Protostomia (blastopore becomes the mouth; scizocoel)

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Gastrotricha
 Xenotrichula velox

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Cycliophora

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Gnathifera


Gnathifera - Gnathostomulida


Gnathifera - Micrognathozoa


Gnathifera - Acanthocephala



Gnathifera - Rotifera


Gnathifera - Seisonidea