Evolutionary and Functional Morphology of the Mammalian Skull

Christopher J. Vinyard, Ph.D.

Assistant Professor
Department of Anatomy

Northeastern Ohio Universities College of Medicine 4209 St. Rt. 44, P.O. Box 95 Rootstown, Ohio 44272-0095 Phone: (330) 325-6279 Fax: (330) 325-5913 Email: cvinyard@neoucom.edu

Education:

Professional Experience:

Research Interests:

My research aims to understand the relationships between the form, function and evolution of the primate head. Specifically, I aim to better understand how specific activities, such as chewing or biting, affect the form and evolution of the primate skull and face. Most of this work is question driven and falls into one of three research avenues: 1) Physiology and functional morphology, 2) Behavioral and ecological morphology and 3) Comparative morphometrics.

A major component of my research involves studying the physiology of chewing and biting behaviors. This involves using in vivo methods, such as electromyography, strain gage approaches and video analysis, to study jaw-muscle activity patterns, facial bone strains and jaw movements during chewing and biting in living animals. Recently, we have been conducting two projects. The first focuses on describing the jaw mechanics during tree gouging in the South American common marmoset (Callithrix jacchus). The second describes how the jaw muscles are recruited during chewing in lemurs, monkeys and treeshrews. This work is done in collaboration with Christine Wall, Kirk Johnson, Susan Williams and Bill Hylander.

A second research focus involves conducting field studies of primate chewing and biting behaviors. In addition to allowing me to assess how well our lab research mimics natural field conditions, this work provides an environmental context for interpreting morphological adaptations in the primate head. Recent field work includes studying the mechanics of tree gouging by common marmosets at the Estação Ecológica do Tapacurá, Brasil and studying the ecological morphology of dietary segregation among three sympatric bamboo lemurs in Ranomafana National Park, Madagascar. The fieldwork is done in collaboration with Maria A. O. Monteiro da Cruz, Mônica Montenegro, Leonardo Melo,Yumma Valle, Peter Lucas, Nayuta Yamashita and Chia Tan.

Finally, I am interested in comparative analyses of skull and jaw-muscle form among primate species. These comparative studies complement the lab and field research by broadly describing patterns of form-function associations and morphological integration among species and/or age-groups. Recently, we have been comparing skull and jaw-muscle form in tree-gouging primates to closely-related non-gouging species. This work is done in collaboration with Andrea Taylor, Christine Wall, Susan Williams and Bill Hylander.

Selected Publications:

• Vinyard C.J. and M.J. Ravosa (1998) Ontogeny, function and scaling of the mandibular symphysis in papionin primates. J. Morphol. 235:157-175.

• Payseur B.A., Covert H.H., Vinyard C.J. and M. Dagosto (1999) New body mass estimates for Omomys carteri, a Middle Eocene primate from North America. Am. J. Phys. Anthropol.109:41-52.

• Ravosa M.J., Vinyard C.J., Gagnon M. and S.A. Islam (2000) Evolution of anthropoid jaw loading and kinematic patterns. Am. J. Phys. Anthropol. 112:493-516.

• Vinyard C.J. and F.H. Smith (2001) Morphometric testing of structural hypotheses of the supraorbital region in modern humans. Z. Morphol. Anthropol. 83:23-41.

• Ravosa M.J. and C.J. Vinyard (2002) On the interface between ontogeny and function. In Plavcan J.M., Kay R.F., Jungers W.L. and C.P. van Schaik (eds.) Reconstructing Behavior in the Primate Fossil Record. New York: Plenum Press. pp 73-111.

• Williams S.H., Wall C.E., Vinyard C.J. and W.L. Hylander (2002) A biomechanical analysis of skull form in gum-harvesting galagids. Folia Primatol. 73:197-209.

• Vinyard C.J., Wall C.E., Williams S.H. and W.L. Hylander (2003) A comparative functional analysis of the skull morphology of tree gouging primates. Am. J. Phys. Anthropol.120:153-170.

• Kay R.F., Schmitt D., Vinyard C.J., Perry J.M.G., Shigehara N., Takai M. and Egi N. (2004) The paleobiology of Amphipithecidae, South Asian late Eocene primates. J. Hum. Evol.46:3-24.