Seismosaurus

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iSeismosaurus
Fossil range: Late Jurassic

A 3D rendering of a seismosaur

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Sauropodomorpha
Infraorder:	Sauropoda
Family:	Diplodocidae
Genus:	Seismosaurus

Binomial name

Seismosaurus hallorum
David Gillette, 1991

This article is about the dinosaur. For the fictional Zoid based on this dinosaur, see Seismosaurus (Zoids).

Seismosaurus, meaning "Earth-shaking lizard," was one of the giant herbivorous dinosaurs of the late Jurassic period. It lived from the Kimmeridgian to the Tithonian age, approximately 154 to 144 million years ago. Its size is highly disputed, with estimates ranging from 37-45m(123.3-150feet) long. Based in Gillete's calculations, it may have been 39m long. Although some weight estimates range as high as 113 tonnes (125 US short tons), it may have weighed about 22 to 27 tonnes (25 to 30 US short tons).

Seismosaurus is known from a partial skeleton discovered in New Mexico in 1979 consisting of vertebrae, pelvis, ribs, and gastroliths. The species was formally recognised in 1991.<ref>David Lambert. The Ultimate Dinosaur Book. New York: Doring Kindersley. ISBN 1-56458-304-X.</ref>

Seismosaurus was a diplodocid closely related to, or perhaps even the same as, Diplodocus <ref name="lucas_et_at_2004">Reappraisal of Seismosaurus, A Late Jurassic Sauropod Dinosaur from New Mexico</ref>. Like other diplodocids, it had nostrils near the tip of its snout (though the nasal openings in the skull were on the top of its head)<ref>Witmer, Lawrence M., 2001, "Nostril Position in Dinosaurs and Other Vertebrates and Its Significance for Nasal Function." Science 293: 850-53.</ref> and its front legs were slightly shorter than its hind legs.

[edit] Classification

A Presentation <ref name="lucas_et_at_2004" /> at the annual conference of the Geological Society of America in 2004 has made a case for Seismosaurus to be reassigned as a species of Diplodocus, namely D. hallorum. They argue that many of the distinctive features of Seismosaurus are either pathological or as a result of misplacement of the vertebrae. it may have been 44m in length.