@article {5423, title = {Acoel flatworms: earliest extant bilaterian metazoans, not members of Platyhelminthes.}, journal = {Science}, volume = {283}, year = {1999}, month = {1999}, pages = {1919 - 1923}, keywords = {Paratomella rubra}, author = {Ruiz-Trillo,I and Riutort,M and Littlewood,DTJ and Herniou,EA and Baguna,J} }