Department of Anthropology, De Anza College, Cupertino, California 95104, USA.
Turkana Basin Institute, Social and Behavioral Sciences Building N-507, Stony Brook University, Stony Brook, New York 11794-4364, USA.
Nature. 2017 Aug 9;548(7666):169-174. doi: 10.1038/nature23456.
The evolutionary history of extant hominoids (humans and apes) remains poorly understood. The African fossil record during the crucial time period, the Miocene epoch, largely comprises isolated jaws and teeth, and little is known about ape cranial evolution. Here we report on the, to our knowledge, most complete fossil ape cranium yet described, recovered from the 13 million-year-old Middle Miocene site of Napudet, Kenya. The infant specimen, KNM-NP 59050, is assigned to a new species of Nyanzapithecus on the basis of its unerupted permanent teeth, visualized by synchrotron imaging. Its ear canal has a fully ossified tubular ectotympanic, a derived feature linking the species with crown catarrhines. Although it resembles some hylobatids in aspects of its morphology and dental development, it possesses no definitive hylobatid synapomorphies. The combined evidence suggests that nyanzapithecines were stem hominoids close to the origin of extant apes, and that hylobatid-like facial features evolved multiple times during catarrhine evolution.
现生大猿类（人类和猿类）的进化历史仍未得到充分了解。在关键的中新世时期，非洲的化石记录主要由孤立的下颚和牙齿组成，关于猿类颅骨进化的知识很少。在这里，我们报告了迄今为止描述的最完整的化石猿类颅骨，它来自肯尼亚 1300 万年前的中新世中期遗址纳普杜特（Napudet）。这个婴儿标本，即 KNM-NP 59050，根据其通过同步加速器成像可见的未萌出的恒牙，被归为一种新的 Nyanzapithecus 物种。其耳道有完全骨化的管状外鼓室，这一衍生特征将该物种与冠类人猿联系在一起。尽管它在形态和牙齿发育的某些方面与一些长臂猿相似，但它没有明确的长臂猿共有衍征。综合证据表明，Nyanzapithecines 是接近现生猿类起源的原始人科动物，而类人猿的面部特征类似于长臂猿的特征在进化过程中多次进化而来。
