>700 spp. worldwide
Five introduced species in North America.
"For practical purposes, the family Paradoxosomatidae can be recognized by the dorsal transverse grooves on the 'metazona' of each segment." -- Rowland Shelley
The following characters define the Paradoxosomatidae, according to Nguyen & Sierwald's 2013 catalog:
1. The paranota of the 2nd trunk segment are set distinctly lower than the lateral keels of the collum and the paranota of the 3rd segment, with a few exceptions such as in Chamberlinius.
2. The metaterga feature a transverse sulcus (as noted above by Rowland Shelley)
3. The paraprocts carry two setae each on the paraproct surface, not on their mesal lips.
4. The males of most of the paradoxosomatid genera carry a paired or unpaired anteriad protuberance (termed ‘lamella’ or ‘Sternitfortsatz’ by Attems, 1937) on the 5th sternite.
5. The gonopod aperture is medially constricted, forming almost two separate openings in some genera.
Not native to North America; introduced species Oxidus gracilis is widespread.
Known species in US and Canada: (1)(2)
- Gulf Coast states.
- Widespread, probably all states and provinces
for comparison of A. coarctata
and O. gracilis
Rowland Shelley: Photos of Paradoxosomatidae
. The Myriapoda (Millipedes, Centipedes) Featuring the North American Fauna.
Nguyen A D, Sierwald P (2013) A worldwide catalog of the family Paradoxosomatidae Daday, 1889 (Diplopoda: Polydesmida). Check List 9(6): 1132-1353. Link