Megatherioidea (Mammalia, Xenarthra, Tardigrada) from the Pinturas Formation (Early Miocene), Santa Cruz Province (Argentina) and their chronological implications

BRANDONI, D.; GONZALEZ RUIZ, L.R.; TEJEDOR, M. F.; MARTIN, G. M.; FLEAGLE, J.

PALAEONTOLOGISCHE ZEITSCHRIFT

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2016 vol. 90 p. 619 - 628

0031-0220

Pyroclastic and epiclastic continental sedimentsbearing the ??fauna Astrapothericulense?? from the PinturasFormation of Ameghino crop out mainly at several localitiesat the upper valley of the Pinturas River and itstributaries, northwestern Santa Cruz Province, Argentina.These continental sediments are referred to the BurdigalianStage and constitute the basis for the recognition of thePinturas Formation. The fauna recorded in the PinturasFormation mainly consists of mammals, specially rodents,native ungulates, xenarthrans and primates. Here wedescribe the first association of Megatherioidea (Mammalia,Xenarthra, Tardigrada) from different localities ofthe Pinturas Formation with accurate geographic andstratigraphic provenance. The Megatherioidea from thePinturas Formation presented herein are represented by (1)Schismotherium cf. binum; (2) Hapalops sp.; and (3) aMegatherioidea indet. In addition, the holotypes of Schismotheriumbinum (MACN A 11750), Hapalops curvus(MACN A 11140), and Pelecyodon arcuatus werecollected from the ??fauna Astrapothericulense?? ofAmeghino; unfortunately, it is not easy to determine if theywere collected from the Pinturas Formation since they arepart of Ameghino?s Collection (MACN), but were collecteda time when the Pinturas Formation had not yet beenproposed. The presence of a species of Schismotherium andof Hapalops in the Pinturas Formation represent accurateearly records for these genera, but not necessarily theearliest. The age of the Pinturas Formation could overlap,partially or totally, with the age of the Santa Cruz Formationat the Atlantic coast, where most Early MioceneMegatherioidea were collected.