Our new study on the orangutan’s ecological diversity has been recently published in the American Journal of Biological Anthropology.
Orangutans are found in tropical rainforests of Borneo (Pongo pygmaeus) and Sumatra (Pongo abelii and Pongo tapanuliensis), and they are primarily considered frugivorous species. However, ecological studies reported differences in feeding behavior between these species. P. pygmaeus spend more time feeding on low quality foods, such as bark and tough vegetation than do P. abelii. The aim of this study is to investigate if there is any geographic variation in molar macrowear pattern between the two species.
tapanuliensis). Bornean orangutans are further divided into three subspecies: Pongo pygmaeus wurmbii (1), Pongo pygmaeus pygmaeus (2), and Pongo pygmaeus morio.
We analyzed the macrowear pattern of second mandibular molars of 58 orangutan specimens combining dental topographic measurements (occlusal relief index, percentage of dentine exposure, and percentage of enamel wear) with the occlusal fingerprint analysis method.
molar of Pongo pygmaeus showing the occlusal wear facets mapped
on the surface (on the right).
While P. pygmaeus molars are generally characterized by flatter occlusal morphology with slightly larger crushing and grinding areas than those of P. abelii, these differences are not statistically significant. Similarities in molar macrowear patterns between the two species could be linked to overlapping long-term diets, primarily composed of ripe and pulpy fruits.
