Graduate student Maria Cole, with direction from faculty advisor William Jungers, is studying quantitative aspects of skeletal size and shape and effects on locomotor adaptations in the vertebrate group Ceratomorpha (Mammalia, Perrissodactyla) which includes the living tapirs and rhinoceroses and a diverse radiation of now extinct relatives, known from extensive fossils. Postcranial variation will be examined with respect to differences in body size, ecology and relative phylogenetic relationship. Ceratomorphs present an ideal case for assessing variation in locomotor anatomy with respect to these interrelated and often confounding factors. Because of enormous variation in body size (ceratomorphs include the largest known land mammals in the fossil to investigate the more general question of the mechanical basis for patterns of mammalian size-scaling. Analysis of external size and shape will be supplemented by cross-sectional geometric data (second moment of area, section moduli, cortical area) derived from computed tomography. Special attention will also be paid to long bone curvature, mechanical advantages of extensor muscles, and articular size and shape. These data and analyses will provide new insights into the functional anatomy and paleobiology of ceratomorphs specifically and should contribute to our understanding of general principles governing diversity of structural design in the mammalian locomotor system.
