For more than three years, scientists from the University of Chicago and Peking University in Beijing have been collecting thousands of salamander fossils, many of which preserve the entire skeleton and impressions of soft tissues, from seven excavation sites in Mongolia and China. Prior to the discovery in 1996 of the Chinese sites, scientists had complete salamander fossils dating back only to the Tertiary period, which began 65 million years ago.
Its remarkable to have the earliest-known salamanders with so much diversity, so many specimens and such high-quality preservation, said Neil Shubin, Ph.D., professor and chairman of organismal biology and anatomy at the University of Chicago and lead author in the study. Usually when you find the earliest-known animal, you only have one representative. But we have thousands. Its a real opportunity to look at how salamanders have evolved.
To date, the scientists have discovered five new species of salamanders from the Asian sites one of which, Chunerpeton tianyiensis, is described in the March 27, 2003, issue of the journal Nature.
According to the paper, the newly found species closely resembles the North American hellbender, a common salamander currently found in Asia, as well as in the Allegheny Mountains near Pittsburgh, Penn.
Most of the variations in the fossil animal are due to small changes in the shape of the bones in the front of the skull, in the features of the fingers and toes, and in variations of the ribs. One unique feature is that it bears unicapitate ribs, meaning the rib has only one facet, or head, where it connects to the vertebra. Most modern salamanders have two-headed ribs.
A volcanic eruption in northern China during the Middle Jurassic period (165 to 180 million years ago) provid
Contact: Catherine Gianaro
University of Chicago Medical Center