First North American fossil monkey and early Miocene tropical biotic interchange
First North American fossil monkey and early Miocene tropical biotic interchange
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DOI：
10.1038/nature17415
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发表时间：
2016-05-12
期刊：
影响因子：
64.8
通讯作者：
MacFadden, Bruce J.
中科院分区：
文献类型：
--
作者：
Bloch, Jonathan I.;Woodruff, Emily D.;MacFadden, Bruce J.
新大陆猴（阔鼻猴）是北美和南美现代热带生态系统的一个不同组成部分，但它们在热带地区的早期进化历史在很大程度上是未知的。分子分歧估计表明，灵长类动物抵达热带中美洲，即北美大陆的最南端，并从 3-4 百万年前巴拿马地峡的出现开始，从南美洲进行了几次扩散 (Ma)(1)。然而，中美洲完全没有灵长类动物化石，限制了我们对它们在新大陆历史的了解。在这里，我们首次描述了从北美大陆发现的猴子化石，这是已知最古老的冠扁鼻，来自巴拿马运河盆地拉斯卡斯卡达斯地层中精确年代为 20.9Ma 的地层。这一发现表明，现存新大陆猴的科级多样化发生在热带地区，对头猴科的新分化估计在 22 至 25 Ma 之间，并为南美洲和北美洲之间的哺乳动物交流提供了最古老的化石证据。这一时间与最近中新世早期相对狭窄的中美洲海道的构造重建(2,3)一致，与许多其他动物和植物类群的水上扩散推断一致(4)。在巴拿马发现的一种早期中新世灵长类动物，为当时新世界猴在环加勒比热带地区的分布提供了证据，海洋屏障并不能完全限制它们向北移动，需要一系列复杂的生态因素来解释它们在北美高纬度地区经过充分采样的类似年龄地区的消失。
New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma)(1). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions(2,3) of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants(4). Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.