Evolutionary morphology of the postcranial skeleton in Afro -Malagasy Tenrecoidea (Mammalia).
Item
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Title
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Evolutionary morphology of the postcranial skeleton in Afro -Malagasy Tenrecoidea (Mammalia).
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Identifier
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AAI3187430
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identifier
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3187430
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Creator
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Salton, Justine A.
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Contributor
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Adviser: Frederick S. Szalay
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Date
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2005
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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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Biology, Zoology | Biology, Anatomy | Biology, Ecology
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Abstract
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The 26+/- extant species of small mammals in Tenrecoidea live in a diverse range of microhabitats, primarily in Madagascar, and provide an excellent model for exploring the adaptive and phylogenetic significance of skeletal form. This study is a descriptive and quantitative morphological assessment of the tenrecoid skeleton with a focus on postcranial elements and identification of habitus- and heritage-related characters. 273 specimens from ten genera of Tenrecoidea and three outgroups (Macroscelididae, Erinaceidae, and Solenodontidae) were studied and digitally imaged for acquisition of two-dimensional landmark data. Results were evaluated in an ecological and evolutionary framework; features were assessed in the context of known positional behaviors and tested against current phylogenetic hypotheses.;Comparisons of the Tenrecinae and Oryzorictinae postcranium indicated a basic difference in postural behavior between the two major subfamilies, which was confirmed by observations of live animals during field study in Madagascar. The tenrecine hindlimb is more habitually laterally abducted, and more multiaxially mobile than that of the oryzorictines, as reflected at the hip, knee, and upper ankle joints. Despite their superficial similarities, Echinops and Setifer exhibit a series differences based on arboreal locomotor behavior in the former and more terrestrial behavior in the latter. Oryzorictes has a suite of postcranial adaptations related to its subterranean microhabitat, but these are distinct from those of Hemicentetes, illustrating their different digging-styles and independent acquisition of digging-related traits. Although Microgale cowani is not known to be a digger, it shares a series of characters with Oryzorictes, and most likely has a more fossorial lifestyle than previously recorded. Although Limnogale and Potamogale share postcranial adaptations for swimming behaviors, few characteristics are similar between the two. Limnogale is most likely part of the oryzorictine clade, leaving the Malagasy Tenrecidae as an intact monophyletic taxon. A family-level potamogalid status is supported. Solenodontids, macroscelidids, and erinaceids are considered as tenrecoid outgroups and higher-level eutherian phylogeny is discussed. Finally, I present a preliminary overview of the tenrecoid skull, axial skeleton, and cross-sectional geometry of the humerus and femur with recommendations for future work.
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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.
