Palaeacanthocephala

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Spiralia
Cladus: Platyzoa
Phylum: Acanthocephala
Classis: Palaeacanthocephala
Ordines (3): Echinorhynchida - Heteramorphida - Polymorphida
[source: Catalogue of Life: 2011 Annual Checklist, plus (1) Heteramorphida]

References

Amin, O.M.; Van Ha, N. 2008: On a new acanthocephalan family and a new order, from birds in Vietnam. Journal of parasitology, 94: 1305-1310. doi: 10.1645/GE-1473.1
García-Varela, M.; Nadler, S.A. 2005: Phylogenetic relationships of Palaeacanthocephala (Acanthocephala) inferred from SSU and LSU rDNA gene sequences. Journal of parasitology, 91(6): 1401-1409. doi: 10.1645/GE-523R.1 JSTOR

links

Gibson, D. (2011). Palaeacanthocephala. In: Read, G.; Fauchald, K. (Ed) (2011). World Polychaeta database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=20285 on 2011-11-29

Palaeacanthocephala ("ancient thornheads") is a class within the phylum Acanthocephala. The adults of these parasitic platyzoans feed mainly on fish, aquatic birds and mammals.

The nuclei of the hypodermis (outer layer of skin) are fragmented and the males have two to seven cement glands, unlike their relatives the Archiacanthocephala which always have eight.