"This specimen is really rare," said Modesto, who was the principal investigator of the project. "It's the only specimen we know of from this particular part of the Carboniferous and it's the only reptile from that slice of time."

The research will be published in the journal Proceedings of the Royal Society B on Wednesday.

Modesto said the fossil was discovered by a boy and his family on their farmland in Prince County, P.E.I., more than 14 years ago. It was taken to the Royal Ontario Museum in 2004 and about four years ago, Modesto and his team started their research.

The fossil, erpetonyx arsenaultorum, was named after the Arsenault family who made the discovery.