1. Tooth shape is the result of a constant struggle between the goals of fracturing food and defending against tooth fracture. Teeth lie at the interface between an animal and its food, delivering the energy required to mechanically process the food. Animal dentition is a key system for exploring interactions between levels of biological inquiry: genetic, developmental, morphological, functional and dietary. I study the morphology of tooth shape through the lens of fracture/cutting mechanics, which quantifies how energy is delivered and creates fractures in materials. I developed an experimental cutting device resembling a guillotine that is used to measure the energetics of cutting biological tissues with different tooth shapes (Fig. 1). My work has shown that common dental morphologies (i.e. V-shaped blades found in mammals, archosaurs, birds and fish) act as highly efficient cutting tools (Anderson & LaBarbera 2008; Anderson 2009a). I have combined this experimental work with finite element analysis (FEA), an engineering approach that visualizes the stress and strain within the objects being cut in the experiments. Using these combined methods, I have shown that tooth morphology specifically controls the deformation of food items to reduce energy expenditure during chewing (Anderson & Rayfield 2012, Royal Society Interface). I have also examined how dental morphology affects the ability of a tooth to resist breakage during food processing. FEA on tooth form has shown that the mammalian cingulum (a ridge of enamel ringing the base of the tooth) acts as a strain dampener, preventing certain types of enamel breakage (Anderson et al. 2010).