Diatryma, Cope, 1876

Genus DIATRYMA Cope, 1876

Type species. Diatryma gigantea Cope, 1876 , by monotypy.

Emended differential diagnosis. Differs from Gastornis Hébert, 1855 (as exemplified by the specimens from the Reims area, which were originally assigned to G. edwardsii ) in that the scapulocoracoid is straight, with essentially no mediolateral or dorsoventral curvature; the body of the coracoid is dorsoventrally flattened (curved in Gastornis ) and pierced by a large foramen (which may or may not be homologous to the foramen nervi supracoracoidei; see description); the tarsometatarsus is stouter, with an elongation index (ratio length of bone to mediolateral width of proximal end) of less than 2.8 ( 2.9‒3.8 in the species of Gastornis ), the proximal and distal ends are much wider mediolaterally than the shaft, the midsection of the shaft shows a mediolateral constriction, and the trochlea metatarsi IV is more laterally splayed and the incisura intertrochlearis lateralis is wider.

Remarks. The above diagnosis is based on material referred to Diatryma gigantea , even though all of the above-listed diagnostic features also pertain to D. geiselensis . For Gastornis parisiensis , the type species of the taxon Gastornis , comparisons are made with material originally assigned to G. edwardsii .