Acoel flatworms are small marine worms traditionally considered to belong to the phylum Platyhelminthes. However, molecular phylogenetic analyses suggest that acoels are not members of Platyhelminthes, but are rather extant members of the earliest diverging Bilateria. This result has been called into question, under suspicions of a long branch attraction (LBA) artefact. Here we re-examine this ...

Nucleotide sequences of 18S ribosomal RNA from 71 species of Platyhelminthes, the flatworms, were analyzed using maximum likelihood, and the resulting phylogenetic trees were compared with previous phylogenetic hypotheses. Analyses including 15 outgroup species belonging to eight other phyla show that Platyhelminthes are monophyletic with the exception of a sequence putatively from Acoela sp., ...

Flatworms are one of the most diverse groups within Lophotrochozoa with more than 20,000 known species, distributed worldwide in different ecosystems, from the free-living organisms in the seas and lakes to highly specialized parasites living in a variety of hosts, including humans. Several infections caused by flatworms are considered major neglected diseases affecting countries in the America...

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Aim Freshwater planarians may have a wide geographical range despite their assumed low vagility. Found across four continents, Dugesia either an ancient origin on large palaeo landmass, followed by colonisation in different regions before continental fragmentation, or more recent and subsequent transoceanic dispersal. We seek to resolve between these two hypotheses. Location Africa, Eurasia Aus...

The phylum Platyhelminthes (flatworms) consists of approximately 50,000 different species that populate a remarkable variety of niches (Littlewood and Bray, 2001). In addition to free-living forms, it encompasses parasitic organisms responsible for inflicting debilitating diseases upon hundreds of millions of people throughout the world (see World Health Organization fact sheet 115 at http://ww...