Poposaurus is a genus of reptile from the Late Triassic. It was a crurotarsan archosaur which lived in what is now Wyoming, Utah, Arizona, New Mexico and Texas. The type species, Poposaurus gracilis, was described by M. G. Mehl in 1915. Read more
Fossil from 275 million years ago shows oldest abscess
The first-known occurrence of an oral infection has been found in a 275-million-year-old fossil. The Labidosaurus hamatus fossil, whose detailed analysis using X-rays is described in Naturwissenschaften journal, shows signs of an abscess. The animal was among the first to have just one set of teeth, rather than continuously replacing them. Read more
The fragmentation of tropical rainforests 300 million years ago helped pave the way for the rise of the dinosaurs, a new study suggests. In the Carboniferous period, North America and Europe lay at the equator and were covered by steamy rainforest. Global warming is thought to have brought about the collapse of these tropical habitats, triggering an evolutionary burst among reptiles. Read more
Reptiles stood upright after mass extinction Reptiles changed their walking posture from sprawling to upright immediately after the end-Permian mass extinction, the biggest crisis in the history of life that occurred some 250 million years ago and wiped out 90% of all species. In a detailed study of 460 fossil tracks of reptiles from below and above the extinction boundary, Tai Kubo and Professor Mike Benton from the University of Bristol have found that before the Permian extinction all the reptiles moved with their arms and legs held sideways in a sprawling posture, just like salamanders and lizards do today. After the mass extinction, the medium-sized and large reptiles of the subsequent Triassic period, walked with their legs tucked underneath their bodies, just like modern mammals.