Marian University College of Osteopathic Medicine (MU-COM) assistant professor of anatomy Dr. David Dufeau’s research on middle ear sinus system development in the American alligator has been published by the international peer-reviewed journal PLoS ONE.
The paper describes the latest efforts by Dufeau, a comparative anatomist and evolutionary biologist, to better understand why alligators have extensive ear-sinus space – he describes the animals as “fantastic air-heads” – compared to humans and other animals and how all that sinus cavity space affects the alligators’ hearing.
“Like many scientists, my research ideas start with an observation of something that strikes me as unusual,” Dufeau explained. “Something along the lines of ‘Huh, that’s odd; what’s up with that?’ And alligator middle-ear sinuses are indeed odd.”
The paper’s findings are intended to contribute to laying a foundation for examining the sinus similarities among modern birds and crocodiles as well as similar extinct reptiles, such as dinosaurs, and birds, Dufeau explained.
“In Dr. Dufeau’s newly published work he has opened a window on general considerations about sound conduction [through] a study of a non-human species [in which] an important hearing-related property is exaggerated,” said Dr. Bryan Larsen, MU-COM dean of research. “[This helps] to develop more understanding of the normal and abnormal human hearing. [These are] conditions that concern medicine as well as biology.”
For his research, Dufeau utilized CT (computed tomography) scanning to allow three-dimensional visualization of the relationship among bone, soft-tissue and space in 13 alligator skulls displaying a dramatic range of head size.
Dufeau came to Marian University in 2013 from the University of Missouri School of Medicine. In addition to pursuing his research interests, he has taught anatomy at the medical school level for nearly a decade.
His research and teaching interests collide in his 3-D Visualization Lab at MU-COM where he trains medical students in the interpretation of diagnostic sectional images such as those produced through CT, MRI (magnetic resonance imaging) and other similar technologies.
“This experience gives the students the opportunity to practice expert level anatomy and learn how to reassemble a sequence of images representing slices through the body into three-dimensional anatomy,” Dufeau explained.
Dufeau’s lab students routinely produce models and reconstructions that he is then able to use in his lectures or print out on MU-COM’s 3-D printer for use in future lab tutorials.
“Understanding how other vertebrate animals are organized anatomically, and how these anatomical parts function in these different animals, is a great asset for explaining human anatomy and function,” Dufeau said of his research. “Humans are very specialized animals in some ways and very ordinary in others.”
Dr. Lawrence M. Witmer at Ohio University’s Heritage College of Osteopathic Medicine collaborated on the study and co-authored the paper.
Read the paper: “Ontogeny of the Middle-Ear Air-Sinus System in Alligator mississippiensis (Archosauria: Crocodylia)"
Accompanying content: 3-D labeled model of the middle-ear sinus system of an alligator hatchling skull used in the study
Data from the paper: Files, images, etc.