Antarctica may have served as climatic refuge in Earth's greatest extinction event

Washington, December 3 (ANI): A new fossil species suggests that some land animals may have survived Earth's greatest extinction event, about 252 million years ago, by taking refuge in cooler climates in Antarctica.

Jorg Frobisch and Kenneth D. Angielczyk of The Field Museum together with Christian A. Sidor from the University of Washington have identified a distant relative of mammals, Kombuisia antarctica, that apparently survived the mass extinction at the end of the Permian Period by living in Antarctica.

The new species belongs to a larger group of extinct mammal relatives, called anomodonts, which were widespread and represented the dominant plant eaters of their time.

"Members of the group burrowed in the ground, walked the surface and lived in trees," said Frobisch, the lead author of the study.

Kombuisia antarctica was not a direct ancestor of living mammals, but it was among the few lineages of animals that survived at a time when a majority of life forms perished.

When it served as refuge, Antarctica was located some distance north of its present location, was warmer and wasn't covered with permanent glaciers, according to the researchers.

The refuge of Kombuisia in Antarctica probably wasn't the result of a seasonal migration but rather a longer-term change that saw the animal's habitat shift southward.

Fossil evidence suggests that small and medium sized animals were more successful at surviving the mass extinction than larger animals.

They may have engaged in "sleep-or-hide" behaviors like hibernation, torpor and burrowing to survive in a difficult environment.

Earlier work by Fröbisch predicted that animals like Kombuisia antarctica should have existed at this time, based on fossils found in South Africa later in the Triassic Period that were relatives of the animals that lived in Antarctica.

"The new discovery fills a gap in the fossil record and contributes to a better understanding of vertebrate survival during the end-Permian mass extinction from a geographic as well as an ecological point of view," Frobisch said.

The team found the fossils of the new species among specimens collected more than three decades ago from Antarctica that are part of a collection at the American Museum of Natural History. (ANI)