From: Kweichow (now Guizhou Province), China.
Age: 247.2 million years old.
Keichousaurus is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the triassic in the triassic-jurassic extinction event. They are among the most common sauropterygian fossils recovered and are often found as nerly complete, articulated skeletons, making them popular among collectors. Keichousaurus and the pachypleurosaur famil, broadly, are sometimes classified within Sauropterygia.
Keichousaurus was highly adapted to the aquatic environment. Individuals of this genus ranged from 15-30cm in length, and had both long necks and long tails, with elongated, five-toed feet. The pointed head and sharp teeth in this genus also indicate that they were fish-eaters. Some recovered specimens feature an especially developed ulna suggesting they may have spent some time on land or in marshes. in addition fossil evidence shows that they had a mobile pelvis to give birth to live young rather than laying eggs. The locomotion of the Keichousaurus probably resembled the ''underwater flight'' that plesiosaurs employed. The flattened forelimbs would likely have acted as stabilizers and control surfaces, such as is seen in extant sea turtles. The intermediate nature of the limb morphology implies that there was also, to some extent, the kind of 'crawling through the water' seen in small freshwater turtles.
This specimen is a juvenile example and the photos show the back of the reptile. The creature was killed by a pyroclastic ash flow from a nearby volcano.
This is an exquisitely preserved specimen however it has been painted to enhance the appearance of the specimen.