A fossil hominoid proximal femur from Kikorongo Crater, southwestern Uganda

• Published in: Journal of human evolution Vol. 50; no. 6; pp. 687 - 695
• Main Authors: DeSilva, Jeremy, Shoreman, Eleanor, MacLatchy, Laura
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2006; Elsevier
• Subjects: Animals; Anthropometry; Ape fossil; Discriminant Analysis; Environmental studies; Fauna; Femur - anatomy & histology; Fossils; Gorilla; Hominid; Hominidae - anatomy & histology; Hominidae - classification; Hominoid; Human paleontology; Humans; Metal industry; Methodology and general studies; Neanthropus; Pan; Prehistory and protohistory; Proximal femur; Reference Values; Resampling; Typology, technology and attribute analysis; Uganda; Bronze Age; Uganda; Africa; Ape fossil; Proximal femur; Uganda; Hominoid; Pan; Resampling; Hominid; Gorilla; Cluster analysis; Femur; Late Pleistocene; Hominoïds; Cross; Fauna; Crater; Notch; Homo sapiens; Statistics; Discriminant Analysis; Function; Morphology; Ape; Holocene
• ISSN: 0047-2484; 1095-8606
• DOI: 10.1016/j.jhevol.2006.01.008

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.