Patel Biren A, Yapuncich Gabriel S, Tran Cassandra, Nengo Isaiah O
Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.
J Hum Evol. 2017 Jul;108:176-198. doi: 10.1016/j.jhevol.2017.03.013. Epub 2017 May 23.
Songhor is an early Miocene fossil locality in Kenya known for its diverse primate assemblage that includes catarrhine species belonging to the genera Kalepithecus, Limnopithecus, Dendropithecus, Rangwapithecus, and Proconsul. Expeditions to Songhor since the 1930s have recovered unassociated catarrhine postcranial remains from both the fore- and hindlimbs, including multiple elements from the feet. In this study, we describe KNM-SO 31233, a complete left hallucal metatarsal (Mt1), along with several other fragmentary Mt1 specimens (KNM-SO 1080, 5129, 5141, 22235). These fossils were compared to extant catarrhines and platyrrhines, as well as available fossil Miocene catarrhine Mt1s. Morphometric data were obtained from 3D surface renderings and subjected to a number of analyses to assess their phenetic affinity with the comparative sample, make predictions of body mass, and to infer their functional morphology. The size and shape of the Songhor Mt1s are diverse, exhibiting a large robust morph (KNM-SO 5141) similar in size but not in shape to extant African apes, medium-sized morphs (KNM-SO 1080, 5129 and 22235), and a smaller, slender one (KNM-SO 31233) that has a shape resembling arboreal quadrupedal leaping monkeys and suspensory atelines and hylobatids. KNM-SO 31233 is unlike other known fossil Mt1s, and in general, none of the Songhor Mt1s resembled any single extant anthropoid clade or species. The morpho-functional diversity of Songhor Mt1s is consistent with an extensive morphological and phylogenetic catarrhine diversity in the early part of the Miocene epoch.
松霍尔是肯尼亚一个中新世早期的化石地点，以其多样的灵长类动物组合而闻名，其中包括属于卡莱古猿属、湖猿属、树猿属、朗瓦猿属和原康修尔猿属的狭鼻猴类物种。自20世纪30年代以来，对松霍尔的考察已经找到了来自前肢和后肢的未关联的狭鼻猴类颅后遗骸，包括来自足部的多个部位。在这项研究中，我们描述了编号为KNM - SO 31233的完整左拇趾跖骨（Mt1），以及其他几个不完整的Mt1标本（KNM - SO 1080、5129、5141、22235）。这些化石与现存的狭鼻猴类和阔鼻猴类以及现有的中新世化石狭鼻猴类Mt1进行了比较。形态测量数据从三维表面渲染图中获取，并进行了一系列分析，以评估它们与比较样本的表型亲和力、预测体重并推断其功能形态。松霍尔Mt1的大小和形状各不相同，呈现出一种大型粗壮形态（KNM - SO 5141），其大小与现存非洲猿相似，但形状不同；中等大小形态（KNM - SO 1080、5129和22235）；以及一个较小、细长的形态（KNM - SO 31233），其形状类似于树栖四足跳跃猴以及悬猴科和长臂猿科动物。KNM - SO 31233与其他已知的化石Mt1不同，总体而言，松霍尔的Mt1没有一个与任何单一现存类人猿分支或物种相似。松霍尔Mt1的形态功能多样性与中新世早期广泛的形态和系统发育狭鼻猴类多样性相一致。
