<i>Proconsul heseloni</i> Feet from Rusinga Island, Kenya
Open Access
- Author:
- Dunsworth, Holly M.
- Graduate Program:
- Anthropology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 12, 2006
- Committee Members:
- Alan Walker, Committee Chair/Co-Chair
Joan Therese Richtsmeier, Committee Member
John Henry Challis, Committee Member
George Robert Milner, Committee Member - Keywords:
- Metatarsal
Cross-sectional geometry
Kaswanga Primate Site
Hominoid
Paleoanthropology - Abstract:
- In the mid 1980s, teams from Johns Hopkins University and the National Museums of Kenya colleted a minimum of ten <i>Proconsul heseloni</i> individuals from the Kaswanga Primate Site (KPS), Rusinga Island, Kenya. Five of them have nearly complete right and/or left feet. The preservation and anatomy of the KPS tarsals and metatarsals are described and analyzed here. Bivariate and multivariate analyses of the linear proportions of the feet and hindlimbs of the individuals illuminate arboreal characteristics in the <i>Proconsul</i> foot. Because the KPS individuals died at different stages of development, their foot and hindlimb proportions through ontogeny are investigated. Comparative cross-sectional ontogenetic samples include 222 <i>Pan troglodytes</i>, 65 <i>Gorilla gorilla gorilla</i>, and 115 <i>Macaca mulatta</i> and adult samples include 15 <i>Pan paniscus</i>, 24 <i>Colobus</i> (<i>angolensis, guereza</i>, and <i>badius</i>), 10 <i>Nasalis proboscis</i>, and 12 <i>Hylobates lar</i>. <i>Proconsul</i> aligned with <i>Colobus</i> and <i>Nasalis</i> in overall proportions and with apes in certain metatarsal proportions. Dissimilarities to macaques and similarities to apes in growth patterns suggest <i>Proconsul</i> was not born with large feet like macaques and other non-hominoid primates. Thus, <i>Proconsul</i> may have shared life history traits with <i>Pan</i> and <i>Gorilla</i> like increased altriciality in infant locomotor and positional behaviors. In order to investigate strength properties of the metatarsals, the midshafts of a total of 29 <i>Proconsul</i> metatarsals from six individuals were scanned with high-resolution microCT. Biplanar radiography and the latex cast method were used to obtain cross-sectional properties of the metatarsals from an extant cross-sectional ontogenetic sample of 52 <i>Macaca mulatta</i> (260 metatarsals) and 74 <i>Pan troglodytes</i> (370 metatarsals). Regression plots showed much closer similarity between <i>Proconsul</i> and <i>Macaca</i> than <i>Proconsul</i> and <i>Pan</i> in overall strength properties and cross-sectional shapes when normalized for metatarsal length and for body size. However, the first metatarsal of <i>Proconsul</i> showed greater resistance to bending and torsional forces for its length than <i>Macaca</i>, which is more like <i>Pan</i>. Overall results support previous interpretations on partial and incomplete <i>Proconsul</i> pedal fossils, and on other parts of the postcranial skeleton, that <i>Proconsul</i> was a generalized arboreal quadruped that grasped tree branches with a long, strong hallux.