Proc. R. Soc. B doi:10.1098/rspb.2009.0883 (2009) The anomodonts were mammal-like reptiles that were widespread from 270 million years ago until at least 200 million years ago. A new specimen of an animal called Biseridens qilianicus has recently been unearthed in Gansu, China. The specimen is in such good shape (pictured, below) that Jun Liu of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences in Beijing and his colleagues were able to confirm an earlier hunch that this animal is a very early anomodont. In fact, it is the most basal anomodont yet found, meaning that it is a member of the oldest branch on the anomodont family tree. This analysis supports the idea that anomodonts originated on the old northern continent of Laurasia rather than on its southern counterpart, Gondwana, as previously thought.
Holotype of Biseridens qilianicus |