New remains of Dryornis pampeanus, a fossil cathartid from the Pliocene of Buenos Aires, Argentina

BRITO, M.L.; DEGRANGE, F.J.; SCAGLIA, F.; TAGLIORETTI, M.L.; TAMBUSSI, C.P.

Puerto Madryn

Congreso; Reunión de Comunicaciones de la Asociación Paleontológica Argentina 2018; 2018

ASOCIACION PALEONTOLOGICA ARGENTINA

Cathartidae (?new world vultures?), characterized bytheir soaring flight and carrion based trophic habits, are found in warm and temperatezones of the Americas, where they are recorded from the Eocene. New remains of the putative cathartid Dryornispampeanus Moreno and Mercerat provide more information about the species, originallynamed in 1891 based on a distal fragment of right humerus proceeding from the MonteHermoso Formation (early Pliocene). The new materials MMP 5731 were unearthed inLa Estafeta Beach, Mar del Plata, Buenos Aires Province, from the upper levelsof the Chapadmalal Formation, corresponding to the paleosoil 6 of the Playa LosLobos Alloformation, dated in 3.3 Ma, upper Pliocene. Materials consist of afragmentary tibiotarsus and articulated right pectoral girdle and partial forelimb:complete right humerus, proximal ends of the right ulna and radius, rightcoracoid, right incomplete scapula, and fragment of sternum. This new findingextend the biocron of Dryornys pampeanusto the upper Chapadmalalan age, shortening the faunal differences with theMontehermosan age. Dryornis´ bodymass estimation is 26161 gr (based on the length of the humeral articulationfacet of the coracoid: 28.48 mm), being the largest cathartid registered untilnow. Preliminary phylogenetic analyses show that Dryornis may be a basal giant common vulture, sister to the (Cathartes + Coragyps) clade, although its position among Cathartiformes still seemscontroversial. The new specimen provides detailed new morphological data for Dryornispampeanus, which will beimportant for future evaluations of the phylogenetic relationships and evolutionof the Cathartiformes clade.