Meeting Abstract
Lingually hinged teeth are useful for sit-and-wait ambush predators, such as the goosefish Lophius americanus. They bend inward to allow prey to be easily pulled into the mouth, but their limited forward bending prevents prey from escaping. In this study, we use illustrations, photographs, and tooth measurements to document the hinging mechanism in Lophius americanus. The hinged teeth of Lophius are not ankylosed to the jaw, and the base of the tooth sits on a semicircular tooth pedestal protruding from the jaw bone. Points of occlusion between the tooth and this pedestal act as the fulcrum of the tooth lever system, although the position of the fulcrum is different in backward and forward bending. In lingual bending, the tooth can be pushed back on the lingual fulcrum with very little effort. In labial bending, the pedestal and tooth have interlocking grooves for stability at the labial fulcrum point, and an inelastic ligament prevents labial bending past this occlusal surface. These morphological features form a “locking” mechanism, which requires substantial force (greater than 27.3 N) to overcome. Additionally, some Lophius teeth are ankylosed to the jaw, allowing for comparisons of both hinged and unhinged tooth types within the same individuals. We found that ankylosed teeth are smaller and less variable in size compared to the hinged teeth, although they overlap in size. We are also applying techniques such as micro-CT, mechanical testing, and histological sectioning to add to our understanding of the anatomy and function of these teeth.
