Dental microwear profilometry of African non-cercopithecoid catarrhines of the Early Miocene
The early Miocene of Kenya, roughly 23-16 million years ago, has yielded the remains of many important fossil species that provide a glimpse of the higher primate radiation at a time of major faunal turnover in Africa. These taxa, commonly called the Miocene apes, have been subject to innumerable studies, yet there is still no consensus on their diets, which is a major component in reconstructing their environmental niches. In this study, I analyzed the dental microwear textures of fossil primates from the Early Miocene of Kenya. I collected high-resolution casts of all molar specimens at the National Museums of Kenya, Nairobi, and inspected them with scanning confocal profilometry, a method that distinguishes between patterns in enamel damage caused by mastication of different types of food. This revealed 83 individuals with microwear of the fossil genera Dendropithecus, Micropithecus, Limnopithecus, Proconsul, Kalepithecus, Nyanzapithecus, and Rangwapithecus. Scale-sensitive fractal analysis was used to generate texture attributes, which aims to quantify enamel damage patterns for each specimen, and the fossil taxa were compared to each other and to living primate groups. My analyses revealed no significant variation in microwear texture among the fossil taxa, which suggests the fossil taxa consumed foods with similar mechanical properties despite striking morphological differences. However, further analysis separates the Miocene fossil sample from several living primate genera, which suggests that the primates of the African Early Miocene had generalized diets and had not yet specialized to the degree of many modern taxa, despite variation in size and tooth form.