Grant: Doctoral: Vanier Canada Graduate Scholarships

Dr. Robert Reisz, University of Toronto Jaws and teeth are essential for the survival of an animal. Teeth in particular are not only the most abundant skeletal remains in the fossil record but are unusually informative about the feeding behaviour of the extinct animals that possessed them. Normally, teeth are subject to development, growth, replacement, and different forms of wear as they interact with one another and with the food resource throughout the animal's life; however, each of these factors can be altered due to variations in environmental pressures. Therefore, there is great variety in tooth shape, size, and number of teeth within the jawbone that relates to an animal's unique feeding resources and behaviours. My research will therefore investigate the various dental adaptations and any tooth growth abnormalities for a community of extinct terrestrial vertebrates that have coexisted and evolved together to better understand the biology of these ancient animals. To do this, I will study the external surface of the jaws and teeth as well as the internal structure of the teeth by CT scanning and mechanically cutting them to examine under high magnification. I will then compare the unique dental characteristics and developmental patterns of each species to one another, as well as compare the extinct terrestrial vertebrates to living animals which have known life habits and feeding behaviours. My research is significant because it will provide key information on the initial stages of diversification of amniotes, a group that includes many fossil species as well as living mammals, birds, and reptiles. I predict the results will point to a great diversity very early in amniote evolution. Thus, I will show how the teeth of these early amniotes started the great evolutionary history that eventually led to amniotes living today.