CONICET | Buscador de Institutos y Recursos Humanos

Macrochorobates is a genus of armadillos within the subfamily Euphractinae (Chlamyphoridae) restricted to the late Neogene of Argentina. The genus includes the species M. scalabrinii (late Miocene-early Pliocene) and M. chapalmalensis (late Miocene-late Pliocene/Pleistocene; llega al Pleistoceno??). Among them, M. scalabrinii shows the widest geographic distribution, with records coming from Buenos Aires, La Pampa, San Juan, Tucuman, La Rioja, Catamarca, and Jujuy provinces in Argentina. However, most materials are composed of isolated osteoderms, and more complete specimens are quite rare. In this contribution, we analyze and describe the most complete remains of the genus (here interpreted as belonging to M. scalabrini), including, among others, a complete dorsal carapace (FMNH P14510) and a partially complete skull (FMNH P14360) from the late Miocene-early Pliocene of Puerta de Corral Quemado and Santa María Valley in Catamarca province, respectively. A detailed characterization provided the first detailed anatomical description of the skull, and allowed to include it for the first time into a morphological phylogenetic analysis. Results of the analysis revealed a very close affinity with the genus Macroeuphractus (late Miocene-late Pliocene), based on: a) anterior teeth oriented obliquely to the long axis of toothrow, b) very flattened braincase with parietals dorso-ventrally compressed, c) well developed sagittal crest, d) large and wide orbits, e) underdeveloped scapular shield of the dorsal carapace, f) mobile osteoderms with very deviated central figures and undivided peripheral figures. While both of them are big sized armadillos, M. scalabrinii is smaller and develops a much gracile carapace, composed of a lower amount of osteoderms which are proportionally larger than those of Macroeuphractus.

enviar mensaje