Gnathostomulids, or jaw worms, are a small phylum of microscopic marine animals. They appear closely related to rotifers and their allies, together making up the Gnathifera. Gnathostomulids have no fossil record.
Gnathostomulida - an enigmatic metazoan phylum from both morphological and molecular perspectives.
Sørensen, M. An SEM study of the jaws of Haplognathia rosea and Rastrognathia macrostoma (Gnathostomulida), with a preliminary comparison with the rotiferan trophi.
Sørensen, M. Phylogeny and jaw evolution in Gnathostomulida, with a cladistic analysis of the genera.