IMPORTANCIA BIOESTRATIGRÁFICA DE UN SINGULAR ARMADILLO (XENARTHRA, DASYPODIDAE) DEL PALEÓGENO DEL NOROESTE ARGENTINO

HERRERA CLAUDIA; GRACIELA ESTEBAN; CECILIA EUGENIA DEL PAPA

Congreso; XX Congreso Geologico Argentino; 2017

Bioestratigraphic importance of a singular armadillo (Xenarthra, Dasypodidae) of the Paleogene of Argenti-nean Northwest. A new specimenof Pucatherium parvum is reportedfrom the lower levels of the Upper LumbreraFormation that outcrops in Salta Province.An almost complete dorsal caparace and several remains of postcranium were preserved providing important information about this particular taxon. The specimen is comparable to Dasy- pus novemncinctus, howeverthe osteoderms are very small. There is noevidence of pseudoshield or scapular shield nor pelvic shield. The dorsal caparace would be fully integrated by movable osteoderms, granting a high degree of mobilityin the anteroposterior axis. A dating U I Pb of 39.9 + 0.4 Ma from the Upper LumbreraFormation limits the biocron of Pucatherium parvum to the middle Eocene.This, added to the broad geographic distribution of the taxon, makes it possibleto correlate the Upper LumbreraFormation with Quebrada de los Colorados, Geste and CasaGrande formations.