About 240 million years ago, a 15-foot amphibian with a nasty bite ruled the Antarctic plains, say paleontologists who have described the creature for the first time. Fossils show that the predator, newly named Kryostega collinsoni, had an extra set of teeth protruding from the roof of its mouth, which helped it shred flesh and hold struggling prey still in its mouth.
The animal, which researchers called Antarctica’s top predator in the Triassic Period, resembled a modern crocodile but was actually a temnospondyl, a prehistoric amphibian that was an early relative of salamanders and frogs. Because of their odd mixture of characteristics, members of this group are sometimes nicknamed “crocamanders” or “frogodiles” [Discovery News]. The new species will be described in the forthcoming issue of the Journal of Vertebrate Paleontology.
All of the large crocamanders had a moment of glory during the Triassic Period, before dying out in the extinction event that marks the boundary of the Jurassic Period. During Kryostega‘s time, the continents were still congealed in one supercontinent called Pangaea…. Antarctica itself was located farther north and attached to South Africa, South America, and Australia. The continent was also much warmer back then, crisscrossed by large rivers and primeval forests [National Geographic News].
While researchers believe that all the crocamanders had teeth attached to their palates, the Kryostega‘s extra set impressed researchers by being bigger and longer than usual. “Its teeth, compared to other amphibians, were just enormous. It leads us to believe this animal was a predator taking down large prey,” said [lead researcher] Christian Sidor…. “We think Kryostega was an aquatic animal, so it probably ate mostly fish and other amphibians living in the river alongside it,” he said. “However, like modern crocodiles, if land-living animals strayed too close to the river’s edge, I expect that it would have been able to drag them in” [LiveScience].
Image: Christian Sidor