New Specimen Of Apatosaurus Ajax Sauropoda Diplodocidae From The Morrison Formation Upper Jurassic Of Wyoming Usa Paul Upchurch by Paul Upchurch, Yukimitsu Tomida, And Paul M. Barrett 9784878030109, 4878030100 instant download after payment.

ABSTRACTIn 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 unrecognised phylogenetic structure and indicates the presence of four valid species: A. ajax (the type species), A. excelsus, A. louisae, and 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 geno-type 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.