Lophotrochozoa
From Wikipedia, the free encyclopedia
 |
This article does not cite any references or sources. (January 2008) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
| Lophotrochozoa Fossil range: Early Cambrian - Recent |
||||||||
|---|---|---|---|---|---|---|---|---|
 Caribbean Reef Squid or Sepioteuthis sepioidea is a complex lophotrochozoan.
|
||||||||
| Scientific classification | ||||||||
|
||||||||
| Phyla | ||||||||
The Lophotrochozoa (pronounced /ləˌfɒtroʊkəˈzoʊə/, "crest-bearing animals") are one of two major groupings of protostome animals. The taxon was introduced in the 1995 in a paper by 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]
Trochozoans produce trochophore larvae, which have two bands of cilia around their middle. 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 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 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.
Other phyla are included on the basis of molecular data.
|
[edit] References
[edit] External links
 |
This animal-related article is a stub. You can help Wikipedia by expanding it. |
