BALKE, M.J.; MAGLIA, A.M.; University of Missouri- Rolla; University of Missouri- Rolla: Comparative Morphology of the Anuran Nasal Capsule

The nasal capsule of frogs is a highly complex, but poorly known morphological assembly. Because the cartilages of the capsule are difficult to identify using traditional methods of dissection and/or clearing-and-staining, they are rarely described. Thus, the nasal morphology of only a few species is known in any detail. The elements of the nasal capsule are important in that they provide support to the olfactory apparatus and the vomeronasal organ, they help close the nares during diving, and they depress to reduce buccal cavity volume during swallowing. Because of their many functions, we might expect that nasal morphology is highly constrained. However, comparisons of the capsules of species for which the morphology is known suggest that their structures are highly variable. Herein, we compare the nasal apparatus of several families of frogs (including bominatorids, pelobatids, pelodytids, pipids, ranids, hylids, and bufonids) using both traditional methods and 3D digital reconstructions (archived in the MorphologyNet digital library, http://www.morphologynet.org). We comment on structures that are conserved throughout frogs, identify structures that are highly variable, and discuss the possible functional implications of differences. We also note the potential phylogenetic utility of the information we assembled.