Herbivorous dinosaurs, new research


This May 2018 video is called 10 LARGEST Herbivorous Dinosaurs That Ever Lived.

From ScienceDaily:

Dull teeth, long skulls, specialized bites evolved in unrelated plant-eating dinosaurs

December 5, 2019

Herbivorous dinosaurs evolved many times during the 180 million-year Mesozoic era, and while they didn’t all evolve to chew, swallow, and digest their food in the same way, a few specific strategies appeared time and time again. An investigation of the skulls of 160 non-avian dinosaurs revealed the evolution of common traits in the skulls and teeth of plant-eating members of otherwise very different families of these extinct reptiles. These new examples of convergent evolution in plant-eating dinosaurs appear December 5 in the journal Current Biology.

“People often think of dinosaurs as a swansong for extinction or that they were a failed species. But they were actually extremely successful in terms of how different species’ anatomies evolved — particularly in herbivores,” says co-senior author David J. Button (@ItsDavidButton), a paleontologist at the Natural History Museum, London.

By looking at herbivorous and carnivorous dinosaur skulls, Button and co-senior author Lindsay Zanno, a professor at North Carolina State University and the head of paleontology at the North Carolina Museum of Natural Sciences, found that while there are many ways for dinosaurs that eat similar foods to evolve, some traits reappear during evolution, even in unrelated species.

Herbivorous dinosaurs came in all shapes and sizes. Some exhibited dull, flat teeth like horses, while others had beaked faces like tortoises; some developed towering necks like giraffes, while others mimicked the short and stout build of a rhino. “Nonetheless, we see the evolution of common traits in the skull between these otherwise very different herbivorous dinosaur groups,” explains Button.

“For example, both the ostrich-like ornithomimosaurs and giant titanosaurs independently evolved elongate skulls and weaker bites, whereas the horned ceratopsians and gazelle-like ornithopods sported more powerful jaws and grinding teeth,” he says. These are results of convergent evolution, where adaptation to a diet of plants led to the evolution of common characters in different dinosaur groups.

The researchers hypothesized that some traits would be most common in plant-eaters. Slow-moving dinosaurs with small heads and dull teeth would likely have a difficult time wrapping their jaws around the neck of another dinosaur, in the way a carnivore like the Tyrannosaurus is thought to have done with ease. Instead, eating plants poses other challenges, such as grinding down tough plant stems.

“There’s a tradeoff between biting speed and biting efficiency,” says Button. “If you’re a herbivorous animal, you don’t really need speed because plants don’t move very fast.”

Some of the results of this functional analysis surprised the researchers, however. That was the case when investigating the eating habits of ankylosaurs, armored, armadillo-like plant-eating dinosaurs with small teeth and a large stomach cavity. Researchers previously thought dinosaurs with these traits usually swallowed their food nearly whole and let their gut break it down. “In our results, we found that ankylosaurs actually may have chewed their food more thoroughly than is often thought. So, that was interesting,” says Button.

In the future, Button and Zanno hope to look at the entire skeleton of herbivorous dinosaurs for similar, reoccurring traits. They also plan to expand this work to better understand predominate traits in carnivores, though Button admits plant-eaters will always be his favorite dinosaurs to study.

“People think that carnivorous dinosaurs are super exciting and cool because they run fast, and kill stuff,” he says. “But I think the plant-eating dinosaurs evolved in much more interesting and sophisticated ways. That’s what makes this work so exciting.”

Brontosaurus dinosaur video


This 1 December 2019 video says about itself:

Brontosaurus – The Story of the Thunder Lizard

The history of Brontosaurus is one of the most fascinating tales in palaeontology, full of controversies, missing heads and charismatic yet unpleasant people.

Styracosaurus dinosaurs, new discovery


This May 2018 video says about itself:

This time, probably the second-most-popular ceratopsid, Styracosaurus–and by extension Rubeosaurus. Hope you’re ready to learn about the environmental and social forces that shaped this giant pig-antelope-bird. …and also what a parietal spike is.

From the University of Alberta in Canada:

Dinosaur skull turns paleontology assumptions on their head

University of Alberta paleontologists uncover spiky skull–and overturn long-standing assumptions in identifying horned dinosaurs

November 25, 2019

A team of researchers at the University of Alberta has unearthed a well-preserved Styracosaurus skull — and its facial imperfections have implications for how paleontologists identify new species of dinosaurs.

The skull was discovered by Scott Persons in 2015, then a graduate student in the Department of Biological Sciences, during an expedition in the badlands northwest of Dinosaur Provincial Park.

Nicknamed Hannah, the dinosaur was a Styracosaurus — a horned dinosaur over five metres in length with a fan of long horns. UAlberta paleontologists led by Robert Holmes, professor in the Department of Biological Sciences, have learned much from those horns — because they aren’t symmetrical.

“When parts of one side of the skull were missing, paleontologists have assumed that the missing side was symmetrical to the one that was preserved,” explained Persons. “Turns out, it isn’t necessarily. Today, deer often have left and right antlers that are different in terms of their branching patterns. Hannah shows dramatically that dinosaurs could be the same way.”

The differences in the skull’s left and right halves are so extreme that had the paleontologists found only isolated halves, they might have concluded that they belong to two different species

“The skull shows how much morphological variability there was in the genus,” said Holmes. Like the antlers of modern deer and moose, Hannah shows that the pattern of dinosaur horns could vary significantly — meaning some fossils that were once assumed to be unique species will have to be reevaluated.

