Nce other, more distant platyhelminth relationships: in this tree, Proseriata becomes the earliest-divergent taxon of Euneoophora, with Rhabdocoela as the sister for the remaining taxa, with sturdy (0.96) bootstrap help. The significance of this impact remains, at present, unclear.Implications for the origin of platyhelminth parasitismPre-cladistic classifications emphasized the separation of the parasitic flatworms from their free-living ancestors (the paraphyletic [Ehlers, 1985] `Class Turbellaria’), in recognition in the vast phenetic differences involving these lineages. Our identification of B. semperi because the closest free-living relative of Neodermata, along with the nuclear genomic evidence we present for Cercomeromorpha, will support to narrow this artificial gap, by clarifying the relevant comparisons that really should be created, and by setting taxonomic priorities for future research. Bothrioplanida and Neodermata may possibly, as an illustration, bear proof of typical ancestry 
in elements of their morphology: at the ultrastructural level, B. semperi PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21352533 resembles Neodermata both inside the structure of its excretory method (namely, its protonephridial flame bulbs, that are composed of two cells with extensions that interdigitate to type an ultrafiltration weir in considerably the same way in each taxa [Kornakova, 2010]), at the same time as inside the structure of its R-268712 web monociliary epidermal sensory receptors (which bear an electron-dense collar in both taxa [Kornakova and Joffe, 1996]). Additional morphological investigation in the somewhat obscure B. semperi might reveal other shared derived characters of these taxa, although certain character systems may possibly prove elusive (e.g., spermatogenesis within a purportedly parthenogenetic species). Fortunately, knowledge of Bothrioplanida require not necessarily be restricted to B. semperi, provided the proof for at least one undescribed putative Bothrioplana species (Kawakatsu and Mack-Fira, 1975); additional representatives might also be recovered by studies of cryptic molecular diversity and continued exploratory taxonomic surveys of freshwater microturbellarians, which stay poorly known outdoors of the Palearctic (Artois et al., 2011). Indeed, a new species of Bothrioplanida apparently capable of normal spermatogenesis has been lately reported from mainland China (Ning et al., In press). Comparison amongst Bothrioplanida plus the extant Neodermata may also extend beyond the look for synapomorphies: they might inform hypotheses on the route by which the earliest vertebrate-parasitic associations of Platyhelminthes arose. As a cosmopolitan species able to colonize temporary, chemically diverse, and spatially isolated freshwaters, B. semperi seems to be remarkably effectively adapted to frequent long-distance passive dispersal (possibly by way of vertebrate, in particular waterfowl, vectors [Sluys and Ball, 1985; Artois et al., 2011]), an ecological challenge no less than analogous towards the sweepstakes game that every single succeeding generation of parasite plays during the colonization of a new host. It’s hence tempting to speculate that at least some adaptations to these equivalent ecological challenges could happen to be present in the most recent widespread ancestor of Bothrioplanida and Neodermata, and may have `pre-adapted’ early neodermatans to a parasitic way of life. For example, if stem Neodermata possessed a resistant, presumably quinone-tanned egg capsule equivalent to that made use of by B. semperi in passive dispersal, this could have facilitated enteric infection early within the history of.