Ungar, Peter S. and Sues, Hans-Dieter. 2019. "Tetrapod Teeth: Diversity, Evolution, and Function." In Feeding in Vertebrates: Evolution, Morphology, Behavior, Biomechanics. Bels, Vincent and Whishaw, Ian Q., editors. 385–429. Cham: Springer International Publishing. In Fascinating Life Sciences.
Teeth provide an excellent model system for understanding evolutionary change and how it has led to adaptive diversity across tetrapods. Their durability over geological timescales and their ubiquity in the fossil record make teeth unique and allow direct comparison of dental structure for both extant and extinct species. We can detail diversity of size, shape, and structure, past and present, and in doing so explore what nature can accomplish with a little embryonic tissue and some signaling proteins—common and novel solutions to the problems of food acquisition and processing. Teeth are especially important for understanding the process of evolution because of their central role in ecology; eater to eaten is the most fundamental relationship between living organisms. Teeth mediate this relationship, and so are the front line in nature’s “struggle for existence.” This chapter presents a survey of dental form and function in both stem- and crown-tetrapods. Each of the major groups—Amphibia, Reptilia, and Mammalia and their stem-groups—is considered separately. We begin with a general discussion of how teeth work, focusing on their roles in food acquisition and processing. We then review distinctive dental forms for extinct and extant taxa, group by group, to give the reader a sense of the extraordinary range of adaptive solutions among the tetrapods to the challenges associated with food acquisition and processing. Our survey culminates with an overview of the origin, evolution, and adaptive radiation of the mammalian masticatory system.
