Taxonomic revisión of the Glyptodontidae (Mammalia, Xenarthra) Propalaehoplophorinae and a phylogenetic analysis of the Glyptodontidae Hoplophorini

GONZÁLEZ RUIZ, L.R.; ZURITA, A. E.; SCARANO, A.; SCILLATO-YANÉ, G. J.; TEJEDOR, M. F.

Las Vegas (Nevada)

Otro; 71 Annual Meeting of the Society of Vertebrate Paleontology; 2011

The family Glyptodontidae (late Eocene-early Holocene) represents one of the most conspicuous taxa in South America, reaching North America during the Great American Biotic Interchange. From a morphological point of view, these herbivores are characterized by having cephalic, dorsal and caudal armors. More than 65 genera have been recognized up to now. However, those works were made in a strict typological/morphological taxonomic context, without a precise morphological characterization. This situation led to a clear overestimation of the real diversity of this clade, thus, a taxonomic update is evidently necessary. Until now, the scarce cladistic analyses carried out have failed in having bad characterized taxa in most of cases. This situation is especially true for two of the most diverse groups, the Propalaehoplophorinae and the ?Hoplophorinae? Hoplophorini. The Propalaehoplophorinae (late Oligocene, Deseadan SALMA- middle Miocene, Colloncuran SALMA) are one of the most basal Glyptodontidae, while the Hoplophorini (late Miocene, Huayquerian SALMA-early Holocene, Lujanian SALMA), probably its sister group, retain many primitive characters. Here we present the first taxonomic update of both groups (and in fact for all South American Glyptodontidae), and a comprehensive cladistic analysis of the Hoplophorini, including the Propalaehoplophorinae as outgroup. The result shows that the Propalaehoplophorinae are represented by three well defined genera: Propalaehoplophorus (three species), Cochlops (one species) and Eucinepeltus (one species), and two additional controversial genera («Asterostemma» and «Metopotoxus»). In turn, the Hoplophorini includes two genera: Eosclerocalyptus (three species) and Neosclerocalyptus (four species). On the other hand, the cladistic analysis suggests that the Glyptodontidae Hoplophorini is a natural group, characterized by six unambiguous synapomorphies. This result does not agree with previous analyses suggesting that the Hoplophorini is a paraphyletic group.