The peccaries (Artiodactyla: Tayassuidae) are a family of ungulates with extreme specializations of the nasal passages. In particular, their noses contain a complex of inflated bony structures found nowhere else among the mammals. The functions of these structures are completely unknown. One difficulty in arriving at a functional interpretation is that little is known about the functional morphology of the vertebrate respiratory system. The proposed research is both a systematic investigation of possible functions of the peccary nasal apparatus and general analysis of mammalian respiratory mechanics. The principal investigators will test the hypothesis that the peccary structures are involved in olfaction by histological and ultrastructural study of the nasal epithelia. They will assess whether the structures function as part of a brain-cooling mechanism by elucidating the anatomy of the nasal vasculature. They will use mathematical modeling and an experimental flow apparatus to test whether the structures are associated with a mechanism for exchanging heat or water with the environment, and also to investigate if they could be used to remove particles from a dust-laden atmosphere.
