Turbellarian taxonomic database

Plagiostomidae Plagiostomum

In this database, we follow the traditional taxonomy by keeping Plicastoma Graff, 1904, Plagiostomum Graff, 1882 and Vorticeros Schmidt, 1852 as separate genera. Norén & Jondelius (1999 (citation); 2002 (citation)) clearly showed however that this makes Plagiostomum paraphyletic. Therefore , in 1999, Norén & Jondelius  propose to unite three genera in one, monophyletic taxon Plagiostomum. However, if this view is followed, the new taxon should be called Vorticeros, because of considerations of priority. In 2004, Noren (citation) did an anlysis fllowing the description of several new species, and found out that the taxonomy was even more complicated, especially regarding the position of Torgea. 
Because of the above, we decide provisionally to keep Plagiostomum, Vorticeros and Plicastoma separate. However, we follow Noren (2004) in synonymising Paramultipeniata with Plagiostomum. 

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Notes from synonyms