Meeting Abstract

43.5  Wednesday, Jan. 5  Cats and Dogs in 3D: A Quantitative Study of Canid and Felid Frontal Sinuses using CT technology CURTIS, Abigail A.*; VAN VALKENBURGH, Blaire; Univ. of California, Los Angeles; Univ. of California, Los Angeles abigailacurtis@gmail.com

Located within the frontal bone, hollow cavities known as frontal sinuses are among the least studied components of the skull. Frontal sinuses are one of the four paranasal sinuses (maxillary, sphenoid, ethmoid, and frontal sinuses) that form as the nasal epithelium escapes the nasal capsule during development and invades surrounding bone. Various functions have been suggested for these structures such as lightening the skull or shock absorption but none is well accepted. Recent advances in imaging technologies, such as x-ray computed tomographic (CT) scanning have become available to researchers and allow nondestructive examination of intracranial structures such as sinuses. To better understand sinus morphology, we conducted a quantitative and comparative study of frontal sinuses in Felidae and Canidae using CT technology. We provide the first quantitative data on sinus size and three-dimensional shape within each clade using specialized imaging software and spherical harmonics (SPHARM). We examine relationships between sinus size and shape with body size, skull size, skull shape, prey size, and phylogeny. Frontal sinuses evolved independently in each lineage, offering the opportunity to compare differences in scaling between the two lineages. In both felids and canids, sinus size is correlated with body size and skull size. Results suggest that there is an overall size constraint on sinuses, suggesting a biomechanical and/or physiological role.