Macrostomorpha

Macrostomorpha
	Macrostomum lignano
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Platyhelminthes
Subphylum:	Rhabditophora
Subclass:	Macrostomorpha; Doe, 1986
Subordinate taxa
	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.^[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.

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:^[3]

Macrostomorpha

Myozona

	Dolichomacrostomidae

	Microstomidae

References

^ Doe, David A. (1986). "Ultrastructure of the copulatory organ of Haplopharynx quadristimulus and its phylogenetic significance (Plathelminthes, Haplopharyngida)". Zoomorphology. 106 (3): 163–173. doi:10.1007/BF00312205.
^ Egger, Bernhard; et al. (2015). "A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms". Current Biology. 25 (10): 1347–1353. Bibcode:2015CBio...25.1347E. doi:10.1016/j.cub.2015.03.034. PMC 4446793. PMID 25866392.
^ Janssen, Toon; Vizoso, Dita B.; Schulte, Gregor; Littlewood, D. Timothy J.; Waeschenbach, Andrea; Schärer, Lukas (2015). "The first multi-gene phylogeny of the Macrostomorpha sheds light on the evolution of sexual and asexual reproduction in basal Platyhelminthes". Molecular Phylogenetics and Evolution. 92: 82–107. Bibcode:2015MolPE..92...82J. doi:10.1016/j.ympev.2015.06.004. PMID 26093054.

[Doe1986-1] Doe, David A. (1986). "Ultrastructure of the copulatory organ of Haplopharynx quadristimulus and its phylogenetic significance (Plathelminthes, Haplopharyngida)". Zoomorphology. 106 (3): 163–173. doi:10.1007/BF00312205.

[Egger-2] Egger, Bernhard; et al. (2015). "A Transcriptomic-Phylogenomic Analysis of the Evolutionary Relationships of Flatworms". Current Biology. 25 (10): 1347–1353. Bibcode:2015CBio...25.1347E. doi:10.1016/j.cub.2015.03.034. PMC 4446793. PMID 25866392.

[Janssen2015-3] Janssen, Toon; Vizoso, Dita B.; Schulte, Gregor; Littlewood, D. Timothy J.; Waeschenbach, Andrea; Schärer, Lukas (2015). "The first multi-gene phylogeny of the Macrostomorpha sheds light on the evolution of sexual and asexual reproduction in basal Platyhelminthes". Molecular Phylogenetics and Evolution. 92: 82–107. Bibcode:2015MolPE..92...82J. doi:10.1016/j.ympev.2015.06.004. PMID 26093054.

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