Frog-Amander Transitional Fossil Found

Found via Livescience.

A frog-like creature with a stubby tail once paddled through a quiet pond in what is now Texas, snapping up mayflies while keeping an ear out for bellowing mates, new fossil evidence suggests.
That was about 290 million years ago.

In 1995, the amphibian specimen was discovered in fish quarry sediments in Baylor County, Texas, though it wasn't until recently that paleontologists inspected and described the new species. Called Gerobatrachus hottoni after its discoverer Nicholas Hotton, a paleontologist at the Smithsonian Institution, the creature represents a transitional amphibian, sporting features of both frogs and salamanders.

"This amphibian is from near to the point where frogs and salamanders first split," said lead researcher Jason Anderson, a vertebrate paleontologist at the University of Calgary in Canada. "This is kind of an early frog-amander."

The finding, detailed in this week's issue of the journal Nature, supports the idea that frogs and salamanders evolved from one ancient amphibian group called temnospondyls.

Like modern salamanders, the fossil of Gerobatrachus has two fused bones in its ankle. And like modern frogs, the frog-amander sports a large ear drum, or tympanic ear, which Anderson said the ancient amphibian likely used for hearing calls from mates.