| Macrostomorpha | |
|---|---|
| |
| Macrostomum lignano | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Platyhelminthes |
| Subphylum: | Rhabditophora |
| Subclass: | Macrostomorpha Doe, 1986 |
| Subordinate taxa | |
| |
Macrostomorpha is a clade of free living flatworms ranked either as class or subclass in the group Rhabditophora. There are about 260 described species in two orders - marine, freshwater and brackish Macrostomida, which group most of the species diversity, and exclusively marine Haplopharyngida with only three described species.[1] Macrostomorpha constitute a basal group in Rhabditophora, showing such plesiomorphic condition as entolecithal eggs and spiral cleavage.[2] Another trait found among members of the clade is presence of hard stylet in the male copulatory organ.
- ^ "World Register of Marine Species". 29 April 2016.
- ^ Egger, Bernhard; et al. (2015). "A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms". Current Biology. 25 (10): 1347–1353. doi:10.1016/j.cub.2015.03.034. PMC 4446793. PMID 25866392.