Cote Susanne, Werdelin Lars, Seiffert Erik R, Barry John C
Department of Anthropology and Peabody Museum, Harvard University, Cambridge, MA 02138, USA.
Proc Natl Acad Sci U S A. 2007 Mar 27;104(13):5510-5. doi: 10.1073/pnas.0700441104. Epub 2007 Mar 19.
Kelba quadeemae, a fossil mammal from the Early Miocene of East Africa, was originally named on the basis of three isolated upper molars. Kelba has previously been interpreted as a creodont, a pantolestid, an insectivoran, and a hemigaline viverrid. The true affinities of this taxon have remained unclear because of the limited material and its unique morphology relative to other Miocene African mammals. New material of Kelba from several East African Miocene localities, most notably a skull from the Early Miocene locality of Songhor in Western Kenya, permits analysis of the affinities of Kelba and documents the lower dentition of this taxon. Morphological comparison of this new material clearly demonstrates that Kelba is a member of the order Ptolemaiida, a poorly understood group whose fossil record was previously restricted to the Oligocene Fayum deposits of northern Egypt. Phylogenetic analysis supports the monophyly of the Ptolemaiida, including Kelba, and recovers two monophyletic clades within the order. We provide new family names for these groups and an emended diagnosis for the order. The discovery of ptolemaiidans from the Miocene of East Africa is significant because it extends the known temporal range of the order by >10 million years and the geographic range by >3,200 km. Although the higher-level affinities of the Ptolemaiida remain obscure, their unique morphology and distribution through a larger area of Africa (and exclusively Africa) lend support to the idea that Ptolemaiida may have an ancient African origin.
凯尔巴·夸德马埃是一种来自东非早中新世的化石哺乳动物，最初是根据三颗孤立的上臼齿命名的。凯尔巴此前被解释为肉齿目动物、泛兽科动物、食虫目动物和半鼬科灵猫科动物。由于材料有限以及其相对于其他中新世非洲哺乳动物独特的形态，这个分类单元的真正亲缘关系一直不清楚。来自东非几个中新世地点的凯尔巴新材料，最著名的是来自肯尼亚西部松霍尔早中新世地点的一个头骨，使得对凯尔巴的亲缘关系进行分析并记录该分类单元的下齿列成为可能。对这些新材料的形态学比较清楚地表明，凯尔巴是托勒密目动物的一员，这是一个了解甚少的类群，其化石记录以前仅限于埃及北部渐新世的法尤姆沉积层。系统发育分析支持包括凯尔巴在内的托勒密目的单系性，并在该目中发现了两个单系分支。我们为这些类群提供了新的科名，并对该目进行了修订后的诊断。从东非中新世发现托勒密目动物具有重要意义，因为它将该目的已知时间范围延长了超过1000万年，地理范围扩大了超过3200公里。尽管托勒密目的高级亲缘关系仍然模糊不清，但它们独特的形态以及在非洲更大区域（且仅在非洲）的分布支持了托勒密目可能起源于古老非洲的观点。
