Acanthocephala is a phylum of parasitic worms known as acanthocephalansthorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host. Acanthocephalans have complex life cycles, involving at least two hosts, which may include invertebrates, fishes, amphibians, birds, and mammals.


  1. Archiacanthocephala
  2. Eoacanthocephala
  3. Palaeacanthocephala