The term superior frontal sulcus refers to a groove that parallels the longitudinal fissure on the dorsal surface of the frontal lobe. Separating the superior frontal gyrus from the middle frontal gyrus, it exists only in the human. Some authors use the term 'sulcus frontalis superior' in reference to the posterior supraprincipal dimple of the macaque. They do not, however, regard that to be a homologous structure; the macaque does not have a superior frontal sulcus ( Bonin-1947 ). The superior frontal sulcus and the superior precentral sulcus of the human correspond to the superior limb of the arcuate sulcus of the macaque ( Matelli-2004 ). And equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).