Data from: Arrival and diversification of caviomorph rodents and platyrrhine primates in South America.

Platyrrhine primates and caviomorph rodents are clades of mammals that colonized South America during its period of isolation from the other continents, between 100 and 3 million years ago (Mya). Until now, no molecular study investigated the timing of the South American colonization by these two lineages with the same molecular data set. Using sequences from three nuclear genes (ADRA2B, vWF, and IRBP, both separate and combined) from 60 species, and eight fossil calibration constraints, we estimated the times of origin and diversification of platyrrhines and caviomorphs via a Bayesian relaxed molecular clock approach. To account for the possible effect of an accelerated rate of evolution of the IRBP gene along the branch leading to the anthropoids, we performed the datings with and without IRBP (3768 sites and 2469 sites, respectively). The time window for the colonization of South America by primates and by rodents is demarcated by the dates of origin (upper bound) and radiation (lower bound) of platyrrhines and caviomorphs. According to this approach, platyrrhine primates colonized South America between 37.0 +/- 3.0 Mya (or 38.9 +/- 4.0 Mya without IRBP) and 16.8 +/- 2.3 (or 20.1 +/- 3.3) Mya, and caviomorph rodents between 45.4 +/- 4.1 (or 43.7 +/- 4.8) Mya and 36.7 +/- 3.7 (or 35.8 +/- 4.3) Mya. Considering both the fossil record and these molecular datings, the favored scenarios are a trans-Atlantic migration of primates from Africa at the end of the Eocene or beginning of the Oligocene, and a colonization of South America by rodents during the Middle or Late Eocene. Based on our nuclear DNA data, we cannot rule out the possibility of a concomitant arrival of primates and rodents in South America. The caviomorphs radiated soon after their arrival, before the Oligocene glaciations, and these early caviomorph lineages persisted until the present. By contrast, few platyrrhine fossils are known in the Oligocene, and the present-day taxa are the result of a quite recent, Early Miocene diversification.

阔鼻猴类（Platyrrhine primates）与豚鼠型啮齿类（caviomorph rodents）均为哺乳类演化支，它们在南美洲与其他大陆隔绝的1亿至300万年前（Mya，百万年前）期间成功殖民了南美洲。迄今为止，尚无任何分子研究采用同一套分子数据集，探究这两个类群殖民南美洲的时间节点。
本研究依托60个物种的3个核基因序列（ADRA2B、vWF与IRBP，分别单独使用及合并使用），结合8项化石校准约束，通过贝叶斯宽松分子钟方法（Bayesian relaxed molecular clock approach）估算了阔鼻猴类与豚鼠型啮齿类的起源与分化时间。为考量IRBP基因沿类人猿（anthropoids）分支的进化速率加速可能带来的影响，我们分别在包含与排除IRBP基因的情况下开展年代估算（分别对应3768个位点与2469个位点）。
灵长类与啮齿类殖民南美洲的时间窗口，由阔鼻猴类与豚鼠型啮齿类的起源时间（上限）与辐射演化时间（下限）划定。基于该分析框架，阔鼻猴类殖民南美洲的时间范围为37.0±3.0百万年前（或排除IRBP基因时为38.9±4.0百万年前）至16.8±2.3百万年前（或排除IRBP基因时为20.1±3.3百万年前）；豚鼠型啮齿类的殖民时间范围则为45.4±4.1百万年前（或排除IRBP基因时为43.7±4.8百万年前）至36.7±3.7百万年前（或排除IRBP基因时为35.8±4.3百万年前）。
综合化石记录与本次分子年代估算结果，更受支持的演化场景为：灵长类于始新世（Eocene）末期或渐新世（Oligocene）初期从非洲跨大西洋迁徙至南美洲，啮齿类则在始新世中晚期殖民南美洲。基于我们的核DNA数据，无法排除灵长类与啮齿类同时抵达南美洲的可能性。豚鼠型啮齿类在抵达后不久便发生辐射演化，早于渐新世冰期事件，且这些早期的豚鼠型演化支一直存续至今。与之形成对比的是，渐新世时期的阔鼻猴类化石记录极少，现生类群均源自中新世（Miocene）早期较晚近的辐射演化。