“The more we discover about prehistoric Antarctica, the stranger it is…”
Barely the size of an iguana, the fossilized remains of a reptile recently discovered in Antarctica suggests that some 250 million years ago, the icy frozen continent was covered with forests and rivers, and the temperature rarely dropped below zero.
The region is thought to have been home to diverse forms of life, including early relatives of the dinosaurs.
The Antarctic King
It was a haven for life, and it was teeming with it. Scientists now report they’ve found an iguana-sized reptile whose name means ‘Antarctic king.’
“This new animal was an archosaur, an early relative of crocodiles and dinosaurs,” explains Brandon Peecook, a Field Museum researcher and lead author of a paper in the Journal of Vertebrate Paleontology describing the new species.
“On its own, it just looks a little like a lizard, but evolutionarily, it’s one of the first members of that big group. It tells us how dinosaurs and their closest relatives evolved and spread.”
The new study reports that the fossil of the so-called Antarctic King is incomplete, but paleontologists believe they have a very good impression of the animal, which they have called Antarctanax shackletoni (the former means ‘Antarctic king,’ the latter is a nod to polar explorer Ernest Shackleton).
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Getting down to details
Based on their similarities to other animal fossils, Peecook and his team believe that the Antarctanax was a carnivore measuring around 1.2 to 1.5 meters long. The Antarctic King is believed to have survived by hunting insects and ancient relatives of mammals and amphibians.
Subtle features in the bones of the spine and the limbs of the lizard, meanwhile, suggest that it was by then a new species, and the shape of its legs suggests that it lived on the ground.
However, experts note that perhaps the most interesting thing about Antarctanax is where and when it lived:
“The more we discover about prehistoric Antarctica, the stranger it is. We thought that Antarctic animals would be similar to the ones that were living in southern Africa since those landmasses were joined back then. But we’re finding that Antarctica’s wildlife is surprisingly unique,” explains Peecook.
Approximately two million years before Antarctanax came into existence, the Earth suffered one of the greatest extinction events in history.
Climate change, caused by volcanic eruptions, killed 90% of all animal life on the surface.
In the immediate aftermath of that extinction event, new groups of animals competed to fill in the gaps.
According to scientists, the archosaurs were one of the groups that experienced enormous growth.
“Before the mass extinction, archosaurs were only found around the Equator, but after it, they were everywhere,” says Peecook.
“And Antarctica had a combination of these brand-new animals and stragglers of animals that were already extinct in most places—what paleontologists call ‘dead clades walking.’ You’ve got tomorrow’s animals and yesterday’s animals, cohabiting in a cool place,” concluded Peecook.
More about the competing bizarre amphibians and crocodilians of the Antarctic from Ben G Thomas: