Occipital spurs, also called as occipital knob, occipital bun, chignon or inion hook, is an exaggerated external occipital protuberance (EOP). It is frequently discussed in anthropological literature as a Neanderthal trait but hardly reported and considered as a normal variant in medical literature. It is a frequent finding among males and hence a prominent occipital spur is often used in gender determination in forensic investigations.1 EOP can be of three different types: type I, smooth; type II, crest form; type III, spine form.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753744/
https://en.wikipedia.org/wiki/Occipital_bun
https://en.wiktionary.org/wiki/occipital_bun
