我们关于灵长类演化最早阶段的知识受限于化石记录中所存在的空白。来自中国“始新世”早期（距今5500万年前）的一种很小的、非常古老的灵长类动物的一个近乎完整的、基本上还通过关节连接在一起的骨架的发现，为这个问题提供了一些线索。这一新发现的灵长类动物似乎是眼镜猴的最早已知近亲，说明类人猿与其他灵长类动物分化的时间非常早。这种动物跟现代“矮鼠狐猴”大小差不多，其骨架特征说明它是一种灵敏的食虫动物，习惯白天活动。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi:10.1038/nature12200
The oldest known primate skeleton and early haplorhine evolution
Xijun Ni, Daniel L. Gebo, Marian Dagosto, Jin Meng,Paul Tafforeau, John J. Flynn & K. Christopher Beard
Reconstructing the earliest phases of primate evolution has been impeded by gaps in the fossil record, so that disagreements persist regarding the palaeobiology and phylogenetic relationships of the earliest primates. Here we report the discovery of a nearly complete and partly articulated skeleton of a primitive haplorhine primate from the early Eocene of China, about 55?million years ago, the oldest fossil primate of this quality ever recovered. Coupled with detailed morphological examination using propagation phase contrast X-ray synchrotron microtomography, our phylogenetic analysis based on total available evidence indicates that this fossil is the most basal known member of the tarsiiform clade. In addition to providing further support for an early dichotomy between the strepsirrhine and haplorhine clades, this new primate further constrains the age of divergence between tarsiiforms and anthropoids. It also strengthens the hypothesis that the earliest primates were probably diurnal, arboreal and primarily insectivorous mammals the size of modern pygmy mouse lemurs.
