Class Sauropsida, Order Nothosauroidea, Family Pachypleurisauridae

Geologic Time: Early Triassic, Spathian Stage (about 242 m.y.a.)

Size: 88 mm long

Fossil Site: Huxia Formation, Guanglin, Guizhou Province of China

This is the fossil of a juvenile semi-aquatic reptile from the Triassic of China known as Keichousaurus hui. The Keichousaurs were thought to be able to make their way on land owing to strong limbs (note the robust ulna).The Keichosaurs were members of the Pachypleurisauridae, and as such were related to their contemporaries the Nothosaurs (indeed, at one point they were referred to the Nothosauridae). The genus derives its name from the 1957 location in Keichow Province where they were first discovered. With a mximum size of some 300 mm, this one is a juvenile example which is well articulated. Some believe they lived in a marshy environment. The Pachypleurosaurs are believed to have evolved in China, making their way to Europe via the northern border of the Tethys Sea. None of the later European members of the family had the massive limb bones seen in Keichousaurus.