Occipital bun
An occipital bun, also called an occipital spur, occipital knob, chignon hook or inion hook, is a prominent bulge or projection of the occipital bone at the back of the skull. It is important in scientific descriptions of classic Neanderthal crania. It is found among archaic Homo species (including Neanderthals), as well as Upper Pleistocene Homo sapiens and present-day human populations.