The earliest record of North American mammals in South America is significant for constraining the timing of intercontinental faunal interchange. At present, the oldest securely dated remains of a North American terrestrial mammal in South America pertain to a late Miocene procyonid; a few other North American mammal groups are present in late Miocene and early Pliocene outcrops in South America, but most are not recorded until the late Pliocene or Pleistocene, after the complete emergence of the Panamanian Isthmus. This long-established pattern has recently been called into question by reports of a proboscidean, two tayassuids, and a dromomerycine cervoid in supposed late Miocene deposits of Peruvian Amazon. In this contribution, we analyze the taxonomic identities and stratigraphic provenances of the tayassuid and dromomerycine fossils in detail. We conclude that these specimens are not distinguishable from modern tayassuids (Tayassu pecari and Dicotyles tajacu) and cervids, and that previous taxonomic identifications are based on misinterpretation of characters or inadequate specimens. In addition, there is insufficient evidence to support a late Miocene age for these terrestrial cetartiodactyl fossils; the stratigraphic provenance of the specimens is highly dubious, and the fossils are likely Quaternary in age.

中文翻译：

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关于南美中新世Tayassuiduidae和Dromomerycinae（哺乳动物，Cetartiodactyla）的假定存在

在南美，北美哺乳动物的最早记录对于限制洲际动物区系交换的时间具有重要意义。目前，南美洲北美陆生哺乳动物中最古老的具日期安全的遗骸与中新世的procyonid有关。在南美的中新世晚期和上新世早期露头中，还存在其他一些北美哺乳动物群，但是直到巴拿马地峡完全出现后，才记录下大多数直到上新世或更新世晚期。最近在秘鲁亚马逊地区所谓的中新世晚期沉积的一个长喙,、两个梭子鱼和一个德罗美霉素的后遗症引起了人们的质疑，这种长期存在的模式受到了质疑。在此贡献中，我们详细分析了地衣类和地罗莫瑞星化石的分类学特征和地层物证。我们得出的结论是，这些标本无法与现代tayassuid（Tayassu pecari和Dicotyles tajacu）和宫颈区分开，并且以前的分类学鉴定是基于对字符的错误解释或标本不足。此外，没有足够的证据支持这些陆上鲸蜡十二指肠化石的中新世晚期。标本的地层来源高度可疑，化石年龄很可能是第四纪。