Xenoturbella 's molluscan relativesṫ

Despite detailed morphological studies, the phylogenetic relationships of Xenoturbella bocki Westblad 1949 have remained unclear. The marine, worm-like X. bocki was first described as an acoel flatworm. Later it was proposed to be a deuterostome, and most recently as the sister taxon of the Bilateria. Here we present DNA sequence data that place X. bocki within the protostome clade Eutrochozoa.