Armed to the teeth: Supplementary material, R code, Rdata, mesh, landmarks

The structure, composition, and shape of teeth have been related to
dietary specialization in many vertebrate species, but comparative studies
on snakes’ teeth are lacking. Yet, snakes have diverse dietary habits that
may impact the shape of their teeth. We hypothesize that prey properties,
such as hardness and shape, as well as feeding behavior, such as aquatic
or arboreal predation, or holding vigorous prey, impose constraints on the
evolution of tooth shape in snakes. We compared the morphology of the
dentary teeth of 63 species that cover the phylogenetic and dietary
diversity of snakes, using 3D geometric morphometrics and linear
measurements. Our results show that prey hardness, foraging substrate, and
the main foraging mechanical challenge are important drivers of tooth
shape, size, and curvature. Overall, long, slender, curved teeth with a
thin layer of hard tissue are observed in species that need to maintain a
grip on their prey.  Short, stout, less curved teeth are
associated with species that undergo high or repeated loads. Our study
demonstrates the diversity of tooth morphology in snakes and the need to
investigate its underlying functional implications to better understand
the evolution of teeth in vertebrates.