The Acanthocephala (Greek "akanthos", thorn + "kephale", head) are a group of parasitic worms. They may be called known as "acanthocephales", "thorny-headed worms", or "spiny-headed worms". They have an evertable proboscis, armed with spines, which they use to pierce and hold the gut wall of the host. Acanthocephalans have no gut and absorb nutrients directly from the host’s gut. 