Platynus (Dyscolus), Dejean, 1831

Bousquet, Yves, 2012, Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico, ZooKeys 245, pp. 1-1722 : 778-779

Subgenus Dyscolus Dejean, 1831

Dyscolus Dejean, 1831: 279, 437. Type species: Dyscolus memnonius Dejean, 1831 designated by Hope (1838: 105). Etymology (original). From the Greek dyscolos (difficult), probably alluding to the difficulty Dejean had to find the systematic place of the three species he had before him (" formé sur des insectes qui... semblent... former le passage entre les Féroniens et les Troncatipennes, et que je n’ai de même placé dans cette tribu que faute de pouvoir les mettre convenablement ailleurs ") [masculine].

Ophryodactylus Chaudoir, 1842: 832. Type species: Ophryodactylus subviolaceus Chaudoir, 1842 by monotypy. Synonymy established by Moret (1989: 143). Etymology (original). From the Greek ophrys (brow, by extension turned-up margin) and dactylos (finger), alluding to the furrowed sides of the protarsomeres (" tarses antérieurs... tous fortement sillonnés sur les côtés, ce qui fait paraître ceux-ci relevés en bourrelet ") of the adults [masculine].

Paranomus Chaudoir, 1842: 835. Type species: Paranomus lherminieri Chaudoir, 1842 by monotypy. Synonymy established by Moret (1989: 143). Etymology (original). From the Greek para (beside, near, outside) and nomos (usage, law) [masculine].

Pleurasoma Guérin-Méneville, 1844b: 9. Type species: Pleurasoma sulcatum Guérin-Méneville, 1844 by monotypy. Synonymy established by Moret (1989: 143). Etymology (original). From the Greek pleura (side) and soma (body) [neuter]. Note. This genus was described again the same year under the spelling Pleurosoma by Guérin-Méneville (1844d: 1).

Metallosomus Motschulsky, 1865: 304. Type species: Metallosomus virescens Motschulsky, 1865 designated by Jeannel (1948a: 515). Synonymy established by Moret (1989: 143). Etymology. Probably from the Greek metallon (metal) and soma (body) and alluding to the metallic coloration of the adults in the hands of Motschulsky [masculine].

Omiastus Motschulsky, 1865: 306. Type species: Omiastus rutilans Motschulsky, 1865 designated by Lorenz (1998: 129). Synonymy established by Perrault (1992: 276).

Diversity.

About 320 species are listed in this subgenus by Lorenz (2005: 430-433). Of these only five unrelated species are found in southern United States, two of them being endemic ( Platynus falli and Platynus rufiventris ). The other species of the subgenus occur in the Neotropical Region, including the West Indies and the Galapagos Islands.