing their feathers really differently from most living birds,” explained Poust.

An additional surprise came from the second dinosaur the scientists sampled; Sinornithosaurus wasn’t done growing either. The bone tissue was that of an actively growing animal and it lacked an External Fundamental System: a structure on the outside of the bone that vertebrates form when they’re full size. “Here was an animal that was large and had adult looking bones: we thought it was going to be mature, but histology proved that idea wrong. It was older than Wulong, but seems to have been still growing. Researchers need to be really careful about determining whether a specimen is adult or not. Until we learn a lot more, histology is really the most dependable way.”

In spite of these cautions, Poust says there is a lot more to learn about dinosaurs.

“We’re talking about animals that lived twice as long ago as T. rex, so it’s pretty amazing how well preserved they are. It’s really very exciting to see inside these animals for the first time.”

About the Jehol Biota

The area in which the specimen was found is one of the richest fossil deposits in the world. The Jehol biota is known for the incredible variety of animals that were alive at the time. It is also one of the earliest bird-rich environments, where birds, bird-like dinosaurs, and pterosaurs all shared the same habitat.

“There was a lot of flying, gliding, and flapping around these ancient lakes,” says Poust. “As we continue to discover more about the diversity of these small animals it becomes interesting how they all might have fit into the ecosystem.” Other important changes were happening at the same time in the Early Cretaceous, including the spread of flowering plants. “It was an alien world, but with some of the earliest feathers and earliest flowers, it would have been a pretty one.”

‘Nanotyrannus were young Tyrannosaurus rex’


This 2016 video says about itself:

In this video I talk about the most controversial tyrannosaurid, Nanotyrannus. I give the two sides of the story of the Nanotyrannus – Juvenile T. Rex argument so that it is a bit more clear and transparent.

I also talk about the history of Nanotyrannus, how the argument has developed and changed and the perception of current scientists of this argument.

Nanotyrannus lancensis is around 5m long, lived in the Cretaceous Period in North America and had amazing binocular vision and depth perception.

Among the specimens discovered of Nanotyrannus is “Jane” which is considered to be a juvenile T. Rex as evidence shows it was entering the rapid growth stage of large carnivorous dinosaurs.

From the Oklahoma State University Center for Health Sciences in the USA:

Researchers learn more about teen-age T.Rex

How the large predator grew up

January 1, 2020

Summary: A team studied two mid-sized tyrannosaur skeletons and concluded they were in fact teenage T.Rex and not a new pygmy species. They also studied the interior of the leg bones to determine age and how the dinosaurs grew and matured.

Without a doubt, Tyrannosaurus rex is the most famous dinosaur in the world. The 40-foot-long predator with bone crushing teeth inside a five-foot long head are the stuff of legend. Now, a look within the bones of two mid-sized, immature T. rex allow scientists to learn about the tyrant king’s terrible teens as well.

In the early 2000s, the fossil skeletons of two comparatively small T. rex were collected from Carter County, Montana, by Burpee Museum of Natural History in Rockford, Illinois. Nicknamed “Jane” and “Petey”, the tyrannosaurs would have been slightly taller than a draft horse and twice as long.

The team led by Holly Woodward, Ph.D., from Oklahoma State University Center for Health Sciences studied Jane and Petey to better understand T. rex life history.

The study “Growing up Tyrannosaurus rex: histology refutes pygmy ‘Nanotyrannus’ and supports ontogenetic niche partitioning in juvenile Tyrannosaurus” appears in the peer-reviewed journal Science Advances.

Co-authors include Jack Horner, presidential fellow at Chapman University; Nathan Myhrvold, founder and CEO of Intellectual Ventures; Katie Tremaine, graduate student at Montana State University; Scott Williams, paleontology lab and field specialist at Museum of the Rockies; and Lindsay Zanno, division head of paleontology at the North Carolina Museum of Natural Sciences. Supplemental histological work was conducted at the Diane Gabriel Histology Labs at Museum of the Rockies/Montana State University.

“Historically, many museums would collect the biggest, most impressive fossils of a dinosaur species for display and ignore the others,” said Woodward. “The problem is that those smaller fossils may be from younger animals. So, for a long while we’ve had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception.”

The smaller size of Jane and Petey is what make them so incredibly important. Not only can scientists now study how the bones and proportions changed as T. rex matured, but they can also utilize paleohistology — the study of fossil bone microstructure — to learn about juvenile growth rates and ages. Woodward and her team removed thin slices from the leg bones of Jane and Petey and examined them at high magnification.

“To me, it’s always amazing to find that if you have something like a huge fossilized dinosaur bone, it’s fossilized on the microscopic level as well,” Woodward said. “And by comparing these fossilized microstructures to similar features found in modern bone, we know they provide clues to metabolism, growth rate, and age.”

The team determined that the small T. rex were growing as fast as modern-day warm-blooded animals such as mammals and birds. Woodward and her colleagues also found that by counting the annual rings within the bone, much like counting tree rings, Jane and Petey were teenaged T.rex when they died; 13 and 15 years old, respectively.

There had been speculation that the two small skeletons weren’t T. rex at all, but a smaller pygmy relative Nanotyrannus. Study of the bones using histology led the researchers to the conclusion that the skeletons were juvenile T. rex and not a new pygmy species.

Instead, Woodward points out, because it took T. rex up to twenty years to reach adult size, the tyrant king probably underwent drastic changes as it matured. Juveniles such as Jane and Petey were fast, fleet-footed, and had knife-like teeth for cutting, whereas adults were lumbering bone crushers. Not only that, but Woodward’s team discovered that growing T. rex could do a neat trick: if its food source was scarce during a particular year, it just didn’t grow as much. And if food was plentiful, it grew a lot.

“The spacing between annual growth rings record how much an individual grows from one year to the next. The spacing between the rings within Jane, Petey, and even older individuals is inconsistent — some years the spacing is close together, and other years it’s spread apart,” said Woodward.

The research by Woodward and her team writes a new chapter in the early years of the world’s most famous dinosaur, providing evidence that it assumed the crown of tyrant king long before it reached adult size.