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Rare fossils from a triassic reptile found in Antarctica



Description of the artist Antarctanax shackleton (left). On the other side of the stream, a large archhozur goes to two unsuspecting dyskinodons.
Image: Adrien Strup, Field Museum

In the most unusual places, fossilized remains of an early reptile of 250 million years have been discovered: Antarctica, the discovery shows how wildlife has recovered after the worst mass extinction in history on our planet and how Antarctica once hosted the ecosystem unlike any other.

It is unnecessary to say that paleontological work in Antarctica is much different than elsewhere. Unlike Alberta or Montana, for example, with an abundance of rocks, Antarctica is covered with a massive ice sheet that covers much of its paleontological history. And it is not as if Antarctica has no stories to tell ̵

1; much. Only in the last 30-35 million years the continent has frozen. Previously, it was home to a warm climate, lush forests, fast rivers and a remarkable abundance of life.

In order to discover the fossilized traces of this forgotten life, whether in Antarctica or elsewhere, scientists have to find rocks. Antarctica provides only two options: coastal islands and central transantarctic mountains – a backbone of mountains crossing Wednesday in the middle of the continent. The tops of these mountains descend through the glaciers, creating a rocky archipelago – a place where paleontologists can do research. This is here, the Fremouw Formation of the Transantrant Mountains, Brandon Peecook, a Paleontologist with the Field History Museum and the lead author of the new study, discovered the rare Triassic Reptilian. It's hard to imagine how alien Antarctica really looked like then, "Pickup said. "Looking around, I did not see any traces of macroscopic life for miles in any direction."

Brandon Peakuk looks for Antarctica.
Image: Roger Smith

Indeed, Antarctica may be desolate and inhospitable today, but it has not always been so. Hundreds of millions of years ago, in the Fremou formation, there lived a lush, lush forest full of life from winged insects to four-reptilian reptilians. The discovery of an unknown iguana reptile now called Antarctanax shackletoni now complements our knowledge of the former ecological glory of the continent. Antarctic means "Antarctic King" and shackletoni is the tip of the cap of British polar Ernest Shackleton. A. Schactleton is an archivist sharing a common ancestor with dinosaurs and crocodiles, and living in the early Triassic period about 250 million years ago. It is now one of the earliest lizards that appear in the fossil record. Details of this discovery were published today in the Journal of Vertebrate Paleontology. The partial fossil consists of perfectly preserved vertebrae (including the neck and back), a partial skull, two legs, several ribs and upper arm bone. It was discovered during an Fremmo expedition during the 2010-2011 Antarctic Summer. The analysis of these fossilized bones (especially the skull) and the fossils found with it implies that it was a pinnacle predator chewing bugs, amphibians and early proto-mammals. Roger Smith of the University of Witwatersrand in South Africa and Christian Sidor of the University of Washington in Seattle helped Peecook in the analysis. One side of the fossil, showing the vertebrae and bone of the hand.

The early trias is of great interest to paleontologists because it has come as a result of one of the worst episodes in the history of the Earth – the ultimate Permanent mass extinction, a time when extreme and the prolonged volcanism destroyed almost 90% of our planet's life. As a result, the ecological reboot has become a scene in which survivors can absorb. Among these survivors are the archaeologists who have taken full advantage of it.

"The pattern that we see again and again with mass disruption such as the ultimate Permian mass extinction is that some of the animals that survived quickly filled the empty sails. Pickup said. – Archosazures are a great example – a group of animals that can do everything in common.

The opposite side of the fossil, showing several vertebrae, ribs and right leg.
Image: Brandon Peakkick, Field Museum

Indeed, the archaeologists, including the dinosaurs, were among the greatest beneficiaries of this recovery period, experiencing immense growth and diversity. Before the mass extinction, these creatures were confined to equatorial regions, but then they were "everywhere," according to Peecook – including, as we already know, Antarctica. The continent was home to A. Shackleton about 10 million years before the appearance of true dinosaurs. As a country, Antarctica hosted dinosaurs, but not until the Jurassic period.

This discovery also sheds light on the distinctive Antarctic animals. Since Antarctica and South Africa were physically connected at that time, paleontologists work on the assumption that the two regions have much to do with local wildlife. And since there are plenty of fossils in South Africa, paleontologists have used this record to draw conclusions about life that probably exists in Antarctica. But, as Pickock explained, it turns out to be a mistake; Antarctica hosted an ecology that did not look like any other.

"We know the records of South Africa, but in Antarctica we've only found about 200 species," he said. "But we do not find these species anywhere else. Paleontologists have gone to Antarctica only a few times, but every time they go, discover new types and surprising new events – it's really exciting. The initial argument that you can link these two environments together is now wrong. Recordings in Antarctica have many unique things that happen. "

Antarctica has a unique set of species, which is not surprising. Like today, the continent was at high altitude, with long days in the summer and long nights in the winter. Animals and plants had to adapt to survive, thus adopting new physical characteristics and survival strategies.

The mind is confronted with the thought of all unknown and unattainable fossils trapped under the Antarctic ice. As Peecook says, he has the paleontological record of the once truly alien environment.

[Journal of Vertebrate Paleontology]


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