May 30, 2013
Newly Discovered Amphibian Closes Gap In Albanerpetontid Evolutionary History
redOrbit Staff & Wire Reports - Your Universe Online
Researchers from the University of Portsmouth have discovered a miniature species of amphibian that lived alongside dinosaurs — a creature which they claim fills a gap in the evolutionary history of a now-extinct group of creatures known as the albanerpetontids.According to BBC News, the newly-identified Wesserpeton was approximately the size of a small newt and lived roughly 130 million years ago. While there is no complete skeleton of the amphibian also known as “Wessie,” researchers have managed to amass a large number of isolated bones representing nearly all parts of the creature on the Isle of Wight.
Unlike most amphibians, albanerpetontids had scaly skin and eyelids, indicating that the creatures spent the majority of their time on land. Furthermore, the bones discovered to date suggest that they were more than capable of burrowing, and like some modern salamanders it likely engaged in fierce battles over territory and potential mates. Sharp chisel-like teeth indicate that it was a predator, the university said.
Wessie´s discovery helps fill an evolutionary gap, the researchers noted. Albanerpetontids were first found in rocks of the Middle Jurassic age, and their last known occurrence is in the Late Pliocene — a period of over 165 million years. During that time, skull bones known as frontals gradually changed from bell-shaped to triangular, but previously a portion of that transition had been missing from the fossil record.
“Until the discovery of Wesserpeton there appeared to be an abrupt transition from the more primitive elongated and bell-shaped frontals of the early albanerpetontids to the triangle shaped frontals of later forms,” lead researcher Dr. Steve Sweetman, a fellow at the university´s School of Earth & Environmental Sciences, said in a statement. “The frontals of Wesserpeton are elongated but they are also triangular, neatly filling the gap between the two.”
“From the plant debris beds we have bones of some of the largest creatures to have walked the earth during the Early Cretaceous mixed with those of some of the smallest, including those of Wessie. This is really quite remarkable and it is what makes the dinosaur-bearing rocks of the Isle of Wight so special,” he added.
The creature was named Wesserpeton by Dr. Sweetman and his co-author, Dr. Jim Gardner of the Royal Tyrrell Museum of Palaeontology in Canada, because its bones come from rocks known as the Wessex Formation. A paper detailing their findings has been published online in the journal Acta Palaeontologica Polonica.