Scientists accidentally discovered the «missing link» between fish and amphibians

© Photo : University of Chicago, Neil ShubinТак could look ancient fish tiktaalik in the view of Neil ShubinScientists accidentally discovered the «missing link» between fish and amphibians© Photo : University of Chicago, Neil Shubin

. Paleontologists accidentally discovered a possible «lost link» between fish and land animals, and found that the first inhabitants of the land were like a kind of cross between snakes and fish, according to a paper published in the journal Nature.

«This discovery forces us to radically rethink what they can achieve evolution in the development of early four-legged creatures. We used to think that the transformation of fins into limbs has been very gradual and slow. Our finding shows that this change was dramatic and almost instantaneous, and some early tetrapods lost their legs almost immediately after their purchase,» says Jason Anderson (Jason Anderson) from the University of calgary (Canada).

Today scientists believe that the earliest human ancestors, the lobe-finned fish left the primary ocean of the Earth and started to colonize the land about 375-370 million years ago in the late Devonian period. The first true amphibians creatures appeared much later, approximately 20-30 million years after fish on dry land.

How exactly was this process, no one knows, as this time is, in fact, a giant white spot for paleontologists, which they call the «failure of the Romer». Remains of the earliest amphibians, and «fish animals», yet for reasons unknown to us, is not preserved in rocks of the time. We are aware of only a few examples of bizarre creatures of this transitional era, such as pederpes, watchery and acanthostega and fish tiktaalik, the remains of which were found mostly in the last ten years.

Anderson and his colleagues re-opened another unusual fossil, which, as stated by the scientists themselves, in fact completely negates the idea of the evolution of limbs, which was developed in the study tiktaalik, acanthostega and other «amphibians» of Devon.

This revelation came to the scientists almost by accident. They studied the remains of ancient amphibians Lethiscus stocki, who belonged to the so-called aistopoda – amphibians, like its anatomy and way of life on the sea serpent that lived in the seas of the Earth in the Carboniferous and Permian periods. Unlike other primitive amphibians, they have no limbs and they moved on land and in water, bending his long body.

The remains of Lethiscus stocki was opened in Scotland over 60 years ago, and they have not attracted the attention of scientists, because they remained bad enough, and paleontologists were not able to understand how it was arranged skull and some other body parts of these creatures.

Team Anderson has filled this gap, to educate the remains of Lethiscus stocki using computed tomography and reconstructed three-dimensional shape of the skull, jaws and other body parts of this «amphibious».

Much to the surprise of paleontologists, Lethiscus stocki from the inside has been nothing like his alleged relatives – it was much more obvious and more like a fish than an amphibian.

After analyzing all of the unusual features of these animals and comparing them with the appearance of pederpes, tiktaalik and other ancient «pioneers» of development land, scientists concluded that the discovery of Scotland is actually not aistopoda, and the «missing link» in the evolution of land animals or his next of kin.

The existence of such snake-like creatures in this era, according to Anderson, says that the history of the evolution of the legs and the transition to a terrestrial lifestyle was not as simple as previously thought, and could simultaneously go our separate ways. In addition, it is not excluded that the legs can some times appear and disappear during the early evolution of amphibians.