Frontal sinus variation in extant species of the genera Pan, Gorilla

Frontal pneumatisation is not present in all primates, and among extant species, ethmoidally-derived frontal sinuses are only the genera Pan, Gorilla Homo. A simple repeatable method described here to quantify variation shape, size bilateral of sinuses. This has allowed first large study these variables, including analyses samples P. paniscus, troglodytes, G. gorilla several geographically diverse populations H. sapiens. sinus shape potential phylogenetic markers primate systematics. We suggest that, contrast an allometric relationship between endocranial form Pan Gorilla, sapiens autapomorphic having highly variable, supero-inferiorly sinuses, whose unrestricted by cranial form. However, we also describe differences those taxa. differs from other taxa relatively smaller that more variable size. In paniscus gorilla, correlates positively with overall braincase. suggests space available bone structures non-human primates analysed allows develop under slight constraint (if any) surrounding structures. sapiens, a significant correlation observed asymmetry anterior extension lobes brain vertical orientation bone, its reduced thickness, reduction supraorbital tori increased influence appear have modified integration skull, region our species compared nearest relatives. Our results reduce possibility strong functional origin for analysed.