Tradition dictates that the person who finds an important dinosaur specimen gets to give it a nickname. “Hannah the dinosaur is named after my dog,” explained Persons, now a professor and museum curator at the College of Charleston. “She’s a good dog, and I knew she was home missing me while I was away on the expedition.”

Despite the nickname, paleontologists have no way of knowing if the dinosaur was female. But they have learned other details from the skull — from a partnership with researchers in the Faculty of Engineering.

“Ahmed Qureshi and graduate student Baltej Rupal in the Faculty of Engineering assisted us in performing a 3D laser scan of the skull,” said Persons. “That let our publication to include a digital reconstruction, allowing scientists all over the world to download the 3D model and inspect it in detail.”

“This is the future of paleontological collections: digital dinosaurs.”

Did dinosaurs need feathers to fly?


This 18 November 2019 video from the Natural History Museum in London, England says about itself:

Did dinosaurs need feathers to fly?

First found in 2017, Ambopteryx had unusual wings when compared to those of the more commonly known winged species, Archaeopteryx.

Feathered polar dinosaurs discovery in Australia


This 2017 video says about itself:

Over the past 20 years, dinosaurs of all types and sizes have been found with some sort of fluff or even full-on plumage. These fuzzy discoveries have raised a whole batch of new questions so we’re here to tell you everything we know about dinosaurs and feathers.

From Uppsala University in Sweden:

First evidence of feathered polar dinosaurs found in Australia

November 12, 2019

A cache of 118 million-year-old fossilized dinosaur and bird feathers has been recovered from an ancient lake deposit that once lay beyond the southern polar circle.

Feathered dinosaur fossils are famous, but known from a handful of localities worldwide. Examples from the Southern Hemisphere are especially rare, and mainly include only isolated feathers.

An international team of scientists has analyzed a collection of 10 such fossil feathers found in Australia, which reveal an unexpected diversity of tufted hair-like ‘proto-feathers’ from meat-eating dinosaurs, together with downy body feathers, and wing feathers from primitive birds that would have been used for flight.

Uniquely, the fossil feathers from Australia were all entombed in fine muddy sediments that accumulated at the bottom of a shallow lake close to the South Pole during the Age of Dinosaurs.

“Dinosaur skeletons and even the fragile bones of early birds have been found at ancient high-latitudes before. Yet, to date, no directly attributable integumentary remains have been discovered to show that dinosaurs used feathers to survive in extreme polar habitats,” said Dr Benjamin Kear from Uppsala University in Sweden, a leading author on the study.

“These Australian fossil feathers are therefore highly significant because they came from dinosaurs and small birds that were living in a seasonally very cold environment with months of polar darkness every year.”

The fossil feathers were discovered in the Koonwarra Fish Beds Geological Reserve, which is a heritage-listed site 145 km southeast of Melbourne in Victoria, Australia.

“Fossil feathers have been known from Koonwarra since the early 1960s, and were recognized as evidence of ancient birds, but have otherwise received very little scientific attention. Our study is thus the first to comprehensively document these remains, which include new specimens that were examined using cutting-edge technologies,” said Dr Thomas Rich of the Melbourne Museum in Australia, who has led numerous expeditions to the Koonwarra locality.

A suite of advanced microscopic and spectroscopic techniques was employed to determine the anatomy and preservation of the Koonwarra fossil dinosaur and bird feathers.

“The Koonwarra feathers are preserved in incredible detail,” said fossil bird expert Professor Patricia Vickers-Rich of Monash University and the Swinburne University of Technology in Melbourne.

“There are even tiny filament-like structures that would have ‘zipped’ the feather vanes together, just as in the flight feathers of modern birds.”

However, unlike the structurally complex feathers of birds today, which are characterized by interlocking branches called barbs and barbules, different kinds of small dinosaurs had coverings that comprised much more simpler hair-like ‘proto-feathers’.

“Dinosaur ‘proto-feathers’ would have been used for insulation,” said Dr Martin Kundrát, of Pavol Jozef Safarik University in Slovakia, a leading author on the study.

“The discovery of ‘proto-feathers’ at Koonwarra therefore suggests that fluffy feather coats might have helped small dinosaurs keep warm in ancient polar habitats.”

Microscopic remains of possible melanosomes, cellular structures that contain colour pigments, were also detected on several of the fossil feathers found at Koonwarra.

These traces occurred across the uniformly dark feather surfaces, as well as in distinct bands that might represent original patterning from the polar dinosaurs and birds.

Melanic residues have been reported on fossil feathers from elsewhere around the world, and are widely acknowledged as indicators of dinosaur colouration.

The densely packed fossil melanosomes occurring on the Koonwarra feathers could suggest dark colours that perhaps assisted in camouflage, visual communication, and/or heat absorbance in cold polar climates.

Possible preservation of biomolecules was also assessed, but proved to be too degraded, and were apparently lost during weathering of the rock.

The Koonwarra fossil feathers provide the first record of dinosaur integument from the ancient polar regions, and hint what was once a global distribution of feathered dinosaurs and early birds.

Some of the fossil feathers found at Koonwarra are on display in the ‘600 Million Years’ exhibition at the Melbourne Museum in Australia.