REGARDING THE DIVERSITY OF GLYPTODONTIDAE (MAMMALIA, XENARTHRA) IN THE LATE PLIOCENE

ZURITA, ALFREDO EDUARDO; TAGLIORETTI, MATIAS A.; DE LOS REYES, MARTÍN; CUADRELLI, FRANCISCO; POIRE, DANIEL

Diamante - Entre Ríos

Jornada; XXIX Jornadas Argentinas de Paleontología de Vertebrados; 2015

CONICET-CICYTTP - Asociación Paleontológica Argentina (APA) - Universidad Autónoma de Entre Ríos

A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalal Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic character is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic view point some species have importance. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis Ameghino biozone. The re-evaluation of the type and referred materials together with new significant findings from the Chapadmalal and El Polvorín Formations indicate that the real diversity of Pliocene Glyptodontidae is more limited than previously supposed, as observed in some Pleistocene lineages. The particular morphology of the exposed surface of the osteoderms characterizing some of the species actually corresponds to a taphonomic alteration, which results in a non-taxonomic character. Thus, the Glyptodontinae P. cha- padmalensis must be replaced as a fossil guide because this species do not present a well characterization, as well as the species traditionally included in the genera Urotherium Castellanos, Trachycalyptus Ameghino and Lomaphorus Ameghino. Taking into a count the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that clearly contrasts with its records in the Pleistocene), whereas Eosclerocalyptus Ameghino, ?Plohophorini? (Plohophorus figuratus Ameghino) and Doedicurinae (cf. Eleutherocercus antiquus Ameghino) are among the most recorded taxa.