Form, function, and allometry of the cercopithecid foot.
Item
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Title
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Form, function, and allometry of the cercopithecid foot.
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Identifier
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AAI9009790
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identifier
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9009790
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Creator
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Strasser, Elizabeth.
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Contributor
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Adviser: Eric Delson
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Date
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1989
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Language
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English
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Publisher
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City University of New York.
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Subject
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Anthropology, Physical
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Abstract
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The goal of this dissertation was to determine the mechanical basis for some distinctive proportional differences in the hindlimb skeleton, especially the foot, of cercopithecid monkeys. Proportional differences were the focus of study because they have occupied a central position in the description of the cercopithecid hindlimb. Many proportions describe morphological, not mechanical, units. Consequently, interpreting their mechanical significance was difficult. In order to determine the mechanical significance of the dimensions comprising the proportions, biomechanical models were utilized. The choice of biomechanical models was dependent upon frequency data, culled from the literature, which documented positional activities of cercopithecids in the wild. The major modes of locomotion utilized by cercopithecids involved pronograde arboreal quadrupedalism, terrestrial cursorial quadrupedalism, leaping and climbing.;The fifty cercopithecid species examined in this study range in average body mass from 1.5 to 28.5 kg. Because the absolute size of an organism will affect the relative proportions of its musculoskeletal system, the scaling of the dimensions comprising hindlimb and pedal proportions were examined.;Four major conclusions were reached. (1) The hindlimb and foot segment dimensions scale with body mass to maintain mechanical similarity among locomotor groups. Therefore, indices which describe the relative lengths of the lever arms for muscle groups around the knee, talocrural and metatarsophalangeal joints all decrease with an increase in body mass. The majority of traditional indices which described the foot in cercopithecids revealed differences which were primarily a function of size. (2) The major adaptation of terrestrial cercopithecines in the features analysed was reduction in the length of the phalanges due to the assumption of digitigrady. Theropithecus and Erythrocebus also have a high crural index relative to their body mass. (3) Colobines have elongated the hindlimb, probably to enhance leaping. Colobines are also characterized by a distinctive pseudo-artiodactyl condition of the digits, as well as elongated phalanges. (4) Dramatically shortened limbs in Macaca fuscata and M. thibetana suggest that thermal conditions have as profound an effect on the lengths of the hindlimb segments, relative to body mass, as do adaptations to particular locomotor modes.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
