Tanystrophaeus

a genus of fossil sauropsidan reptiles of the subclass Lepidosauria. Representatives of the genus lived during the Middle Triassic. They measured as much as 5 m in length. In addition to such archaic characteristics as a parietal cavity, teeth on the palate as well as in the jaws, biconcave vertebrae penetrated by a notochord, and abdominal ribs, they also exhibited distinctive specialized features, for example, an extremely long and mobile neck. Several species have been found in deposits in Western Europe. The taxonomic classification of Tanystrophaeus has not been conclusively established.