89.6 Friday, Jan. 6 Strut Your Stuff: Frontal Sinus Complexity in Bovidae and Carnivora CURTIS, Abigail A.*; FARKE, Andrew A.; Univ. of California, Los Angeles; Raymond M. Alf Museum of Paleontology firstname.lastname@example.org
Paranasal sinuses, cavities found in the skulls of many mammal species, form when nasal epithelium pneumatizes surrounding bones. Of the paranasal sinuses, the frontal sinuses are the most variable, and were acquired and lost multiple times within Mammalia. Here we investigate frontal sinus complexity in bovids and carnivores, two clades that independently evolved frontal sinuses exhibiting great morphological disparity. The frontal sinuses range from puny to expansive, and from relatively simple, un-strutted sinuses, to highly complex sinuses with extensive struts. We addressedtwo questions in this study: 1) does sinus complexity increase with sinus size?; and 2) does the presence of supra-cranial structures affect sinus complexity? We sampled multiple individuals of 45 species of bovids and 24 species of carnivores and representing the morphological and taxonomic diversity within each clade. Sinus surface area and volume, proxies for sinus size and complexity, were reconstructed from CT (computed tomography) scans of each specimen. Sinus surface area and volume are strongly correlated and scale with positive allometry in both bovids and carnivores, suggesting that sinus complexity increases at a greater rate than sinus volume. Bovids have a higher scaling coefficient than carnivores, suggesting that supracranial structures may increase sinus complexity.