Frog evolution debate resolved
The fossilized creature, known as Gerobatrachus hottoni, proves that some modern amphibians, frogs and salamanders evolved from an ancient amphibian group called temnospondyls, a Canadian-led team reports in the journal Nature.
"This fossil seals the gap," says team leader Jason Anderson, of University of Calgary Faculty of Veterinary Medicine.
Gerobatrachusboasts both frog and salamander features -- it has two fused bones inthe ankle normally only seen in salamanders, as well as a lightly builtand wide skull similar to that of a frog, the researchers report.
The tiny fossil, measuring 11 centimetres long, also points to when salamanders and frogs evolved into two distinct groups.
"Withthis new data, our best estimate indicates that frogs and salamandersseparated from each other sometime between 240 and 275 million yearsago, much more recently than previous molecular data had suggested,"co-author Robert Reisz, professor, University of Toronto Mississaugasays in a statement released with the study.