Permian-Triassic extinction survivor discovered in Antarctica


An anomodont skull of Suminia

From BigNews Network:

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

ANI Thursday 3rd December, 2009

Washington: 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.

See also here. And here.

Relationships & Monophyly of Therocephalian Therapsids: here.

An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida): here.

Dr Chen and his team are studying the much delayed recovery of marine species after the ‘Great Dying’, which occured 251 million years ago, by examining fossils around the world, particularly in his native South China, which, during the Triassic, enjoyed a temperate climate and was the site of a major re-flourishing of microfloras, then invertebrates and vertebrates following an order from low to high levels comparable to modern ecosystems: here.

The Permian extinction event was the biggest shake-up of life that Earth has ever seen: in the “Great Dying” that took place 250 million years ago, more than 90 percent of marine species were killed and about 70 percent of land animals vanished. The cause of this catastrophe has been debated for years, but new research suggests that volcanic eruptions triggered massive coal fires that pumped pollution into the air, eventually poisoning the planet: here.

The end-Permian crisis, by far the most dramatic biological crisis to affect life on Earth, was triggered by a number of physical environmental shocks – global warming, acid rain, ocean acidification and ocean anoxia. These were enough to kill off 90 per cent of living things on land and in the sea: here.

Tetraceratops insignis is not a close and nearly unknown relative with 4 horns of the well-known dinosaur Triceratops, but a very ancient mammal-like reptile or sphenacodontid (intermediate between therapsids and pelycosaurs). This classification is still uncertain and controversial among palaeontologists and, consequently, not definitive. In any case, Tetraceratops is considered an early therapsid, maybe the first one and still not completely evolved as such.

Scientists have uncovered a lot about the Earth’s greatest extinction event that took place 250 million years ago when rapid climate change wiped out nearly all marine species and a majority of those on land. Now, they have discovered a new culprit likely involved in the annihilation: an influx of mercury into the eco-system: here.

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6 thoughts on “Permian-Triassic extinction survivor discovered in Antarctica

  1. Pingback: Fossil coelacanth discovery | Dear Kitty. Some blog

  2. Pingback: Antarctic fossil fish discovery | Dear Kitty. Some blog

  3. Pingback: Triassic wildlife after mass extinction | Dear Kitty. Some blog

  4. Pingback: South African Permian fossil discovery | Dear Kitty. Some blog

  5. Pingback: Chinese Permian fossils discoveries | Dear Kitty. Some blog

  6. Pingback: How dinosaurs originated | Dear Kitty. Some blog

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