Abstract We present two new Paleogene fossiliferous sites that provide the first mammal remains for the Malargue Group in the Neuquen basin of southeastern Mendoza Province, Argentina. Identified taxa from Agua de Flores-Agua de Isaac: Kibenikhoria sp., Oldfieldthomasiidae indet., ?Henricosborniidae indet., and a large Notoungulata probably related to the Isotemnidae. Taxa from Liu Malal: cf. Kibenikhoria and Notopithecidae gen. et sp. nov. Based on facies composition and geological distribution, we consider that the Cenozoic deposits from these fossiliferous localities correspond to the already defined Puesto Fortunata Formation. This unit is correlated to the Coihueco Formation, the top of the Malargue Group in the northern Neuquen basin, and its mammal content supports the proposed hiatus between the ~40 Ma and 20 Ma based on chronostratigraphy. The presence of Kibenikhoria in the local faunas of southeastern Mendoza extends the geographic range of this genus so far known in Patagonia to central-west areas of Argentina and supports an early-middle Eocene age for the fossil-bearing levels of the Puesto Fortunata Formation.

中文翻译：

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Malargüe Group 的第一批哺乳动物组合：对内乌肯盆地北部（阿根廷）古近纪演化的影响

摘要 我们展示了两个新的古近纪化石遗址，它们为阿根廷门多萨省东南部内乌肯盆地的马拉格群提供了第一批哺乳动物遗骸。来自 Agua de Flores-Agua de Isaac 的已识别分类群：Kibenikhoria sp.、Oldfieldthomasiidae indet.、?Henricosborniidae indet.，以及可能与 Isotemnidae 相关的大型 Notoungulata。来自 Liu Malal 的分类群：cf. Kibenikhoria 和 Notopithecidae gen。等 sp. 十一月 根据相组成和地质分布，我们认为来自这些含化石地区的新生代矿床对应于已经定义的 Puesto Fortunata 组。该单元与内乌肯盆地北部 Malargue Group 顶部的 Coihueco 组相关，其哺乳动物含量支持基于年代地层学的约 40 Ma 和 20 Ma 之间的间隔。