SA fossils rewrite early history of life on land

Mindy Sparks
June 12, 2018

Although Waterloo Farm wasn't frozen back in the ancient Devonian period-which stretched from 420 to 360 million years ago-it still faced nights that lasted for weeks in the dead of winter.

Twelve Devonian tetrapods have previously been described, all of which came from the Devonian tropics, between 30 degrees north and south of the equator. Ahlberg is one of the authors of a study of the fossils published Friday in the journal Science.

Robert Gess, a paleontologist at the Albany Museum in Grahamstown, said in a statement, "So we now know that tetrapods, by the end of the Devonian, lived all over the world, from the tropics to the Antarctic Circle". But recently discovered fossils provide new details on the origin of four-legged vertebrates and reveal that they were not restricted to warm environments. It is noted that the area in which were found the fossils was at the Antarctic polar circle.

Until now nearly all of the sparse records of Devonian tetrapods came from the other large Devonian continent, Laurussia, which comprised what is now North America, Greenland and Europe.

Until now, all known fossils of Devonian tetrapods or four-legged vertebrates came from wet tropical forests or swamps. The find also calls into question previous theories about where tetrapods evolved and lived. "This discovery totally disrupts this view", Gess said. Taking this into account, it's highly possible that they originated anywhere in the world.

At the Waterloo Farm, near Grahamstown, in South Africa, researchers discovered fossilized remains of two primitive amphibians, Tutusius umlambo and Umzantsia amazana, which inhabited the Devonian Period 360 million years ago. Tutusis is named in honour of Archbishop Desmond Tutu, while Umzantsia reflects its South African heritage.

Tutusius is represented by a single bone from the shoulder girdle‚ whereas Umzantsia is known from a greater number of bones‚ but they both appear similar to previously known Devonian tetrapods.

Although the fossils are incomplete, alive these creatures would have resembled a cross between a crocodile and a fish, sporting a crocodile like head, stubby legs and a tail with a fish-like fin. Scientists found them at the Waterloo Farm that is Grahamstown, South Africa. This cutting exposed dark grey mudstones of the Witpoort Formation that represent an ancient environment of a brackish, tidal river estuary that contain abundant fossils of animals and plants.

The Minister added that it also provided answers as to what occurred before humans existed, including the evolution of plant and animal life, noting that this latest discovery placed South Africa at the forefront of the study of the evolution of land-living vertebrate animals, including the ancestry of all the wildlife in the country's game parks. The research was supported by the South African DST-NRF Centre of Excellence in Palaeosciences, based at the University of the Witwatersrand and the Millennium Trust.

Other reports by Iphone Fresh

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