2019-2020 Faculty Research Grants

James Hayward (Biology)

Developmental Histology of Gull and Dinosaur Bones

Andrews University houses what is likely the most complete developmental series of skeletons for any wild bird. Seventy-five skeletons of known-aged Glaucous-winged Gull chicks and 13 skeletons of adult gulls were collected during the 1980s and 1990s for a study of age-related processes in these birds. A modest sample of femora and humeri was prepared from these skeletons as transverse and longitudinal thin sections. Histological analysis showed that juvenile gull bones exhibit unusual fine-structural features. Specifically, transverse sections of the bones exhibit isotropy (random orientations of collagen fibers), whereas in longitudinal sections the bones exhibit anisotropy (parallel orientation of collagen fibers with the long dimension of the bone). This was a surprising discovery because parallel-fibered bone typically is associated with slow bone growth, not a characteristic of juvenile gull bones. Intriguingly, a similar pattern has been observed for Tyrannosaurus rex bones studied at Oklahoma State University. As a result, I have been invited collaborate on a comparative study of gull and dinosaur bones at OSU. Based on the results of the preliminary study, I predict the discovery of widespread similarities between microstructural features of gull and T. rex bones. These similarities between a living bird and an extinct dinosaur will allow us to infer important features of dinosaur physiology, behavior, and ecology