Old and new specimens of a poorly known glyptodont from the Miocene of Patagonia and their biochronological implications

MARTÍNEZ OSCAR ALFREDO; GONZÁLEZ RUIZ LAUREANO; REATO AGUSTINA; CANO DANIEL MARTÍN

ACTA PALAEONTOLOGICA POLONICA

INST PALEOBIOLOGII PAN

Lugar: Varsovia; Año: 2016

0567-7920

The Palaehoplophorini is a tribe of glyptodonts represented by fragmentary specimens for which the oldest recordsoccur in the Pedregoso and Río Mayo formations (middle?late Miocene) in Patagonia (Argentina). The mammal fossilsfrom those formations were the basis for the recognition of the Mayoan fauna, placed between the Friasian sensustricto/Colloncuran?Laventan and the Chasicoan faunas. The only identified glyptodont from Río Mayo Formation isPalaehoplophorus meridionalis represented only by its type material (i.e., caudal tube) and the precise provenance isunknown. We describe a new specimen of Palaehoplophorus meridionalis collected in the Río Mayo Formation representedby associated osteoderms of the dorsal carapace and postcranial elements, plus part of the type and assignedspecimens that remain unpublished from the old collection. This is the first description of osteoderms from the dorsalcarapace of this species and postcranial elements (the first for a Palaehoplophorini), and the first glyptodont with preciseprovenance from Río Mayo Formation. As result of improving the description and emending the diagnosis, weagree with previous authors about the basal position of Palaehoplophorus meridionalis within the tribe. Finally, wereview the Glyptodontidae association of the Mayoan fauna, which are exclusively represented by Palaehoplophorini(Palaehoplophorus meridionalis and Palaehoplophoroides rothi) and Glyptodontidae indet. This association supports agreater affinity of this fauna with the younger Chasicoan than with the older Friasian sensu stricto/Colloncuran?Laventanfaunas