Thecodontosaurus, meaning “socket-tooth lizard,” is a genus of sauropodomorph dinosaur from the Norian or Rhaetian age of the Late Triassic Period. Known mainly from “fissure fillings” found in South England and Wales, the original remains were destroyed by the Germans during World War II bombings. However, more fossils have been found at a number of different sites.
Some of the new material collected is of a juvenile specimen that may belong to the species, T. caducus, described by Adam Yates in 2003. However, in a 2007 paper published by Yates, Galton and Kermack, the trio claimed that this species actually belonged to a different genus, which they named Pantydraco.
Thecodontosaurus was 3.9 feet long, 12 inches tall and weighed about 24 pounds at adulthood. It had a short neck supporting a large skull with rather large eyes. Its jaws contained many small- to medium-sized, serrated, leaf-shaped teeth. Its hands and feet had five digits each, and the hands were long and quite narrow with an extended claw on each one. The front limbs were much shorter than the legs, and the tail was much longer than the head, neck and body put together.
Although Thecodontosaurus is not the earliest known member of sauropodomorph dinosaurs, it is the most primitive well-known member. It was originally included under Prosauropods but more recently it has been suggested that Thecodontosaurus and its relatives were prior to the prosauropod-sauropod split.