Macrostomorpha
{{Short description|Clade of flatworms}}
{{Automatic taxobox
| image = Macrostomum lignano.jpg
| image_caption = Macrostomum lignano
| taxon = Macrostomorpha
| authority = Doe, 1986
| subdivision_ranks = Subordinate taxa
| subdivision =
- Family Haplopharyngidae
- Family Macrostomidae
- Clade Dolichomicrostomida
- Genus Bradynectes
- Genus Myozona
}}
Macrostomorpha is a clade of free living flatworms in the group Rhabditophora.
Description
Species of Macrostomorpha are characterized by having the necks of the viscid gland and releasing gland emerging in a common collar of anchor cell microvilli. They also gave aciliary speratozoa and a pharynx of the simplex coronatus type.{{cite journal | doi = 10.1007/BF00312205| title = Ultrastructure of the copulatory organ of Haplopharynx quadristimulus and its phylogenetic significance (Plathelminthes, Haplopharyngida)| date = 1986| last1 = Doe| first1 = David A.| journal = Zoomorphology| volume = 106| issue = 3| pages = 163–173}} Macrostomorpha constitute a basal group in Rhabditophora, showing such plesiomorphic condition as entolecithal eggs and spiral cleavage.{{cite journal | last1 = Egger| first1 = Bernhard | year = 2015 | title = A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms | url= | journal = Current Biology | volume = 25 | issue = 10| pages = 1347–1353 | doi=10.1016/j.cub.2015.03.034|display-authors=etal | pmid=25866392 | pmc=4446793| bibcode = 2015CBio...25.1347E }} Another trait found among members of the clade is the presence of hard stylet in the male copulatory organ.
Phylogeny and systematics
Originally the clade Macrostomorpha was divided into two groups: Haplopharyngida (containing a single family, Haplopharyngidae) and Macrostomida (containing the families Macrostomidae, Microstomidae and Dolichomacrostomidae). However, molecular studies revealed that these groups are not monophyletic. The current phylogenetic classification is presented in the following tree:{{cite journal | doi = 10.1016/j.ympev.2015.06.004| title = The first multi-gene phylogeny of the Macrostomorpha sheds light on the evolution of sexual and asexual reproduction in basal Platyhelminthes| date = 2015| last1 = Janssen| first1 = Toon| last2 = Vizoso| first2 = Dita B.| last3 = Schulte| first3 = Gregor| last4 = Littlewood| first4 = D. Timothy J.| last5 = Waeschenbach| first5 = Andrea| last6 = Schärer| first6 = Lukas| journal = Molecular Phylogenetics and Evolution| volume = 92| pages = 82–107| pmid = 26093054| bibcode = 2015MolPE..92...82J}}
{{clade| style=font-size:100%;line-height:80%
|label1=Macrostomorpha
|1={{Clade
|2={{Clade
|2={{Clade
|1=Myozona
|2={{Clade
|1=Bradynectes
|label2=Dolichomicrostomida
|2={{Clade
}}
}}
}}
}}
}}
}}