| Neodermata | |
|---|---|
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| Fasciola hepatica, a neodermatan | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Platyhelminthes |
| Subphylum: | Rhabditophora |
| Superclass: | Neodermata Ehlers, 1985[1] |
| Orders | |
Neodermata is a clade ofrhabditophoranflatworms containing the parasitic groupsTrematoda,Monogenea andCestoda.
All neodermatans areparasites, in many groups having a free-swimminglarval stage. The most striking feature uniting all neodermatans is that the ciliatedepidermis (typical of most flatworms) is cast off in adult worms, being replaced by asyncytium calledtegument orneodermis. Other characters found in all neodermatans are related to the anatomy of theprotonephridium and the rootlets of epidermal locomotorycilia.[2]
Currently, the monophyly of Neodermata is undisputed, being supported by both morphological and molecular data.[3] It is clear that they evolved from free-living flatworms (turbellarians), but their sister-group was for a long time a matter of debate. The first attempts to reconstruct the phylogeny of flatworms, based on morphological evidence, consideredRhabdocoela to be the sister-group of Neodermata, but this was based on weak morphological similarities and was not supported by molecular studies.[4]
The most recent evidences put the orderBothrioplanida as the sister-group of Neodermata, uniting them in a clade calledBothrioneodermata.[4]