Trichopolydesmidae Verhoeff, 1910

Golovatch, Sergei I., 2013, A reclassification of the millipede superfamily Trichopolydesmoidea, with descriptions of two new species from the Aegean region (Diplopoda, Polydesmida), ZooKeys 340, pp. 63-78 : 72-73

Family Trichopolydesmidae Verhoeff, 1910

Diagnosis.

Body polydesmoid, only exceptionally paraterga deeply lobulate laterally. Sphaerotrichomes only rarely present. Antennomere 5 sometimes devoid of sensilla distodorsally. Sphaerotrichomes only sometimes present.

Gonopod aperture large, transversely oval, with exposed to deeply sunken gonocoxae. Gonocoxae subglobose, usually with normal, tube-shaped cannulae, from small to rather large while telopodites from strongly exposed to concealed inside a considerable central gonocoel; prefemoral portion tends to be orientated transversely to main body axis, only occasionally somewhat to clearly shortened and thus resembling the condition observed in Polydesmoidea ; acropodite tri-, bi- or uniramous, usually directed cephalad or cephalomesad; solenomere mostly evident, simple, only seldom a short tooth, more often long, distal in location, either stout or slender/flagelliform. Normally neither an accessory seminal chamber nor a hairy pulvillus, only exceptionally with a primordial accessory seminal chamber. Caucasodesmus Golovatch, 1985 (Caucasus and Crimea) is aberrant in having no sensilla on antennomeres 5 and no cannulae or seminal grooves.

Type genus: Trichopolydesmus Verhoeff, 1898.

Remarks.

The family Mastigonodesmidae Attems, 1914, based on Mastigonodesmus Silvestri, 1898 (ca 8 eight species in the western Mediterranean), is sometimes regarded as a synonym of Polydesmidae Leach, 1815 ( Hoffman 1980, Simonsen 1990), apparently because the gonopod prefemoral part is shortened, but, due to globose gonocoxae and a peculiar, parabasal, long and coiled solenomere, it seems to be far more similar to that in trichopolydesmoids. The Mastigonodesmidae seems to also contain the monobasic genus Ingurtidorgius , which is sometimes treated as a subfamily of its own, because its male shows a peculiar hook on the mentum and totally suppressed lamellae linguales, coupled with a non-coiled, but flagelliform solenomere. Since the latter character is shared with Trichopolydesmus , contrary to some recent opinions ( Mauriès 1983, Golovatch 2011), it seems best to also merge Mastigonodesmidae with Trichopolydesmidae , syn. n.

The same applies to the family Macrosternodesmidae , which basically fails to differ from Trichopolydesmidae , but simply tends to encompass quite a few genera with small to medium-sized, invariably globose gonocoxae and strongly exposed, often complex telopodites. Since the purely Nearctic nominate family Nearctodesmidae shares the gonopod conformation with Macrosternodesmidae , and it has sometimes been treated as only a subfamily or even a possible synonym of the latter family, I am inclined to treat these two latter families as synonyms of Trichopolydesmidae as well,syn. n.

Shelley (1994) gave a detailed morphological description of nearctodesmids and revived their family status, contrary to Hoffman (1982) who had synonymized the Nearctodesmidae with Macrosternodesmidae . Later, however, apparently following Shelley (1994), Hoffman (1999) also considered the Nearctodesmidae as a distinct family.

The diversity of gonopod structural plans in nearctodesmids+macrosternodesmids ( Shelley 1994, Shear and Shelley 2007) appears to be quite modest and uniform, since all of their constituent genera such as Nearctodesmus Silvestri, 1910, Kepolydesmus Chamberlin, 1910, Bistolodesmus Shelley, 1994, Tidesmus Chamberlin, 1943 etc. show clearly transverse and elongated prefemoral portions which are set subrectangular to the subparallel, usually bi- or triramous, elaborate, normally clearly curved and well exposed acropodites. The gonocoel if any is moderate at most. According to Shear and Shelley (2007), the differences between these “families” lie only in the number and location of branches on the acropodite, a distinction that by far fails to exceed the diversity of gonopod plans observed among the South American fuhrmannodesmids alone ( Golovatch 1994).

Contents and distribution.

Thus refined, the Trichopolydesmidae currently contains ca 20 genera and about 60 species in the Holarctic, as well as ca 55 genera and about 80 species in the tropics.