01411nas a2200169   4500008004100000245011400041210006900155300001200224490000700236520078100243100001901024700001501043700001701058700001401075700001401089856013801103       2004                        eng d00aMitochondrial genome data support the basal position of Acoelomorpha and the polyphyly of the Platyhelminthes0 aMitochondrial genome data support the basal position of Acoelomo  a321-3320 v333 aWe determined 9.7. 5.2. and 6.8kb, respectively, of the mitochondrial genomes of the acoel Paratomella rubra, the nemertodermatid Nemertoderma westbladi, and the free-living rhabditophoran platyhelminth Microstomum lineare. The identified gene arrangements are unique among metazoans, including each other, sharing no more than one or two single gene boundaries with a few distantly related taxa. Phylogenetic analysis of the amino acid sequences inferred from the sequenced genes confirms that the acoelomorph flatworms (acoels + nemertodermatids) do not belong to the Platyhelminthes, but are, instead, the most basal extant bilaterian group. Therefore, the Platyhelminthes, as traditionally constituted, is a polyphyletic phylum. (C) 2004 Elsevier Inc. All rights reserved.1 aRuiz-Trillo, I1 aRiutort, M1 aFourcade, HM1 aBaguna, J1 aBoore, JL  uhttps://acoela.myspecies.info/en/content/mitochondrial-genome-data-support-basal-position-acoelomorpha-and-polyphyly-platyhelminthe-0