This site is intended as an online repository for taxonomic and phylogenetic information on the Macrostomorpha, a basal group of free-living flatworms, with particular emphasis for the genus Macrostomum. According to the current phylogenies the Macrostomorpha are the most basal taxon of the Rhabditophora, which encompass all free-living flatworms (except the Acoelomorpha and the Catenulida) and all the parasitic flatworms.
One problem with these (and many other) free-living flatworms, is that they are tiny and very fragile creatures. They are often only 1mm long and one therefore cannot usually perform DNA sequence analyses and have a reference specimen at the same time (as complete worms are used for DNA extraction).
Detailed photomicrographic documentation of the living worm will often be the only reference left of a sequenced specimen. Moreover, the classical deposited type specimens are serial sections on slides, which are informative for detailed anatomical studies, but which are not useful for species identification in the field. Detailed photomicrographic documentation, appropriately organised, annotated and accessible through the web, will generally be much more informative for the general biologist that encounters these creatures.