Functional Morphology and Symmetry in the Odontocete Ear Complex.

ABSTRACT

Odontocete ear complexes or tympanoperiotic complexes (TPCs) were compared for asymmetry. Left and right TPCs were collected from one long-beaked common dolphin (Delphinus capensis) and one Amazon River dolphin (Inia geoffrensis). Asymmetry was assessed by volumetric comparisons of left and right TPCs and by visual comparison of superimposed models of the right TPC to a reflected mirror image of the left TPC. Kolmogorov-Smirnov tests were performed to compare the resonant frequencies of the TPCs as calculated by vibrational analysis. All analyses found slight differences between TPCs from the same specimen in contrast to the directional asymmetry in the nasal region of odontocete skulls.