Meeting Abstract

P3.141  Sunday, Jan. 6  Comparison of Nasal Turbinal Surface Area in Caniform and Feliform Carnivorans PANG, B*; GREEN, P; BIRD, D; HALPERN, Z; CURTIS, A; VAN VALKENBURGH, B; University of California,Los Angeles; University of Massachusetts Amherst; University of California,Los Angeles; University of California,Los Angeles; University of California,Los Angeles; University of California,Los Angeles benisonp@gmail.com

The nasal cavity of mammals houses a complex set of bones known as turbinals that are involved in olfaction and respiration.In long snouted species,such as canids,the two functions are largely spatially separated.Olfactory epithelium is confined to the posterior ethmoturbinals and dorsal nasoturbinals,while respiratory epithelium is located on the anterior maxilloturbinals within the respiratory pathway.In short-snouted species,the separation is less distinct,with ethmoturbinals overlapping maxilloturbinals.We studied the scaling of maxilloturbinal and ethmoturbinal surface area (SA) with body size in caniform and feliform carnivorans to determine whether the latter exhibit reduced maxilloturbinal SA.Using CT scans and 3-D visualization software,we measured turbinal surface area in 22 caniform and 13 feliform species and found that feliforms have less maxilloturbinal SA and more ethmoturbinal SA than caniforms.This might indicate greater olfactory abilities in feliforms,but not if anterior ethmoturbinals are co-opted for respiratory function.Visual inspection of the 3-D models suggest that this is the case.After correcting for skull length,we found that the hypothesized recruitment of ethmoturbinals occurs to a greater extent in short-faced feliforms,possibly due to reduced nasal chamber volume.Among the feliforms,the spotted hyena (Crocuta crocuta),brown hyena (Parahyaena brunnea) and striped hyena (Hyaena hyaena)are similar to large canids in having an exceptionally large ethmoturbinal surface area.This could reflect expanded home range size as well as intense scent marking behavior,both of which demand heightened olfactory ability.Confirmation requires histological analysis to determine the distribution of olfactory and respiratory epithelia and flow visualization to assess its functional implications.