Dinocephalosaurus

Dinocephalosaurus Temporal range: Anisian, 245–244 Ma PreЄ Є O S D C P T J K Pg N ↓
Photograph (a) of specimen LPV 30280, which contains an fetus (c) and a perleidid fish (e)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Protorosauria
Family:	†Tanystropheidae
Genus:	†Dinocephalosaurus Li, 2003
Type species
Dinocephalosaurus orientalis Li, 2003

Dinocephalosaurus (meaning "terrible-headed reptile") is a genus of long necked, aquatic protorosaur that inhabited the Triassic seas of China. The genus contains the type and only known species, D. orientalis, which was named by Li in 2003. Unlike other long-necked protorosaurs (which form a group known as the tanystropheids), Dinocephalosaurus convergently evolved a long neck not through elongation of individual cervical vertebrae, but through the addition of cervical vertebrae that each have a moderate length. Like other tanystropheids, however, Dinocephalosaurus probably used its long neck to hunt for prey, utilizing a combination of suction created by the expansion of the throat and the fang-like teeth of the jaws to ensnare prey. It was probably a marine animal by necessity, as suggested by the poorly-ossified and paddle-like limbs which would have prevented it from going ashore.

Specimens belonging to the genus were first discovered in a locality near Xinmin in Guizhou, China in 2002. At the same locality, which dates to 244 million years ago, other marine reptiles such as Mixosaurus, Keichousaurus, and Wumengosaurus have also been found. While the type specimen consisted only of a skull and the very front of the neck, additional specimens soon revealed the complete form of the body. Further discoveries of Dinocephalosaurus specimens were made in Luoping, Yunnan, China, starting in 2008. At this locality, Dinocephalosaurus would have lived alongside Mixosaurus, Dianopachysaurus, and Sinosaurosphargis. One specimen discovered at the Luoping locality preserves a fetus within its abdomen, indicating that Dinocephalosaurus gave birth to live young like many other marine reptiles. Dinocephalosaurus is one of the few known members of the Archosauromorpha which are known to give live birth, asides from the metriorhynchids, a group of marine crocodylomorphs.