Strange creature appears to rewrite dinosaur history

(NLDO) - A previously unknown creature has appeared inexplicably in 230 million year old rocks in Wyoming, USA.

According to Sci-News, until now, it was thought that the first creatures that could be called dinosaurs originated in the high latitudes of the ancient supercontinent Gondwana.

During the Triassic period - which began about 251 million years ago - Earth had only two supercontinents, Gondwana in the south and Laurasia in the north. By the middle of this geological period, the earliest dinosaurs began to appear in Gondwana, which were small in size.

By the next geological period, the Jurassic (200-146 million years ago), the dinosaur lineage flourished and entered its heyday in the Cretaceous (145-66 million years ago).

Excavation site in Wyoming (large image) and graphic image depicting the newly excavated creature - Photo: University of Wisconsin Geological Museum

In the northern supercontinent Laurasia, dinosaurs are thought to have appeared at least 6–10 million years after the oldest southern dinosaurs.

But fossil fragments belonging to a mysterious creature found in Wyoning, USA, part of ancient Laurasia, date back 230 million years, contemporaneous with the oldest Gondwana dinosaurs.

This new species was named Ahvaytum bahndooiveche.

"Ahvaytum bahndooiveche lived in Laurasia during or shortly after a major period of climate change called the 'Carnian epoch', which is thought to have been associated with the early diversification of dinosaurs," said Dr Dave Lovelace from the University of Wisconsin Museum of Geology.

The climate during that period was much wetter than before, turning the vast, hot deserts into more favorable habitats for the first dinosaurs.

With the appearance of Ahvaytum bahndooiveche, the history of this beastly family needs to be rewritten: It is clear that simultaneous events took place in both the North and South supercontinents, rather than dinosaurs forming in the South and then migrating north.

Ahvaytum bahndooiveche caused a second shock when analysis results showed that it was a Sauropodomorph, an intermediate group of dinosaurs, the predecessor of the super monster family Sauropod, or giant lizard-footed dinosaurs.

Contrary to expectations, this ancient Sauropodomorph was small, only 1 meter long, very slender and had a tail longer than its neck. Dr. Lovelace described it as "a chicken with a very long tail".

It was nothing like its Sauropod descendants, which could weigh tens of tons, had four legs as big as pillars, a massive body, a characteristic long neck, and a long but very large and heavy tail.

These data also help fill an important gap in the early record of sauropodomorph evolution, according to the paper published in the scientific journal Zoological Journal of the Linnean Society.

“With these fossils, we have the oldest intermediate dinosaur in the world, which is also the oldest dinosaur in North America,” said Dr. Lovelace.

At the same Garrett's Surprise site, paleontologists also found a fossilized bone of a dinosaur-like creature called a silesaurid, suggesting that Wyoming may provide additional interesting pieces to rewrite the early history of dinosaurs.

Source: https://nld.com.vn/my-xuat-hien-sinh-vat-ky-la-viet-lai-lich-su-loai-khung-long-196250110112549942.htm