Variation in Pinniped Dentition

Abstract

I studied variation in the teeth of 5 different species of pinniped: E. jubatus, Z. californianus, P. vitulina, E. barbatus, and O. rosmarus. Prior to this study, little work had been done on dental variation in marine mammals with homodont teeth. Most studies have looked specifically at terrestrial carnivores such as C. lupus and F. silvestris. Specifically, I compared the coefficient of variation of a few different aspects of dentition (total surface area, individual tooth surface area, toothrow length, tooth width and blade length) and compared them to CVs of other published terrestrial mammals. In general, I determined that pinniped dentition was much more variable than dentition of terrestrial species (i.e. had higher CVs). In addition, I determined that blade length, toothrow length, and total surface area is correlated with body size. Larger bodied animals or species have larger surface areas, toothrow lengths, and blade lengths. Even when normalized for body size, variation in mean sizes of each of these aspects persisted, suggesting there is no ideal toothrow length, blade length, or total tooth surface area needed for survival.