A biomechanical analysis of the masticatory apparatus of Ptilodus (Multituberculata)

This study investigates the biomechanics of dental function in Ptilodus (Multituberculata) through vector analysis of masticatory muscles and comparisons of mechanically relevant cranial and dental dimensions to extant functional analogues. To isolate function, feeding behavior is divided into incision, slicing-crushing, and grinding, and these activities are related to corresponding dental regions (incisors, premolars, and molars, respectively). Quantitative comparisons to living mammals are made with respect to inferred muscle vectors. The masticatory apparatus of Ptilodus appears to have been adapted for a variety of jaw movements, including powerful retraction during the grinding cycle (utilizing the posterior part of the temporalis muscle), and the generation of large bite forces at a variety of tooth positions. The lateral compression of p4 is one indication that resistant food objects were a dietary component. However, the size and orientation of the posterior surface of the mandibular condyle indicates an upper size limit of approximately 10 mm for relatively resistant items. The size and arrangement of the bony and muscular structures indicate that the masticatory apparatus was potentially versatile and, thus, that Ptilodus and, by inference, other multituberculates, were probably omnivorous. © 1992 by the Society of Vertebrate Paleontology.

Duke Scholars

Author Christine Elizabeth Wall Evolutionary Anthropology