Editing Gnathostomulid (section)

==Taxonomy==
{{See also|List of bilaterial animal orders}}
There are approximately 100 described species<ref name=Zhang2011>{{cite journal| author=Zhang, Z.-Q.| title=Animal biodiversity: An introduction to higher-level classification and taxonomic richness | journal=Zootaxa| volume=3148| year=2011| pages=7–12| url=http://mapress.com/zootaxa/2011/f/zt03148p012.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://mapress.com/zootaxa/2011/f/zt03148p012.pdf |archive-date=2022-10-09 |url-status=live| doi=10.11646/zootaxa.3148.1.3 }}</ref> and certainly many more as yet undescribed. The known species are grouped in two orders. The [[Filospermoidea|filospermoids]] are very long and are characterized by an elongate rostrum. The [[Bursovaginoidea|bursovaginoids]] have paired sensory organs and are characterized by the presence of a penis and a sperm-storage organ called a bursa.<ref name= Barnes/>

Gnathostomulids have no known fossil record, though there are (debatable) similarities between the jaws of modern gnathostomulids and certain conodont elements. (Ochietti & Cailleux, 1969; Durden et al, 1969)<ref>Cited in chapter 2, p192 of Andreas Schmidt-Rhaesa'a 2015 Gastrotricha and Gnathifera, VOl 3 of Gast---, Cycloneuralia and Gnath---.</ref>

They appear to be a sister clade to the [[Syndermata]].<ref name=IZ/><ref>{{cite journal|last2=Tobergte|first2=S.|last3=Struck|first3=T.H.|date=May 2015|title=Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes)|journal=Mol Phylogenet Evol|volume=86|pages=49–63|doi=10.1016/j.ympev.2015.02.013|pmid=25796325|last1=Golombek|first1=A.}}<!--|access-date=30 May 2016--></ref>