Hellenica World

Lophotrochozoa

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Spiralia
Cladus: Lophotrochozoa
Phyla: Annelida - Brachiopoda - Bryozoa - Echiura - Entoprocta - †Hyolitha - Mollusca - Nemertea - Phoronida - Sipuncula

References

* Bleidorn, C. 2008: Lophotrochozoan relationships and parasites. A snap-shot. Parasite, 15: 329-332.
* Helmkampf, M.; Bruchhaus, I.; Hausdorf, B. 2008: Multigene analysis of lophophorate and chaetognath phylogenetic relationships. Molecular phylogenetics and evolution, 46: 206-214.
* Passamaneck, Y.; Halanych, K.M. 2006: Lophotrochozoan phylogeny assessed with LSU and SSU data: evidence of lophophorate polyphyly. Molecular phylogenetics and evolution, 40: 20–28.
* Wanninger, A. 2008: Comparative lophotrochozoan neurogenesis and larval neuroanatomy: recent advances from previously neglected taxa. Acta biologica hungarica, 59(suppl. S): 127-136.
* Yokobori, S.-i.; Iseto, T.; Asakawa, S.; Sasaki, T.; Shimizu, N.; Yamagishi, A.; Oshima, T.; Hirose, E. 2008: Complete nucleotide sequences of mitochondrial genomes of two solitary entoprocts, Loxocorone allax and Loxosomella aloxiata: implications for lophotrochozoan phylogeny. Molecular phylogenetics & evolution, 47: 612-628.

Vernacular names
Internationalization
English: lophotrochozoans
Français: Lophotrochozoaires
Italiano: Lofotrocozoi
日本語: 冠輪動物上門

The Lophotrochozoa (pronounced /ləˌfɒtrɵkɵˈzoʊ.ə/, "crest/wheel animals") are a major grouping of protostome animals. The taxon was introduced in 1995 in a paper by Kenneth M Halanych et al. based on molecular data. 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.[1]

Terminology

The word "lophotrochozoan" is sometimes equated with spiralian.[2] When used in a broader sense (sensu lato), it can include rotifers and platyhelminthes.[3] When used sensu stricto, it refers to a subgroup of Spiralia.
Groups

The Lophotrochozoa comprise two groups, the trochozoans and the lophophorata. The exact relationships between the different phyla are not entirely certain. However, it appears that neither the lophophorates nor the trochozoa are monophyletic groups by themselves, but are mixed together.[4]

* Trochozoans produce trochophore larvae, which have two bands of cilia around their middle.[4] 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, Echiura, Pogonophora and Annelida.[4]

* 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, before RNA trees placed them together with the trochozoans. The Lophophorata include the Bryozoa, Entoprocta, Phoronida, and Brachiopoda.[4]

Other phyla are included on the basis of molecular data.


A phylogenetic tree of the Lophotrochozoa as suggested by Dunn et al. (2008)

References

1. ^ Philippe, Hervé, Nicolas Lartillot1 and Henner Brinkmann. (2005) "Multigene Analyses of Bilaterian Animals Corroborate the Monophyly of Ecdysozoa, Lophotrochozoa, and Protostomia." Molecular Biology and Evolution 2005 22(5):1246-1253; doi:10.1093/molbev/msi111.
2. ^ 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 2614230. PMID 18192183. http://rstb.royalsocietypublishing.org/cgi/pmidlookup?view=long&pmid=18192183.
3. ^ "Explanations.html". http://science.kennesaw.edu/~jdirnber/InvertZoo/Tree/Explanations.html. Retrieved 2009-06-28.
4. ^ a b c d Introduction to the Lophotrochozoa - accessed 8 August 2008

Further reading

* Podsiadlowski R. 2009. Phylogeny and mitochondrial gene order variation in Lophotrochozoa in the light of new mitogenomic data from Nemertea. BMC Genomics 2009, 10:364. doi:10.1186/1471-2164-10-364

Images

Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License

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