Polydesmoidea, Leach, 1815

Shear, William A., 2012, Snoqualmia, a new polydesmid milliped genus from the northwestern United States, with a description of two new species (Diplopoda, Polydesmida, Polydesmidae), Insecta Mundi 2012 (238), pp. 1-13 : 1-2

Polydesmoidea and Trichopolydesmoidea

Unfortunately at the present time the superfamilies Polydesmoidea and Trichopolydesmoidea, and their constituent families, are in a state of flux and confusion. Neither taxon has been unequivocally diagnosed, and both have served as trash bins for families and genera that have either been poorly described originally or have not been studied since their first proposal. In particular the Trichopolydesmoidea and the family Trichopolydesmidae Verhoeff 1910 have been expanded to include many tropical species that probably do not form a monophyletic group with the type genus Trichopolydesmus Verhoeff 1898 , monotypic, native to Romania, and itself poorly studied. Hoffman’s opinion that Trichopolydesmidae are a small family limited to a few species in eastern Europe is probably correct, but this leaves behind more than 50 genera, many monotypic, uncomfortably agglutinated in the family Fuhrmannodesmidae Broleman 1916 ( Hoffman 1999) . In North America, however, the situation has recently been clarified somewhat by a rediagnosis of the supposedly trichopolydesmoid family Macrosternodesmidae by Shear and Shelley (2007), though it remains unsettled if this name is or is not a senior synonym of Nearctodesmidae Chamberlin and Hoffman 1950 , as proposed by Simonsen (1990).

In the case of the Polydesmoidea , the included families Cryptodesmidae Karsch 1879 , Haplodesmidae Cook 1895 , Doratodesmidae Cook 1896 , and Opisotretidae Hoffman 1999 appear to be well-diagnosed and probably represent monophyletic units. Polydesmidae Leach 1815 has not been so fortunate. It contains at present elements that belong elsewhere, some of them not even to be placed in the same superfamily. For example, Archipolydesmus Attems 1898 is obviously a macrosternodesmid ( Abrous-Kherbouche and Mauriès 1996). In various papers on the Antillean fauna, Loomis (i.e. 1934) added such diverse genera to Polydesmidae that it became a meaningless wastebasket. Thus I do not agree with the assertion of Simonsen (1990) that Polydesmidae are probably monophyletic. Furthermore, within the polydesmid mélange, genera such as Epanerchodus Attems 1901 , with more than 60 species ranged in eight subgenera (most of which have been ignored by systematists recently describing new species in the genus) seems, from a scan of the literature, to be polyphyletic. Even more so is the genus Polydesmus Latrielle 1803 , with more than 100 named species in fully 26 subgenera, some of which surely represent full genera. Many of the species have multiple named subspecies and varieties. In North America, where neither genus is indigenous, the situation is simpler by far, but remains potentially daunting because of a substantial number of undescribed taxa.