Tooth crown tissue proportions and enamel thickness in Early Pleistocene Homo antecessor molars (Atapuerca, Spain)

A groundbreaking analysis of Homo antecessor molars from the Early Pleistocene Gran Dolina-TD6 site (Atapuerca, Spain) reveals that while these teeth exhibit thick enamel typical of most hominins, their dentine distribution and enamel thickness patterns more closely resemble those of Neanderthals than other fossil or modern humans. This suggests an early emergence of Neanderthal-like dental traits in this species, predating the Middle Pleistocene by over 800,000 years. Researchers used high-resolution imaging to characterize the inner structural organization of 17 H. antecessor molars, comparing them with a vast comparative sample (n=355) from African, Asian, and European hominin populations. The findings indicate that while total crown dentine percentages align with modern humans, lateral crown dentine proportions are higher, mirroring the Neanderthal signal. Enamel distribution maps further support this similarity, with thicker enamel spread more peripherally in H. antecessor molars, unlike other hominins and modern humans where cuspal enamel tends to be thicker.

Martín-Francés, L., Martinón-Torres, M., Martínez de Pinillos, M., García-Campos, C., Modesto-Mata, M., Zanolli, C., Rodríguez, L., & Bermúdez de Castro, J. M. (2018). Tooth crown tissue proportions and enamel thickness in Early Pleistocene Homo antecessor molars (Atapuerca, Spain). Plos One, 13(10), e0203334. https://doi.org/10.1371/journal.pone.0203334