MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
Astrapotherium from the Middle Miocene Collón Cura Formation and the decline of astrapotheres in southern South America.
KRAMARZ, A., GARRIDO, A.AND BOND, M.
ASOCIACION PALEONTOLOGICA ARGENTINA
Lugar: Buenos Aires; Año: 2019 vol. 56 p. 290 - 290
Abstract. Astrapotherium is the best-known member of the placental order Astrapotheria. This large herbivore inhabited the Patagonianecosystems during early and middle Miocene times. The genus is widely represented in the early Miocene Santa Cruz Formation, with adozen nominal species, of which Astrapotherium magnum and Astrapotherium burmeisteri are the only ones herein considered as valid. The middleMiocene record was limited to few fragmentary remains from the Río Frías Formation and presumably from the Collón Cura Formation,described as Astrapotherium hesperinum, a species name here interpreted as nomen vanum. Here we describe an almost complete skull withassociated mandible derived from the Collón Cura Formation in the vicinities of Comallo, in Río Negro Province (Argentina). It is by far the mostcomplete astrapothere material from middle Miocene rocks of high latitudes, and it is referred to Astrapotherium guillei sp. nov. It differs fromthe remaining species essentially in lacking P3, achieved convergently with the latest diverging uruguaytheriines. The astrapotheriines diversifiedin high latitudes during the early Miocene, but they retained a stereotyped morphotype and became progressively less diverse, unlike theirNorthern counterparts (the Uruguaytheriinae). Astrapotherium guillei is the latest known Patagonian astrapothere and represents the final expressionof the Astrapotheriinae?s decline thus far.