Age-related changes in molar topography and shearing crest length in a wild population of mountain Gorillas from Volcanoes National Park, Rwanda

Halszka Glowacka, Shannon C. McFarlin, Kierstin K. Catlett, Antoine Mudakikwa, Timothy Bromage, Michael R. Cranfield, Tara S. Stoinski, Gary T. Schwartz

Research output: Contribution to journalArticle

Abstract

Objectives Great ape teeth must remain functional over long lifespans. The molars of the most folivorous apes, the mountain gorillas, must maintain shearing function for 40+ years while the animals consume large quantities of mechanically challenging foods. While other folivorous primates experience dental senescence, which compromises their occlusal surfaces and affects their reproductive success as they age, it is unknown whether dental senescence also occurs in mountain gorillas. In this article, we quantified and evaluated how mountain gorilla molars change throughout their long lifespans. Materials and Methods We collected high-resolution replicas of M1s (n = 15), M2s (n = 13), and M3s (n = 11) from a cross-sectional sample of wild mountain gorilla skeletons from the Virunga Volcanoes, ranging in age from 4 to 43 years. We employed dental topographic analyses to track how aspects of occlusal slope, angularity, relief index, and orientation patch count rotated change with age. In addition, we measured the relative length of shearing crests in two- and three-dimensions. Results Occlusal topography was found to decrease, while 2D relative shearing crest length increased, and 3D relative crest lengths were maintained with age. Discussion Our findings indicate that shearing function is maintained throughout the long lifetimes of mountain gorillas. Unlike the dental senescence experienced by other folivorous primates, mountain gorillas do not appear to possess senesced molars despite their long lifetimes, mechanically challenging diets, and decreases in occlusal topography with age.

Original languageEnglish (US)
Pages (from-to)3-15
Number of pages13
JournalAmerican Journal of Physical Anthropology
Volume160
Issue number1
DOIs
StatePublished - May 1 2016

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Rwanda
Gorilla gorilla
national park
Tooth
geography
Population
life-span
Hominidae
Primates
compromise
Skeleton
animal
Recreational Parks
food
Diet
Food
experience

Keywords

  • aging
  • dental senescence
  • Gorilla beringei beringei
  • tooth wear

ASJC Scopus subject areas

  • Anthropology
  • Anatomy

Cite this

Age-related changes in molar topography and shearing crest length in a wild population of mountain Gorillas from Volcanoes National Park, Rwanda. / Glowacka, Halszka; McFarlin, Shannon C.; Catlett, Kierstin K.; Mudakikwa, Antoine; Bromage, Timothy; Cranfield, Michael R.; Stoinski, Tara S.; Schwartz, Gary T.

In: American Journal of Physical Anthropology, Vol. 160, No. 1, 01.05.2016, p. 3-15.

Research output: Contribution to journalArticle

Glowacka, Halszka ; McFarlin, Shannon C. ; Catlett, Kierstin K. ; Mudakikwa, Antoine ; Bromage, Timothy ; Cranfield, Michael R. ; Stoinski, Tara S. ; Schwartz, Gary T. / Age-related changes in molar topography and shearing crest length in a wild population of mountain Gorillas from Volcanoes National Park, Rwanda. In: American Journal of Physical Anthropology. 2016 ; Vol. 160, No. 1. pp. 3-15.
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