Fossilized Skull Of Half Mammal, Half Reptile May Rewrite History

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Flaviemys purvisi

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30 May 2018, 7:30 am EDT By Aaron Mamiit Tech Times


The discovery of the fossilized skull of a half-mammal and half-reptile creature may rewrite ancient history, specifically regarding the timeline for the breakup of the supercontinent Pangaea.

The important find follows a similar one earlier this year of a dinosaur fossil in Egypt, which also provided scientists with more clues regarding the Pangaea split.

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Scientists found a fossilized skull of a reptile-like mammal underneath the foot of a dinosaur fossil in Utah. The discovery may rewrite ancient history, due to its implications on theories surrounding the supercontinent Pangaea. (Nature)


Scientists Discover Fossilized Skill Of Reptile-Like Mammal

Scientists were uncasting a dinosaur fossil that was excavated in southeastern Utah when they discovered another skull hidden under the foot of the fossilized herbivore.

The fossilized skull, however, did not look like it belonged to a reptile. Upon the inspection of state paleontologist Jim Kirkland, it appeared that the skull belonged to a mammal.

"We've never found a mammal there in these rocks before," said Kirkland, after the discovery was published in the Nature journal. "This one skull turns out to be a complete oddball."

The Importance Of The Half-Mammal, Half-Reptile Skull
The fossilized skull of the reptile-like mammal was unearthed in a rock from the Cretaceous period, from about 145 million to 65 million years ago. The skull itself was 130 million years old, a finding that goes against previous theories on when the supercontinent Pangaea broke up.

The discovery of the fossil likely means that the Pangaea split likely happened more recently than scientists thought. The finding also suggests that a group of reptile-like mammals bridging the transition between reptiles and mammals saw a "burst of evolution" in several continents.

The new species, named the Cifelliodon wahkarmoosuch, is a haramiyid, which are rabbit-like creatures that were present in Eurasia from the Jurassic and Triassic period to the early Cretaceous period, when the land masses had fully broken up. The discovery of the fossilized skull in Utah, however, provides evidence that haramiyids were present in North America at the time, suggesting that the divide of Pangaea continued for about 15 million years later than theorized.

The Cifelliodon is believed to have weighed up to 2.5 pounds, and was about as big as a small hare. It also had teeth that can nip, shear, and crush like those of fruit-eating bats. The Cifelliodon was large for a mammal during its time, since most other mammals were the size of mice.

The new Pangaea breakup theory follows a report from January regarding the gigantic herbivorous dinosaur Mansourasaurus shahinae in the Sahara Desert of Egypt. The discovery of the well-preserved fossil suggested that dinosaurs moved around in Africa and Eurasia even after the movement of continents, and disputed theories that dinosaurs that lived in Africa were completely isolated in the Cretaceous period.
 
Here's another one for you @Foozil ...

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28 May 2018
Sam Blewett - Independent Staff

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A fossil of a microraptor found in Liaoning Province, China, in 2005 ( Spencer Platt/Getty Images )


Dinosaurs had dandruff, newly discovered fossils reveal

Scientists have discovered the first evidence of dinosaur dandruff, according to a new study.

Fossilised skin flakes were found among the feathers of a 125-million-year-old four-winged microraptor.

Their existence confirms that these dinosaurs shed their skin in small patches like modern birds and mammals rather than whole or in large sections.


"This is the only ever reported fossil dandruff of any kind, so far as I am aware," said Professor Mike Benton, one of the authors of the study published in Nature on Friday.

"So, the first from a dinosaur, the oldest and the first from any fossil."

The researchers used an electronic microscope to study feathers from Chinese samples of the microraptor as well as feathered dinosaurs beipiaosaurus and sinornithosaurus, and the primitive bird confuciusornis.

They discovered corneocytes, dead cells that form the skin's outer layer which are very similar to those in modern birds.

