Presenter(s): Caitlyn Boatman – Biology
Faculty Mentor(s): Samantha Hopkins
Poster 54
Research Area: Biology
Animals that maintain constant internal body temperatures have high energy requirements. In a resource limited ecosystem, efficient food processing is vital to ensure that these animals extract enough energy from their food to heat their bodies. Tooth size and shape, along with the precise contact between top and bottom teeth (occlusion), are adaptations that allow for efficient food processing. Because of this relationship between energy extraction and tooth function, the size of those teeth with precise occlusion are often highly conserved in terrestrial species like bears and foxes. Some work has been done on studying dental variation in terrestrial animals with precisely occluding cheek teeth, such as the carnassial pair in some carnivores. However, few studies have investigated dental variation in aquatic carnivores with homodont (homogenous), non-occluding cheek teeth. To fill this gap, I investigated dental variation in pinnipeds, a clade of aquatic carnivores with homodont (identical) cheek teeth that are not used for processing food. Studying these species allowed me to determine if various measures of tooth size are conserved in species that swallow their food whole. Specifically, I examined how tooth number, individual tooth area and size, total tooth area, tooth row length, and shearing-blade length vary within species, across species, and across families in clade pinniped. I used the program ImageJ to make my measurements. I determined that variation is high in pinniped dentition compared to the dentition of terrestrial mammals. These results suggest that tooth shape and size are not evolutionary constrained in pinnipeds.