Scalidophora

Scalidophora
Scientific classification
Kingdom:	Animalia
clade:	Cycloneuralia
(unranked):	Scalidophora
Phyla
Kinorhyncha Loricifera Priapulida possible stem groups: Palaeoscolecida[1] Archaeopriapulida
Synonyms
Cephalorhyncha

Scalidophora is a group of marine pseudocoelomate invertebrates, consisting of the three phyla Kinorhyncha, Priapulida, and Loricifera.^[2] The members of the group share a number of characteristics, including introvert larvae and moulting of the cuticle (ecdysis). Their closest relatives are thought to be the Panarthropoda, Nematoda and Nematomorpha; they are thus placed in the group Ecdysozoa.

The two species in the genus Markuelia, known from fossilized embryos from the middle Cambrian, are thought to be stem Scalidophorans.

The group has also been considered a single group, Cephalorhyncha,^[3] with three classes.

References

1. ^ Harvey, T.; Dong, X.; Donoghue, P. (2010). "Are palaeoscolecids ancestral ecdysozoans?". Evolution & development 12 (2): 177–200. doi:10.1111/j.1525-142X.2010.00403.x. PMID 20433458.  edit
2. ^ Telford MJ, Bourlat SJ, Economou A, Papillon D, Rota-Stabelli O (April 2008). "The evolution of the Ecdysozoa". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 363 (1496): 1529–37. doi:10.1098/rstb.2007.2243. PMC 2614232. PMID 18192181. http://rstb.royalsocietypublishing.org/cgi/pmidlookup?view=long&pmid=18192181. 
3. ^ "Explanations.html". http://science.kennesaw.edu/~jdirnber/InvertZoo/Tree/Explanations.html. Retrieved 2009-06-28.