(information as of 2009) NSF project 0118804 for research in the laboratories of Seth Tyler, Professor of Zoology, UMaine Matt Hooge, Postdoctoral Fellow, UMaine Wolfgang Sterrer, Bermuda Aquarium Christiane Todt, Postdoctoral Fellow, U. Vienna, UMaine Through support of the National Science Foundation in its PEET initiative (Partnerships for Enhancing Expertise in Taxonomy), we are engaged in research on the taxonomy of tiny, cryptic worms that many consider to be the most primitive of all bilaterally symmetrical animals (that is, all animals excluding the cnidarians and sponges). These worms comprise two small groups called acoel and catenulid turbellarians which are now classified in the phylum Platyhelminthes (flatworms) but that, according to some systematists, may not even be related to the more familiar flatworms such as planarians and polyclads. Another of these primitive worm groups is the Gnathostomulida, whose relationships to other phyla of invertebrates have been similarly controversial; by some theories, gnathostomulids are like the ancestors of the flatworms.