Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.
College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.
Am J Biol Anthropol. 2024 Dec;185(4):e25031. doi: 10.1002/ajpa.25031. Epub 2024 Sep 20.
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.
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.
The molar macrowear patterns of P. abelii and P. pygmaeus show no significant differences in most of the variables examined in this study. 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. However, we do observe a more variable wear in P. pygmaeus.
Similarities in molar macrowear patterns between the two species could be linked to overlapping long-term diets, primarily composed of ripe and pulpy fruits. Dental macrowear is a cumulative process that occurs during the individual's lifetime, and it may be difficult to detect seasonal changes through its examination. Future studies could integrate tooth micro- and macrowear data for a better understanding of primate dental ecology.
猩猩分布于婆罗洲（红毛猩猩）和苏门答腊（苏门答腊猩猩和塔潘矮猩猩）的热带雨林中，主要被认为是食果动物。然而，生态研究报告称这些物种的进食行为存在差异。与苏门答腊猩猩相比，红毛猩猩花更多的时间进食低质量的食物，如树皮和坚韧的植被。本研究旨在探讨这两个物种的臼齿宏观磨耗模式是否存在地理变异。
我们分析了 58 只猩猩标本的第二下颌臼齿的宏观磨耗模式，将牙齿地形测量（咬合缓解指数、牙本质暴露百分比和釉质磨损百分比）与咬合指纹分析方法相结合。
在所研究的变量中，苏门答腊猩猩和红毛猩猩的臼齿宏观磨耗模式没有显著差异。虽然红毛猩猩的臼齿通常具有更平坦的咬合形态，其压碎和研磨区域略大于苏门答腊猩猩，但这些差异没有统计学意义。然而，我们确实观察到红毛猩猩的磨损更具可变性。
两种物种之间相似的臼齿宏观磨耗模式可能与重叠的长期饮食有关，主要由成熟和多汁的水果组成。牙齿宏观磨耗是一个在个体一生中发生的累积过程，通过其检查可能难以检测到季节性变化。未来的研究可以整合牙齿微观和宏观磨耗数据，以更好地了解灵长类动物的牙齿生态。
