A tooth crown morphology framework for interpreting the diversity of primate dentitions

Abstract

Variation in tooth crown morphology plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. While a growing number of studies have identified developmental mechanisms linked to tooth size and cusp patterning in mammalian crown morphology, it is unclear (1) to what degree these are applicable across primates and (2) which additional developmental mechanisms should be recognized as playing important roles in odontogenesis. From detailed observations of lower molar enamel–dentine junction morphology from taxa representing the major primate clades, we outline multiple phylogenetic and developmental components responsible for crown patterning, and formulate a tooth crown morphology framework for the holistic interpretation of primate crown morphology. We suggest that adopting this framework is crucial for the characterization of tooth morphology in studies of dental development, discrete trait analysis, and systematics.

Evaluating predictions of the patterning cascade model of crown morphogenesis in the human lower mixed and permanent dentition

“…For example, identifying characters prone to homoplasy can help us to improve phylogenetic methods (167). Although outside the scope of the current study, we hope researchers can leverage current findings to approach specific questions surrounding macroevolution of crown form in the hominoid fossil record or microevolutionary changes characterizing contemporary populations [ 170 – 173 ].…”