A Triassic aquatic protorosaur with an extremely long neck.

By Middle Triassic time, a number of reptile lineages had diversified in shallow epicontinental seas and intraplatform basins along the margins of parts of Pangea, including the giraffe-necked protorosaurid reptile Tanystropheus from the Western Tethys (Europe and the Middle East), which grew to approximately 5 to 6 m long. Here we report another long-necked fossil, Dinocephalosaurus, from southwestern China, recently collected in Middle Triassic marine deposits approximately 230 million years old. This taxon represents unambiguous evidence for a fully aquatic protorosaur. Its extremely elongated neck is explained as an adaptation for aquatic life, perhaps for an increase in feeding efficiency.