| Description |
Squamate reptiles are ideal subjects for investigating relationships between diet and dentition patterns because they exhibit wide dietary diversity and taxonomic abundance. Most previous research is qualitative and limited to a basic assessment of the influence diet has on dentition (Hotton, 1955; Montanucci, 1968; Presch, 1974; Evans et al., 2007; Melstrom, 2017). Quantitative studies of squamate dentition have shown that carnivores generally possess simple teeth, whereas herbivores possess more complex teeth (Melstrom, 2017). Despite this pattern being well documented in both mammals and reptiles, specific patterns of squamate dental complexity remain largely unknown. Here, I use quantitative methods to re-examine the relationship between dentition and diet. Additionally, I expand upon previous work to examine complexity differences between dental elements and test the hypothesis that there are dentitional shifts in dental complexity through ontogeny. I molded and cast juvenile, sub-adult, and adult extant lizard dentitions, generated high-resolution CT-scans, and analyzed 3D models with a geographic information system application called SurferManipulator. I calculated the surface complexity of teeth using orientation patch count rotated (OPCR), which generates tooth complexity values based on pixel orientation. My findings corroborate previous research by showing that species consuming more plant material possess more complex teeth. I did not find significant complexity differences between the left and right side of the mouth nor the upper and lower tooth row, with the exception of Amblyrhynchus cristatus, the marine iguana, which possesses significantly more complex dentary teeth than maxillary teeth. Regarding dentitional change through ontogeny, I unexpectedly found conflicting species patterns. Amblyrhynchus cristatus, which is herbivorous throughout its lifetime, increases dental complexity through ontogeny, whereas Ctenosaura, which is generally insectivorous as juveniles and herbivorous as adults, decreases dental complexity. This research is important because it quantifies specific patterns of squamate dental complexity that have otherwise not been observed. |
