Camarasauridae

Camarasauridae is a family of small to medium-sized sauropod dinosaurs occupying a basal position within Macronaria, one of the two major branches of Neosauropoda. Camarasaurids are recognizable by their comparatively short necks and short skulls bearing large nostril openings and broad, spoon-shaped teeth packed along a thick jaw; the biomechanics of their neck vertebrae suggest they raised and lowered the neck vertically rather than sweeping it from side to side like most diplodocids. Camarasaurus is the only genus universally accepted as a member, though the Portuguese Lourinhasaurus is treated as a camarasaurid in most analyses, and forms such as Tehuelchesaurus, Bellusaurus, and Oplosaurus have been proposed with less certainty. The group is best known from the Late Jurassic Morrison Formation of North America and was largely restricted to the northern continents during the Late Jurassic.