marginal sulcus marginal sulcus in neuroanatomy, the marginal sulcus (margin of the cingulate sulcus) is a sulcus (crevice) that may be considered the termination of the cingulate sulcus. it separates the paracentral lobule anteriorly and the precuneus posteriorly. marginal sulcusmedial surface of left cerebral hemisphere. (marginal sulcus shown in red.)detailsidentifierslatinramus marginalis, sulcus marginalisneuronames98neurolex idbirnlex_4030ta98a14.1.09.204ta25478fma83773anatomical terms of neuroanatomy additional images position of marginal sulcus (shown in red). transverse sections of brains of vervet monkey. it showing difference of the relative position of the left and right ascending ramus of the cingulate sulcus.