The discovery of a "frogamander," a 290 million-year-old fossil that links modern frogs and salamanders, may resolve a longstanding debate about amphibian ancestry, say Canadian scientists.

A team led by Assistant Professor Jason Anderson of the University of Calgary reports on an unusual fossil from the Early Permian period in the journal Nature.

Gaps in the fossil record showing the transformation of one form into another have led to great controversy among scientists who study vertebrate evolution over whether frogs and salamanders share a common ancestor.

The new fossil, Gerobatrachus hottoni, or elderly frog, described by Anderson and team may help set the record straight.

He says the fossil is a "missing link" that connects extinct amphibian group known as the temnospondyls and modern frogs, toads and salamanders.

"It's a perfect little frogamander," says Anderson.