In Canada, found the remains of a prehistoric fish with "rudiments" of fingers

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In Canada, found the remains of a prehistoric fish with "rudiments" of fingers
In Canada, found the remains of a prehistoric fish with "rudiments" of fingers
Anonim

In northern Canada, scientists have found the first complete skeleton of an ancient fish, whose front fins were equipped with a set of full-fledged fingers. Scientists described "an intermediate link in evolution" in the scientific journal Nature.

“We found unambiguous evidence that there were fingers inside the rays of the fins of the fish. The knuckles of these rays are very similar to how the bones of the fingers are arranged in most animals. before the fish left the ocean , - said one of its authors, professor at Flinders University (Australia) John Long.

According to modern concepts, lobe-finned fish began to colonize land about 375-370 million years ago, at the end of the Devonian period. The first true amphibians, which can live on land almost permanently, appeared later, approximately 20-30 million years after the fish left the ocean.

How exactly this process took place, while scientists cannot say, since the time of the appearance of transitional forms between amphibians and fish accounts for the so-called "Romer's failure" - a period of time during which the remains of the first amphibians and "fish-animals" are still incomprehensible to for reasons not preserved in the rocks of the Devonian and Carboniferous periods.

Therefore, paleontologists know only about a few bizarre animals of this era, including the primitive amphibians pederpes, watcherias and acanthostegs, as well as the tiktaalik fish. Scientists have found their remains mainly in the last ten years in northern Canada.

Fish with fingers

During excavations in another region of Canada, in the vicinity of Quebec, Long and his colleagues found in rocks about 390 million years old, well-preserved remains of one of the creatures that lived during Romer's failure.

The find was a complete skeleton of Elpistostege watsoni, a close relative of Tiktaalik, the existence of which scientists previously knew only from skull fragments that their colleagues found in the 80s of the last century and at the beginning of the last decade. This time, paleontologists found a complete body imprint of this predatory fish and studied its anatomy in detail, spending about ten years in total.

In general, elpistostega turned out to be very similar to tiktaalik, however, paleontologists found a unique set of bones in its fins that distinguished it from other lobe-finned fish. Long and his colleagues found that the creature's fins contained full-fledged fingers and a sort of hand.

Considering the similarity of the anatomy of Elpistostege watsoni and tiktaalik, scientists suggested that this fish could crawl in shallow waters and stand on fins, keeping its mass with its fingers. This ability, evolutionists have long assumed, was one of the most important innovations that led the ancestors of land vertebrates to colonize land.

'Reconstruction of Remains and Lifestyle Elpistostegy Credit - John Long / Youtube'

Paleontologists conclude that this feature of their find, coupled with similar features in the anatomy of the shoulder and "paws" of Elpistostegs and the first amphibians, such as Acanthostegs and Tulerpetons, makes it the first full-fledged "transitional species" between fish and amphibians.

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