One of the spines, probably denticle derivatives, occurring singly or in pairs just behind the orbit on the cheek area in some fossil sharks. May have occurred only in males and may have served to hold the female during copulation, e.g. in the Jurassic genera Hybodus, Asteracanthus and Acrodus. [ http://www.briancoad.com/dictionary/complete%20dictionary.htm ]
This is just here as a test because I lose it