Tuesday, January 31, 2017

The oldest ancestor of humans was similar to toothy “bag” – RIA Novosti

31.01.2017

(updated: )

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MOSCOW, 31 Jan — RIA Novosti. Paleontologists have found in China the remains of primitive multi-celled creatures, similar to the kind of toothy “bags”. These creatures claim to be the oldest ancestors of man, vertebrates and sea urchins, according to a paper published in the journal Nature.

“In the past we have been able to find many fossils, the most ancient eras of life on Earth, including the remains of the earliest fish and other animals vtorichnaya. The discovery of fossil organisms Saccorhytus allowed to look at the very first stage of evolution of that group of animals which gave birth to fish and eventually us,” said Shu Degan (Degan Shu) from northwestern University in XI’an (China).

Most modern bands and types of animals came about 540-520 million years ago in the era of the so-called Cambrian explosion — the rapid acceleration of evolution and increasing diversity of multicellular creatures. At this time there appeared the ancestors of worms, insects, fish and other vertebrates.

the Ancestors of humans, land animals and fish are considered vtorichnaya animals, the most primitive representatives of which are sea stars and sea urchins. Other multicellular organisms — insects, worms, and shellfish are among PERVICHNAYA animals.

© Photo: Museum of paleontology Orlov

the Main difference from vtorichnaya PERVICHNAYA is that with the development of the embryo in their mouth and anal hole, figuratively speaking, are reversed. Embryonic mouth becomes anus, and a new mouth is formed at the opposite end of the embryo. Scientists have long been interested in how there was such a permutation.

Shu and his colleagues found a possible answer to this question, by studying the unusual deposits of oil shale in Shanxi province. These rocks were formed during the Cambrian explosion (circa 520-510 million years ago) on the territory of modern China. They were formed at the bottom of the primary ocean of the Earth with almost no oxygen, so they still keep the prints of even the soft tissues of the bodies of ancient animals.

Exploring these deposits, Chinese and American paleontologists found the remains of an unusual animal — a small oval structure with a length of one millimeter, similar to a bag with a “toothy” edges. It was named Saccorhytus coronarius, which translates from Latin as “wrinkled bag with the crown.”

As said Shu, his team had to “sift” about three tons of rocks since the first of the remains Saccorhytus coronarius in order to find the complete remains and to understand which group of animals do these creatures belong to.

the scientists ‘ Interest was caused by the fact that they could not understand where is the anus of this creature. After analyzing several dozen fossils, Shu and his colleagues came to the conclusion that Saccorhytus coronarius. This suggests that paleontologists managed to find the oldest animal voicenote.

© Photo: Danielle Dufault

These organisms, as scientists assume, had something like gills, traces of which can be seen in the form of conical structures on his skin. Through them “the bag” let the water which is swallowed with food. Subsequently, these cones could turn into the Gill arch and then to the jaw and nose of the first fish marking the beginning of human evolution, which will appear on Earth through 519,8 million years after hitting “toothy bags” in shale of Cambrian annals.

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