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Author: Blue, Kathleen Teresa Brundrett
Awarding University: University of Chicago, USA
Level : PhD
Holding Libraries: University Microfilms International ;
Victoriapithecus macinnesi represents the earliest best-known old world monkey. Recovered from sediments on Maboko Island, Kenya dated to &sim <coded data>;15 ma, victoriapithecus antedates the split between the two extant old world monkey subfamilies (Von Koenigswald 1969; Leakey 1985; Benefit and Pickford 1986; Benefit 1987, 1993; Harrison 1987, 1989; Benefit and Mccrossin 1993). The large sample of forelimb fossils (n = 216) and phalangeal specimens (n = 268) attributed to victoriapithecus provides the basis for my analysis of the morphology of the forelimb. Statistical analysis indicates that the Maboko cercopithecoid sample represents a single species, albeit one with significant intraspecific variation. Victoriapithecus macinnesi from Maboko represents a single species of an early cercopithecoid characterized by habitual terrestriality best suited to a woodland environment. Morphological affinities are closest to extant cercopithecines, although some semblance of characters last shared with the common ancestor of both new and old world monkeys is retained. (Abstract shortened by UMI.) This dissertation includes a cd that is multimedia (contains text and other applications not available in printed format). The cd requires the following system application: internet browser.
Author: Benefit, Brenda Regina
Awarding University: New York University, USA
Level : PhD
Holding Libraries: University Microfilms International ; National Council for Science and Technology Library ;
Dental and cranial specimens of victoriapithecus collected by Martin Pickford at the middle miocene site of Maboko Island in western Kenya from 1982-1984 are described within this dissertation. Delson's interpretation of the maboko monkeys as representing two species, one at or near the origin of colobinae and the other of cercopithecinae, is rejected. Instead, it is concluded that only one species is present at maboko Victoriapithecus macinnesi on the basis of the distribution of non-metric features such as the crista obliqua and 'hypoconulid' along the molar row, and comparison of metric variation within the maboko sample of monkeys to variation measured in extant and paleospecies. Univariate and multivariate discriminate analyses demonstrate that the molars of Victoriapithecus macinnesi differ phenetically from those of monkeys of modern aspect. Colobines and cercopithecines share derived dental features, including the alignment of the long axis of lower p4 parallel to that of the molar row and complete loss of both the crista obliqua and 'hypoconulid', that they do not share with V. Macinnesi. Based on phenetic and cladistic evidence, V. Macinnesi is placed into the family victoriapithecidae to denote its distinction from colobinae and cercopithecinae which are more closely related to each other than either is to the early monkeys. The origin of bilophodonty in monkeys is associated here with an increased capacity relative to early catarrhines for puncturing and crushing hard fruits or seeds rather than for shearing. Compared to extant monkeys, V. Macinnesi is reconstructed as having been highly frugivorous. The divergence and diversification of colobine and cercopithecine monkeys is discussed from the perspective of dietary reconstructions based on shear crest length and tooth wear for fossil species, and their evolution from a frugivorous ancestor.