South African fossils rewrite life on land

WASHINGTON: Fossils of two amphibians that lived within the Antarctic circle 360 million years ago are forcing scientists to rethink the origins of land vertebrates, including where these pioneers first appeared and the climatic conditions that spawned them.

Scientists said yesterday they had unearthed partial remains of primitive Devonian Period amphibians named Tutusius umlambo and Umzantsia amazana at Waterloo Farm near Grahamstown, South Africa.

While the fossils are frag- mentary, the researchers said Tutusius and Umzantsia most likely shared the four-legged, alligator- crossed- with- a- fish body plan of the earliest amphibians, eating small fish while in the water and perhaps small invertebrates on land.

Umzantsia was about 70cm long with a long, slender lower jaw, apparently armed with small pointed teeth.

Tutusius was about one metre long. It was named in honour of South African Anglican cleric and human rights activist Desmond Tutu.

They were among the early wave of tetrapods, a group including all land-living vertebrates. The first tetrapods evolved from fish during the Devonian. Until now, it had been thought that this evolution revolution occurred in warm climes because the fossils of all the earliest-known amphibians, had been found in places that were tropical or subtropical at the time.

Africa during the Devonian was part of a super-continent called Gondwana that also encompassed South America, India, Australia and Antarctica. The Waterloo Farm site was within the Arctic circle.

“So we now know that tetrapods, by the end of the Devonian, lived all over the world, from the tropics to the Antarctic circle,” said paleontologist Robert Gess, based at the Albany Museum in Grahamstown as part of the South African Centre of Excellence in Palaeosciences, centered at the University of the Witwatersrand. “So it’s possible that they originated anywhere and that they could have moved onto land anywhere. It really broadens the scope of possibilities,” Gess added. – Reuters

PICTURE: REUTERS Two newlydiscovered early amphibians, Tutusius and Umzantsia, which lived about 360 million years ago during the Devonian Period. Their partial remains were unearthed at the Waterloo Farm site in Grahamstown and are shown in this artist’s illustration,...