Dinocephalosaurus is a genus of long necked, aquatic protorosaur that inhabited the Triassic seas. The age of the fossil horizon that the fossils of Dinocephalosaurus were found in was initially estimated at 228 million years; subsequent study by Wang et al. (2014) indicated that its age was actually 244 ± 1.3 million years. Its name means "terrible headed lizard", because the first specimen found was just a skull, discovered near Xinmin in Guizhou Province, China in 2002. The second specimen found was near the same location and contained the head and much of the postcrainal skeleton, minus the tail. Dinocephalosaurus is the "First record of protorosaurid reptile (Order Protorosauria) from the Middle Triassic of China".