Castellanization of the term Cephalspis . It means head armored or protected by a scab or shell. Protected with armor. It was the genus of fossil fish they were also called Ostracodermos.
Cefalaspis : Genus of placoderm fish of the family of cephalospids whose species are endowed with a cephalic shield, depressed, in the form of a crescent, prolonged towards the back of the body by two long lateral tips.