When the world's land was congealed in one supercontinent 240 million years ago, Antarctica wasn't the forbiddingly icy place it is now. But paleontologists have found a previously unknown amphibious predator species that probably still made it less than hospitable.
The species, named Kryostega collinsoni, is a temnospondyl, a prehistoric amphibian distantly related to modern salamanders and frogs. K. collinsoni resembled a modern crocodile, and probably was about 15 feet in length with a long and wide skull even flatter than a crocodile's.
In addition to large upper and lower teeth at the edge of the mouth, temnospondyls often had tiny teeth on the roof of the palate. However, fossil evidence shows the teeth on the roof of the mouth of the newly found species were probably as large as those at the edge of the mouth.
"Its teeth, compared to other amphibians, were just enormous. It leads us to believe this animal was a predator taking down large prey," said Christian Sidor, a University of Washington associate professor of biology and curator of vertebrate paleontology at the Burke Museum of Natural History and Culture at the UW.
Sidor is lead author of a paper describing the new species published in the September issue of the Journal of Vertebrate Paleontology. Co-authors are Ross Damiani of Staatliches Museum für Naturkunde Stuttgart in Germany and William Hammer of Augustana College in Rock Island, Ill. The work was funded in part by the National Science Foundation and the Alexander von Humboldt Foundation.
The scientists worked from a fossilized piece of the snout of K. collinsoni, analyzing structures present in more complete skulls for other temnospondyl species that had similar size characteristics.
"The anatomy of the snout tells us what major group of amphibian this fossil belonged to," Sidor said.
eeth at the edge of the mouth, as well as on the palate roof, were clearly visible, and the presence of structures similar to those that allow fish and amphibians to sense changes in water pressure led the researchers to conclude that the species was aquatic.
The fossilized piece of snout also contains a nostril, which aided the scientists in judging proportions of the head when comparing it to other fossils. They estimated the skull was about 2.75 feet long and perhaps 2 feet across at its widest point.
"Kryostega was the largest animal in Antarctica during the Triassic," Sidor said.
Yikes! 4.5m long salamanders...well...not really salamander, but...
National Geographic has more too.
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