Describer

Marsh, 1877

Time

Jurassic Late Kimmeridgian Tithonian

Classification

Saurischia Sauropodomorpha Sauropoda Diplodocidae Diplodocinae

Diet

Herbivore

Fossilsite

Morrison Formation, Colorado, Wyoming, US

Fall Under

Apatosaurus

Info

Typespecies - Skull

Apatosaurus = Brontosaurus (Marsh, 1879) Elosaurus (Peterson & Gilmore, 1902)

Apatosaurus > Apatosaurus ajax = Atlantosaurus ajax (Marsh, 1877) - Steel, 1970 = Brontosaurus ajax (Marsh, 1877) - Bakker, 1986 = Atlantosaurus laticollis (Marsh, 1879) - Steel, 1970 = Atlantosaurus excelsus (Marsh, 1879) - Steel, 1970 = Camarasaurus excelsus (Marsh, 1879) - Osborn vide von Huene, 1929 = Apatosaurus amplus (Marsh, 1881) - Gilmore, 1936 = Atlantosaurus amplus (Marsh, 1881) - Steel, 1970

Apatosaurus > Apatosaurus ajax (Marsh, 1877) >> Apatosaurus laticollis (Marsh, 1879) Atlantosaurus immanis (Marsh, 1878)

Apatosaurus > Apatosaurus excelsus (Marsh, 1879) >> Brontosaurus excelsus (Marsh, 1879) >>> Brontosaurus amplus (Marsh, 1881) Elosaurus parvus (Peterson & Gilmore, 1902)

Apatosaurus > Apatosaurus louisae (Holland, 1915) = Atlantosaurus louisae (Holland, 1915) - Steel, 1970 = Brontosaurus louisae (Holland, 1915) - Bakker, 1986

2 partial skeletons, braincase

Upchurch, P., Tomida, Y. and Barrett , P.M. (2004) A new specimen of Apatosaurus ajax (Sauropoda, Diplodocidae) from the Morrison Formation (Upper Jurassic) of Wyoming, USA. National Science Museum Monographs No.26 ISSN 1342-9574 National Science Museum, Tokyo December, 2004.

Abstract: In 1993, a nearly complete postcranial skeleton of Apatosaurus was recovered from the Morrison Formation (Upper Jurassic: Kimmeridgian Tithonian) near Thermopolis, Wyoming (USA). This specimen was purchased by the National Science Museum, Tokyo, where it has been mounted for public display. Description of this new Apatosaurus material has yielded additional anatomical data that have been used to revise the generic diagnosis and species-level taxonomy of the genus. A specimen-level cladistic analysis of individuals referred to Apatosaurus identifies hitherto unrecognized phylogenetic structure and indicates the presence of four valid species: Apatosaurus ajax (the type species), Apatosaurus excelsus, Apatosaurus louisae, A.parvus (comb. nov.). The latter species is based on material of Elosaurus parvus from the Morrison Formation of Sheep Creek, Wyoming (USA). The cladistic analysis indicates that the Tokyo Apatosaurus can be referred to A. ajax, which makes the current study the most detailed description of this genotype species. Revised generic and specific diagnoses have allowed re-evaluation of various Specimens that have previously been assigned to Apatosaurus, including juvenile material from Oklahoma.