What is Loricifera?
{{Taxobox | name = Loricifera | image = Pliciloricus_enigmatus.jpg | image_width = 200px | image_caption = ''Pliciloricus enigmatus'' | regnum = [[Animal]]ia | unranked phylum = [[Cycloneuralia]] | phylum = '''Loricifera''' | ordo = '''Nanaloricida''' | phylum_authority = [[Reinhardt Kristensen|Kristensen]], 1983 | subdivision_ranks = Genera | subdivision = }} '''Loricifera''' <ref>from [[Latin]], ''lorica'', [[corset]] + ''ferre'', to bear</ref> is a recently discovered [[ecdysozoa]]n [[phylum]] of [[Ocean|marine]] animals. The phylum includes the first animals known to exist in a completely [[anoxic]] environment (no oxygen at all).<ref name=Nature/> The phylum was described in 1983 by Reinhardt Kristensen.<ref name=Heiner>Heiner I. & Kristensen R.H. 2005. Two new species of the genus ''Pliciloricus'' (Loricifera, Pliciloricidae) from the Faroe Bank, North Atlantic. ''Zoologischer Anzeiger''. '''243''': 121–138.</ref> They are a [[phylum]] of very small animals which live in [[sediment]]. There are now twenty-two described [[species]], in eight [[genera]].<ref name=anzieger>Gad G. 2005. Successive reduction of the last instar larva of Loricifera, as evidenced by two new species of ''Pliciloricus'' from the Great Meteor Seamount (Atlantic Ocean). ''Zoologischer Anzeiger''. '''243''': 239–271.</ref><ref name=Ruppert>Ruppert, Edward E., Richard S. Fox, and Robert D. Barnes. 2004. ''Invertebrate zoology''. 7th ed. Toronto: Brooks/Cole—Thomson. p776.</ref> In addition, there are about 100 more species which have been collected, but not yet described.<ref name=anzieger/> Their size ranges from 100&nbsp;µm to about 1&nbsp;mm.<ref name=Heiner2005>Heiner I. 2005. Preliminary account of the loriciferan fauna of the Faroe Bank (NE Atlantic). ''Biofar Proceedings'' 2005: 213–219.</ref> Their habitat is in the spaces between marine [[Particle size (grain size)|gravel]] to which they attach themselves. They are among the most recently discovered groups of [[Metazoan]]s.<ref name=dane>Kristensen, R.M. 2002. An introductio