Meeting Abstract
The vomer is an important tooth-bearing cranial bone in the lungless salamanders (Plethodontidae) that displays different morphologies according to the feeding environment of the adult. Aquatic-feeding salamanders present vomerine tooth rows parallel with the maxillary teeth that are thought to help grasp prey while expelling water from the mouth. Terrestrial-feeding adults retain the parallel row from the larval state but extend the tooth row posteriorly, forming an L-shape, so that the teeth may help bring prey down the throat. However, the overall morphology of the vomer itself appears to vary taxonomically rather than by habitat. To study these two influences on vomerine shape, we examined species of the morphologically diverse subfamily Spelerpinae, in which two of the five genera (Eurycea and Gyrinophilus) present both aquatic and terrestrial species. 3D data were collected using micro computed tomography (microCT) scans from specimens from the Field Museum of Natural History and the Illinois Natural History Survey, representing four of the five Spelerpinae genera. Geometric morphometric (GM) analyses were performed to capture shape variation of both the vomer and the vomerine tooth row, using a combination of landmarks and semi-landmarks. Results show multiple influences on vomer shape variation in both aquatic and terrestrial taxa, with taxonomic position showing larger influence in terrestrial taxa.
