出典:Wikipedia
出典:『Wikipedia』 (2011/06/18 17:33 UTC 版)
Arizonasaurus was an archosaurian reptile from the Mesozoic Era, specifically a ctenosauriscid archosaur from the Middle Triassic (240 million years ago). Arizonasaurus is found in the Middle Triassic Moenkopi Formation of northern Arizona. A fairly complete skeleton was found in 2002 by Sterling Nesbitt. The taxon has a large sailback formed by elongate neural spines of the vertebrae. The type species, Arizonasaurus babbitti, was named by Samuel Paul Welles in 1947. It superficially resembles the sail-backed synapsids Dimetrodon and Edaphosaurus, which lived millions of years earlier during the Late Pennsylvanian and Permian.