The Coronal Suture as an Indicator of the Caudal Border of the Macaque Monkey Prefrontal Cortex

In order to estimate the extent of cortical subdivisions in the now extinct Neanderthals, we explored the relationship between skull and brain morphology in extant primate species, including humans. In this study, we used macaque monkeys (Macaca fascicularis) to determine the relationship between the location of sutures and the location of major sulci of the brain. Among the sulci examined, the inferior limb of the arcuate sulcus showed a close spatial relationship with the ventral portion of the coronal suture. The inferior limb of the arcuate sulcus is homologous to the ventral part of the precentral sulcus in modern humans, and it defines the caudal border of the prefrontal association cortex. These findings prompted us to examine whether a similar relationship could be observed in Neanderthals and modern humans, in order to obtain a more accurate inference of the extent of prefrontal cortical development in Neanderthals.