POPULATION MESOWEAR ANALYSIS OF TAPIRUS POLKENSIS FROM THE GRAY FOSSIL SITE, TENNESSEE

Various methods exist for measuring and analyzing dental wear patterns in mammals, with a heavy emphasis on ungulates. Mesowear is a method that can be used to compare large numbers of individuals, particularly fossil individuals, and observe trends through time or between groups, and has proven useful for estimating paleoenvironmental conditions. Levels of attrition (tooth-on-tooth wear) and abrasion (tooth-on-food wear) can be readily compared by observing the shape of the cusp and relative crown height of the tooth. This study aims to use a modified method of mesowear analysis examining actual cusp angles of the population of Tapirus polkensis from the early Pliocene age Gray Fossil Site of Tennessee. Based on analyses of the fauna and flora, that site is interpreted as representing a relatively warm and humid hickory and oak-dominated forest. Crown height and cusp angle were measured for 38 tapir specimens categorized by tooth eruption series, ranging from young juveniles to old adults. Results demonstrate a strong correlation between eruption series and cusp angle, with a steady increase in mean cusp angle as individuals increase in age. A strong correlation between cusp angle and crown height was also found. The adult tapir population at Gray has a relatively low mean mesowear score, with some individuals maintaining relatively unworn crowns and sharp cusp angles into adulthood, as would be expected of a browsing species living in a relatively humid forest environment. As a mesowear analysis across all age groups for a population has not been conducted before, this study could be useful for measuring relative wear rates at different life stages and be applied across other communities.