The term calcarine fissure refers to a deep, internally complex fissure that opens onto the medial surface of the occipital lobe of the human ( Carpenter-1983 ) and the macaque ( Martin-2000 ). It separates the lingual gyrus (LNG) ventrally from the cuneus (CUN) and precuneus (PCU) dorsally. In some cases it extends rostrally as the anterior calcarine fissure fclfa) between the isthmus of the cingulate gyrus (ICGG) and the posterior parahippocampal gyrus (PHGp) as far as the hippocampal fissure (his). And in some cases it splits posteriorly into a dorsally curving superior calcarine fissure (clfs) and a ventrally curving inferior calcarine fissure (clfi) ( Duvernoy-1992; Martin-2000 ). Comparable structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ). Updated 11 Aug 2024.