ABSTRACT

The oldest record of a carnivoran mammal in South America corresponds to the extinct procyonid Cyonasua (late Miocene–early Pleistocene). Up to now, this genus was recorded in Argentina, Uruguay, Bolivia, and Venezuela. In this contribution, we report the first occurrence of Cyonasua in the Pacific coast of Peru, recovered from the late Miocene marine deposits of the Pisco Formation. The fossil material comprises postcranial bones of two individuals (MNHN SAS 1625: left femur; MNHN PPI 262: axis, right talus, and left metatarsal III). The morphology and sizes of these new fossil specimens, allow us to refer them to Cyonasua sp. This record reaffirms that procyonids were the first North American carnivorans that arrived in South America prior to the full emergence of the Isthmus of Panama, as part of the proto-Great American Biotic Interchange. The presence of Cyonasua in marine deposits of the Pacific margin of Peru is further evidence for its affinity to coastal areas and water bodies, and provide clues to propose the arid coast of western South America as a route for dispersal to the southern lands.

摘要

南美洲食肉动物哺乳动物的最古老记录对应于灭绝的肉食动物类Cyonasua（晚中新世至早更新世）。迄今为止，该属记录在阿根廷，乌拉圭，玻利维亚和委内瑞拉。在这项贡献中，我们报告了秘鲁太平洋海岸首次出现的Cyonasua，从皮斯科组中新世晚期海相沉积中回收。化石材料包括两个个体的颅后骨（MNHN SAS 1625：左股骨； MNHN PPI 262：轴，右距骨和左meta骨III）。这些新化石标本的形态和大小，使我们可以将其称为Cyonasuasp。该记录再次证明了procyonids是在巴拿马地峡完全出现之前作为南美洲原住民生物交流的一部分而首先到达南美的北美食肉动物。Cyonasua在秘鲁太平洋边缘的海洋沉积物中的存在进一步证明了其与沿海地区和水体的亲和力，并为提出南美西部干旱海岸作为扩散到南部土地的途径提供了线索。