DeSilva Jeremy, Shoreman Eleanor, MacLatchy Laura
Department of Anthropology, University of Michigan, Ann Arbor, MI 48109-1107, USA.
J Hum Evol. 2006 Jun;50(6):687-95. doi: 10.1016/j.jhevol.2006.01.008. Epub 2006 Mar 6.
The external morphology of a fragmentary right proximal femur from southwestern Uganda is described here. Discovered in the Kikorongo Crater of Queen Elizabeth National Park in 1961, this specimen was informally assigned to Homo sapiens (although never described) and tentatively dated to the late Pleistocene. However, because aspects of the external morphology of the femur align the fossil with the African great apes, we suggest that the Kikorongo femur may be the first postcranial fossil of the genus Pan. Like the African apes, the Kikorongo specimen lacks both an obturator externus groove and an intertrochanteric line. It has a short femoral neck with a circular cross section, and a narrow and deep superior notch. Using resampling statistics and discriminant function analysis, the Kikorongo femur clustered with the genus Pan, as opposed to Gorilla or Homo. However, if the specimen is from Pan, it would be large for this taxon. Furthermore, features that clearly distinguish the external morphology of Plio-Pleistocene hominin proximal femora from African ape femora, such as the shape of the femoral neck in cross section and femoral neck length, have converged in Holocene humans and African apes. Unfortunately, the internal morphology of the femoral neck of the Kikorongo fossil was not discernable. Although we hypothesize that the Kikorongo femur is from the genus Pan, there is such variability in the proximal femora of modern humans that, although it would be an unusual human, it remains possible that this fossil represents H. sapiens.
本文描述了来自乌干达西南部的一段残破的右股骨近端的外部形态。该标本于1961年在伊丽莎白女王国家公园的基科龙戈火山口被发现，当时被非正式地归类为智人（尽管从未被描述过），并初步定为晚更新世。然而，由于股骨的外部形态特征使该化石与非洲大猿相符，我们认为基科龙戈股骨可能是黑猩猩属的第一块颅后化石。与非洲猿类一样，基科龙戈标本既没有闭孔外肌沟也没有转子间线。它的股骨颈短，横截面呈圆形，有一个狭窄且深的上切口。通过重采样统计和判别函数分析，基科龙戈股骨与黑猩猩属聚类，而不是与大猩猩属或智人属。然而，如果该标本来自黑猩猩属，对于这个分类单元来说它会很大。此外，上新世 - 更新世人类近端股骨与非洲猿股骨在外部形态上的明显区别特征，如股骨颈横截面的形状和股骨颈长度，在全新世人类和非洲猿类中已经趋同。不幸的是，基科龙戈化石股骨颈的内部形态无法辨认。尽管我们假设基科龙戈股骨来自黑猩猩属，但现代人类近端股骨存在如此大的变异性，以至于尽管它可能是一个不寻常的人类个体，但这块化石仍有可能代表智人。
