ABSTRACT The Eocene-Oligocene boundary (EOB) marks a period of remodeling in the metatherian faunas of South America. Paucituberculata was one of the groups that successfully diversified as the climate and environment conditions changed, and they became, during the first part of the Neogene, an important component of micromammal assemblages. Among paucituberculatans, the non-pichipilid palaeothentoids (NPP) has been recognized as the clade that diversified most widely in post-EOB times. Here we explore the evolutionary response of the NPP to the climatic-environmental changes around the EOB, by analysing the temporal patterns of disparity, taxonomic diversity and body mass in a phylogenetic context. To asses the magnitude of the NPP radiation comparisons based on these macroevolutionary parameters were done with its sister-group Pichipilidae, and its next closest relative, the Caenolestidae. In all considered parameters, NPP reached values significantly higher than the remaining paucituberculatans clades. From its initial diversification in the middle Eocene, taxonomic diversity increased through time, but it was decoupled from disparity across the EOB, and from the late Oligocene to early Miocene. The Oligocene emerges as the key period in NPP evolution, which is evidenced by a significant and concordant expansion of disparity and taxonomic diversity, suggesting evolution into empty ecospace.

中文翻译：

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南美 Paucituberculata（Metatheria：Marsupialia）的进化：始新世-渐新世边界的适应性辐射和气候变化

摘要 始新世-渐新世边界（EOB）标志着南美洲后兽类动物群的重塑时期。Paucituberculata 是随着气候和环境条件的变化而成功多样化的群体之一，它们在新近纪的第一部分成为微型哺乳动物组合的重要组成部分。在 paucituberculatans 中，非 pichipilid palaeothentoids (NPP) 已被认为是后 EOB 时代多样化最广泛的进化枝。在这里，我们通过分析系统发育背景下的差异、分类多样性和体重的时间模式，探索 NPP 对 EOB 周围气候环境变化的进化响应。为了评估基于这些宏观进化参数的 NPP 辐射比较的大小，是与其姊妹群 Pichipilidae 进行的，和它的下一个近亲，Caenolestidae。在所有考虑的参数中，NPP 达到的值明显高于其余的 paucituberculatans 进化枝。从它在始新世中期的最初多样化开始，分类多样性随着时间的推移而增加，但它与整个 EOB 以及从渐新世晚期到中新世早期的差异脱钩。渐新世是 NPP 演化的关键时期，差异和分类多样性的显着且一致的扩展证明了这一点，这表明演化为空的生态空间。但它与整个 EOB 以及从渐新世晚期到中新世早期的差异脱钩。渐新世是 NPP 演化的关键时期，差异和分类多样性的显着且一致的扩展证明了这一点，这表明演化为空的生态空间。但它与整个 EOB 以及从渐新世晚期到中新世早期的差异脱钩。渐新世成为 NPP 演化的关键时期，差异和分类多样性的显着且一致的扩展证明了这一点，这表明演化为空的生态空间。