Fossil Link in Evolution of Slimy Things

The evolution of many groups of animals are wonderfully well represented in the fossil record. Others, like frogs, are less understood simply because few fossils exist of these creatures and their ancestors.

Recently a team of scientists from the University of Calgary described a new fossil amphibian which helps bridge a gap in the evolution of frogs, toads, and salamanders. The fossil seems to belong to a known group of primitive amphibians. However, this new fossil also shares many traits of modern amphibians.

For example, the number of bones in the spine of Gerobatrachus hottoni is exactly in between the number of bones found in the backs of primitive amphibians and frogs and salamanders living today.

“With this new data our best estimate indicates that frogs and salamanders separated from each other sometime between 240 and 275 million years ago, much more recently than previous molecular data had suggested,” says Robert Reisz of the University of Toronto Mississauga.

Source: Nature.com and University of Calgary
Illustration by Michael W. Skrepnick