Platytrochozoa

Platytrochozoa
Garden snail ( Cornu aspersum ) a basal playtrochozoan
Barentsia laxa colony (Entoprocta)
Scientific classification
Kingdom:	Animalia
Subkingdom:	Eumetazoa
Clade:	ParaHoxozoa
Clade:	Bilateria
Clade:	Nephrozoa
Clade:	Protostomia
Clade:	Spiralia
Clade:	Platytrochozoa Struck et al. 2014
Clade
Rouphozoa Lophotrochozoa Mesozoa?

The Platytrochozoa are a proposed basal clade of spiralian animals as the sister group of the Gnathifera. The Platytrochozoa were divided into the Rouphozoa and the Lophotrochozoa. ^[1] A more recent study suggests that the mesozoans also belong to this group of animals, as sister of the Rouphozoa. ^[2]

Spiralia	Gnathifera Platytrochozoa Rouphozoa Gastrotricha Platyhelminthes Mesozoa Lophotrochozoa

An alternative phylogeny was given in 2019, with a basal grouping of Mollusca and Entoprocta named Tetraneuralia, and a second grouping of Nemertea and Platyhelminthes named Parenchymia as sister of Annelida. In this proposal, Lophotrochozoa would become roughly synonymous with Platytrochozoa, and Rouphozoa would be unsupported. ^[3]

Protostomia	Ecdysozoa   Spiralia   (s.l.)  / Gnathifera   Lophotrochozoa  /    Tetraneuralia     Mollusca Entoprocta     Gastrotricha   Lophophorata       Ectoprocta Phoronida Brachiopoda Annelida   Parenchymia     Platyhelminthes Nemertea   Platytrochozoa  /  Spiralia   (s.s.)   Gnathospiralia

In the 2022 study the Platytrochozoa clade is not recovered at all; spiralians (in this case identical with the Lophotrochozoa according to its definition) are divided into "Platyzoa s.l." (traditional Platyzoa expanded to include Bryozoa and Mesozoa) and Trochozoa clades: ^[4]

Spiralia/	Platyzoa  s.l. Bryozoa/Ectoprocta Entoprocta Cycliophora Gastrotricha Gnathifera Platyhelminthes Mesozoa Trochozoa Annelida Brachiozoa Nemertea Mollusca
Lophotrochozoa

References

1. Struck, Torsten H.; Wey-Fabrizius, Alexandra R.; Golombek, Anja; Hering, Lars; Weigert, Anne; Bleidorn, Christoph; Klebow, Sabrina; Iakovenko, Nataliia; Hausdorf, Bernhard (2014-07-01). "Platyzoan Paraphyly Based on Phylogenomic Data Supports a Noncoelomate Ancestry of Spiralia". Molecular Biology and Evolution. 31 (7): 1833–1849. doi: 10.1093/molbev/msu143 . PMID   24748651.
2. Lu, Tsai-Ming; Kanda, Miyuki; Satoh, Noriyuki; Furuya, Hidetaka (2017). "The phylogenetic position of dicyemid mesozoans offers insights into spiralian evolution". Zoological Letters. 3 (1): 6. doi: 10.1186/s40851-017-0068-5 . PMC   5447306 . PMID   28560048.
3. Marlétaz, Ferdinand; Peijnenburg, Katja T.C.A.; Goto, Taichiro; Satoh, Noriyuki; Rokhsar, Daniel S. (2019). "A New Spiralian Phylogeny Places the Enigmatic Arrow Worms among Gnathiferans". Current Biology. 29 (2): 312–318.e3. doi: 10.1016/j.cub.2018.11.042 . ISSN   0960-9822. PMID   30639106.
4. Drábková, Marie; Kocot, Kevin M.; Halanych, Kenneth M.; Oakley, Todd H.; Moroz, Leonid L.; Cannon, Johanna T.; Kuris, Armand; Garcia-Vedrenne, Ana Elisa; Pankey, M. Sabrina; Ellis, Emily A.; Varney, Rebecca; Štefka, Jan; Zrzavý, Jan (13 July 2022). "Different phylogenomic methods support monophyly of enigmatic 'Mesozoa' (Dicyemida + Orthonectida, Lophotrochozoa)". Proceedings of the Royal Society B: Biological Sciences. 289 (1978: 20220683). doi:10.1098/rspb.2022.0683. ISSN   1471-2954. PMC   9257288 . PMID   35858055.