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Temporal range: Early Cambrian - Recent
Caribbean reef squid.jpg
Caribbean reef squid or Sepioteuthis sepioidea is a complex lophotrochozoan.
Scientific classification e
Kingdom: Animalia
Subkingdom: Eumetazoa
Clade: Bilateria
Clade: Nephrozoa
(unranked): Protostomia
(unranked): Spiralia
Superphylum: Lophotrochozoa
Halanych et al., 1995

The Lophotrochozoa (/ləˌfɒtrkˈzə/, "crest/wheel animals") are a taxon of protostome animals. It includes Halwaxiida and Odontogriphus. The taxon was discovered based on molecular data.[1] Molecular evidence such as a result of studies of the evolution of small-subunit ribosomal RNA (rRNA) supports the monophyly of the phyla listed in the infobox shown at right.[2]


The word "lophotrochozoan" is sometimes equated with spiralian.[3] When used in a broader sense (sensu lato), it can include rotifers and platyhelminthes.[4] When used sensu stricto, it refers to a subgroup of Spiralia.


The Lophotrochozoa comprise two groups, the trochozoans and the lophophorata. The exact relationships between the different phyla are not entirely certain.

  • Trochozoans produce trochophore larvae, which have two bands of cilia around their middle.[5] Previously these were treated together as the Trochozoa, together with the arthropods, which do not produce trochophore larvae but were considered close relatives of the annelids because they are both segmented. However, they show a number of important differences, and the arthropods are now placed separately among the Ecdysozoa. The Trochozoa include the Nemertea, Mollusca, Sipuncula, and Annelida.[5]
  • The Lophophorata are united by the presence of a lophophore, a fan of ciliated tentacles surrounding the mouth, and so were treated together as the lophophorates. They are unusual in showing radial cleavage, and some authors considered them deuterostomes. The ‘clade’ Lophotrochozoa was founded on evidence from 18S ribosomal RNA,[1] but a later study on LSU and SSU ribosomal genes suggested that the Lophophorata is polyphyletic.[6]

Other phyla are included on the basis of molecular data.

With the introduction of Platytrochozoa and Rouphozoa, one candidate phylogeny is pictured below – though other studies recover a range of different alternative possibilities:[7][8][9][10]





















See also[edit]


  1. ^ a b Halanych, K.M., Bacheller, J., Liva, S., Aguinaldo, A. A., Hillis, D.M. and Lake, J.A. (17 March 1995). "18S rDNA evidence that the Lophophorates are Protostome Animals". Science. 267: 1641–1643. doi:10.1126/science.7886451. PMID 7886451. 
  2. ^ Hervé, Philippe; Lartillot, Nicolas; Brinkmann, Henner (May 2005). "Multigene Analyses of Bilaterian Animals Corroborate the Monophyly of Ecdysozoa, Lophotrochozoa, and Protostomia". Molecular Biology and Evolution. 22 (5): 1246–1253. doi:10.1093/molbev/msi111. PMID 15703236. 
  3. ^ Giribet G (April 2008). "Assembling the lophotrochozoan (=spiralian) tree of life". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 363 (1496): 1513–22. doi:10.1098/rstb.2007.2241. PMC 2614230Freely accessible. PMID 18192183. 
  4. ^ "Explanations.html". Retrieved 2009-06-28. 
  5. ^ a b "Introduction to the Lophotrochozoa". University of California, Berkeley. Retrieved 2016-09-05. 
  6. ^ Passamaneck, Y.; Halanych, K.M. (July 2006). "Lophotrochozoan phylogeny assessed with LSU and SSU data: evidence of lophophorate polyphyly". Mol Phylogenet Evol. 40 (1): 20–28. doi:10.1016/j.ympev.2006.02.001. PMID 16556507. 
  7. ^ Paps, Jordi; Baguñà, Jaume; Riutort, Marta (2009-10-01). "Bilaterian Phylogeny: A Broad Sampling of 13 Nuclear Genes Provides a New Lophotrochozoa Phylogeny and Supports a Paraphyletic Basal Acoelomorpha". Molecular Biology and Evolution. 26 (10): 2397–2406. doi:10.1093/molbev/msp150. ISSN 0737-4038. PMID 19602542. 
  8. ^ Struck, Torsten H.; Schult, Nancy; Kusen, Tiffany; Hickman, Emily; Bleidorn, Christoph; McHugh, Damhnait; Halanych, Kenneth M. (2007-01-01). "Annelid phylogeny and the status of Sipuncula and Echiura". BMC Evolutionary Biology. 7: 57. doi:10.1186/1471-2148-7-57. ISSN 1471-2148. PMC 1855331Freely accessible. PMID 17411434. 
  9. ^ Hausdorf, Bernhard; Helmkampf, Martin; Meyer, Achim; Witek, Alexander; Herlyn, Holger; Bruchhaus, Iris; Hankeln, Thomas; Struck, Torsten H.; Lieb, Bernhard (2007-12-01). "Spiralian Phylogenomics Supports the Resurrection of Bryozoa Comprising Ectoprocta and Entoprocta". Molecular Biology and Evolution. 24 (12): 2723–2729. doi:10.1093/molbev/msm214. ISSN 0737-4038. PMID 17921486. 
  10. ^ 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. ISSN 0737-4038. PMID 24748651. 

Further reading[edit]