"We were originally interested in studying the feathers, and when we were looking at the feathers we kept finding these little white blobs, the stuff was everywhere, it was in between all the feathers," Dr Maria McNamara from University College Cork told BBC News.

"We started wondering if it was a biological feature like fragments of shells, or reptile skin, but it's not consistent with any of those things, the only option left was that it was fragments of the skin that were preserved, and it's identical in structure to the outer part of the skin in modern birds, what we would call dandruff."

Structural differences in the skin flakes imply that these dinosaurs had lower body heat production than modern birds, according to the study.

This suggests that the Cretaceous-era microraptor was not able to fly for long periods, if at all.

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Chris Baynes 2 May 2018

First birds had full set of teeth, prehistoric fossils show
Gull-like creature with 'remarkably dinosaurian jaw' offers new insight into how birds evolved

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Ichthyornis dispar had a beak full of teeth ( Yale University )


Scientists have pieced together the skull of a toothed bird that they say illustrates the pivotal period in history in which dinosaurs transitioned into modern-day avians.

Known as Ichthyornis dispar, the seagull-like creature lived in North America about 86 million years ago and was first discovered in the 1870s.


The species, which prospered along the warm, shallow sea which once divided the continent, drew the attention of 19th century naturalists including Charles Darwin, who said its toothy jaw offered important insights into evolution.

However, for more than a century the only known specimens of the bird’s skull were flattened or fragmented fossils, limiting researchers’ knowledge of the species.

Now, for the first time, a team led by scientists at Bath and Yale universities have produced a clear 3D picture of the bird’s head, using a complete skull discovered in 2014 and two new cranial specimens which laid undiscovered in museum collections for years.

The bird had a surprising blend of dinosaur and avian features, a discovery that researchers said offered new insight into how modern birds developed beaks.

“Right under our noses this whole time was an amazing, transitional bird,” said Yale paleontologist Bhart-Anjan Bhullar. “It has a modern-looking brain along with a remarkably dinosaurian jaw muscle configuration.”


It has long been known that birds evolved from small, feathered dinosaurs.

The earliest known bird-like creatures, such as Archaeopteryx, which lived 150 million years ago, were substantially different from modern avians. Although they had wings, their skulls more closely resembled those of dinosaurs.

Ichthyornis, unlike Archaeopteryx, is thought to have been a strong flier. Its streamlined body was simplified and adapted for flight like modern birds.


“Despite the modernity of its body and wings, it retained almost a full complement of dinosaurian teeth, and it had a strong bite with large, dinosaurian jaw muscles,” said Mr Bhullar. “However, it perceived its world and thought like a bird, with a bird’s enormous eyes and expanded, modern-looking brain.”

While primitive birds such as Confuciusornis, which lived 125 million years ago, had beaks, the small one sported by Ichthyornis is the first known to have modern attributes like a “pincer tip” for grasping, pecking and fine manipulation.

“Its sharp teeth probably would have assisted in holding onto slippery marine prey, while the incipient beak at the tips of its jaws probably would have allowed it to manipulate objects with fine dexterity such as modern birds can do, and preen its feathers,” said University of Bath paleontologist Daniel Field.

Ichthyornis had a two-foot wingspan and probably ate fish and shellfish. It shared the skies with flying reptiles called pterosaurs at a time when dinosaurs dominated the land.

Toothed birds vanished along with the dinosaurs and many other species after an asteroid impact 66 million years ago.


Ichthyornis fossils were first written about by Yale paleontologist Othniel Charles Marsh in the 19th century and were later cited by Darwin as strong support for his theory of evolution.

The Yale and Bath researchers used CT scans to analyse the newly discovered specimens. Their study is published in the journal Nature.

“The fossil record provides our only direct evidence of the evolutionary transformations that have given rise to modern forms,” said Mr Field. “This extraordinary new specimen reveals the surprisingly late retention of dinosaur-like features in the skull of Ichthyornis - one of the closest-known relatives of modern birds from the Age of Reptiles.”
 
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