Polymorphida

Polymorphida are an order of thorny-headed worms (phylum Acanthocephala). The adults of these parasitic platyzoans feed mainly on fish and aquatic birds.

Polymorphida
Corynosoma wegeneri
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Acanthocephala
Class:	Palaeacanthocephala
Order:	Polymorphida Petrochenko, 1956

This order contains 5 families:^[1][2]

• Centrorhynchidae Van Cleave, 1916
• Isthomosacanthidae Smales, 2012
• Plagiorhynchidae Meyer, 1931
• Pyriprobosicidae
• Polymorphidae Meyer, 1931