Sauropod

Sauropoda Temporal range: Upper Triassic – Upper Cretaceous
Mounted skeleton of Apatosaurus Carnegie Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsid
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Sauropodomorpha
Infraorder:	Sauropoda Marsh, 1878

Sauropoda are an infraorder of saurischian ("lizard-hipped") dinosaurs. They had very long necks, long tails, small heads (in comparison to the rest of their body), and thick, pillar-like legs and peg-like teeth.

They are notable for the enormous size of some species. The group includes the largest animals ever to have lived on land. Well-known genera include Brachiosaurus, Diplodocus, Apatosaurus and Brontosaurus.

Sauropods first appeared in the Upper Triassic period. Their probable ancestral group was the Prosauropoda.

By the Upper Jurassic (150 million years ago), sauropods had become widespread (especially the diplodocids and brachiosaurids).

By the Upper Cretaceous, the diplodocids and brachiosaurs been replaced by the titanosaurs, which had a near-global distribution. They were larger relatives of the brachiosaurs. As with all other non-avian dinosaurs, the titanosaurs died out in the Cretaceous–Paleogene extinction event. Fossilised remains of sauropods have been found on every continent, including Antarctica.

The name Sauropoda was coined by O.C. Marsh in 1878.^[1] Sauropods are one of the most recognizable groups of dinosaurs, and have become a fixture in popular culture due to their large sizes. Complete sauropod fossil finds are rare. Many species, especially the largest, are known only from isolated and disarticulated bones. Many near-complete specimens lack heads, tail tips and limbs.

1. ↑ Marsh, O.C. (1878). "Principal characters of American Jurassic dinosaurs, Part I". American Journal of Science and Arts. 16: 411–416.