Nuevos materiales de Macranhinga paranensis Noriega (Aves: Pelecaniformes: Anhingidae) del Mioceno de la provincia de Entre Ríos, Argentina

DIEDERLE, J. M.; NORIEGA, J. I.; ACOSTA HOSPITALECHE, C.

REVISTA BRASILEIRA DE PALEONTOLOGIA

SOC BRASILEIRA PALEONTOLOGIA

Lugar: Porto Alegre; Año: 2012 vol. 15 p. 203 - 210

1519-7530

Macranhinga paranensis Noriega, taxon described on the basis of tarsometatarsi, is known by dissociated remains of both girdles and limb bones coming from the ?Conglomerado osífero? or ?Mesopotamian? at Entre Ríos Province, Argentina (= base of the Ituzaingó Formation; late Miocene). In this contribution we report the first record of four isolated cervical vertebrae which are assigned to M. paranensis, coming from the Paraná Formation (middle-late Miocene) at La Ensenada stream (Diamante city, Entre Ríos Province) and from the ?Conglomerado osífero? at La Toma Vieja fossiliferous locality (Paraná city, Entre Ríos Province). The systematic assignment of the new material is supported by different ratios calculated among the dimensions of vertebrae, pelvic girdles, and tarsometatarsi referred to M. paranensis, which were compared with the same proportions obtained in closed related taxa. The seventh vertebra presents several differences with that of Anhinga anhinga (Linnaeus) in the morphology of the foramen vertebrale and the facies articularis cranialis; the fifthteenth vertebra is very similar to that of M. ranzii Alvarenga & Guilherme and has the zygapophysis cranialis proportionally broader and projected more posteriorly than in A. anhinga. Finally, the eighteenth vertebra has the foramen transversarium more rounded, the base of the zygapophysis caudalis with less ridged borders, and the torus dorsalis more prominent caudally than in A. anhinga. Thus, morphology, size, and metric proportions support the reference of the new materials to M. paranensis. The record of M. paranensis in the Paraná Formation (middle-late Miocene) extends the temporal range of this taxon.