A preliminary radiographic analysis of dental development in Virunga mountain gorillas (Gorilla beringei beringei) from Volcanoes National Park, Rwanda.

Student First Name: 
Alexandra
Student Last Name: 
Kralick
Student Picture: 
Alexandra Kralick tracking mountain gorillas in Rwanda
Project Picture: 
Alexandra Kralick photographing mountain gorilla teeth in Rwanda
Expected Year of Graduation: 
2014
Department/Major: 
Biological Anthropology
Student Team Members: 
NA
Mentor(s): 
Dr. Shannon McFarlin, Assistant Professor of Anthropology
Other Team Members: 
Halszka Glowacka, Michael R. Cranfield, Tara S. Stoinski, Antoine Mudakikwa, Timothy G. Bromage
Fun Fact About Yourself: 
As an undergraduate teaching assistant for Intro to Biology I wrote a primatology lab where students modeled primate socioecological principals by competing for candy and practiced primatological methods by observing each other!
Project Abstract: 

ALEXANDRA E. KRALICK1, HALSZKA GLOWACKA2, MICHAEL R. CRANFIELD3, TARA S. STOINSKI4, ANTOINE MUDAKIKWA5, TIMOTHY G. BROMAGE6, SHANNON C. MCFARLIN1, 7

1Department of Anthropology, The George Washington University, Washington, DC, USA.
2 Institute of Human Origins, Arizona State University, Tempe, AZ, USA.
3Mountain Gorilla Veterinary Project, University of California Davis, USA.
4Dian Fossey Gorilla Fund International and Zoo Atlanta, Atlanta, GA, USA.
5Rwanda Development Board - Tourism and Conservation, Kigali, Rwanda.
6Departments of Biomaterials & Biomimetics and Basic Science & Craniofacial Biology, New York University College of Dentistry, NY, USA.
7Center for the Advanced Study of Hominid Paleobiology, The George Washington University, Washington, DC, USA.

Investigations of dental development have figured prominently in attempts to reconstruct fossil hominid life histories . However, comparative data from extant wild great apes of known age remain scarce, particularly from species other than chimpanzees. We report initial results from the first radiographic examination of dental development in wild Virunga mountain gorillas (Gorilla beringei beringei), using a well-documented sample of skeletons recovered in Rwanda. Virunga mountain gorillas are the least frugivorous among great apes and, despite their large size, show earlier ages at weaning and first birth. Thus, they provide a unique opportunity to test relationships between dental development, socioecology, and life history among hominoids. We test the hypothesis that mountain gorillas are accelerated in dental development, as they are in other life history traits, compared to chimpanzees. We collected radiographs of mandibular dentitions using a Nomad Pro portable dental x ray, from 16 individuals of known sex and age (0.0-14.9 years). Molar crown and root calcification status was scored following an eight-stage system (Kuykendall, 1996; Demirjian et al. 1973). In only one case did crown calcification stage fall outside of the age range reported for captive chimpanzees (Kuykendall, 1996). Differences were more commonly observed in root formation, where calcification stages were reached at later ages in three mountain gorillas. While these results do not support our hypothesis, future studies will incorporate an expanded sample and more refined staging system. Associated individual records also provide opportunities to test links between dental development, life history and health status in this population.

Funding was provided by the GW George Gamow Undergraduate Research Fellowship to A.K., and by the Leakey Foundation, National Geographic Society, and NSF BCS 0852866 and 0964944 to the Mountain Gorilla Skeletal Project.