Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Order Polydesmida - Flat-backed Millipedes

Millipede_6322 - Oxidus gracilis unknown millipede found near Forks Creek - Harpaphe haydeniana Unknown millipede, possibly polydesmidae? Millipede - Oxidus gracilis millipede - Apheloria virginiensis Scytonotus species? - Scytonotus Apheloria virginiensis fungus - Apheloria virginiensis Boraria Stricta? - Apheloria tigana
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Myriapoda (Myriapods)
Class Diplopoda (Millipedes)
Order Polydesmida (Flat-backed Millipedes)
Explanation of Names
Polydesmida Leach 1815
Numbers
10 families in our area • ~5,750 spp. in >1,200 genera of 44 families total(1)
Size
3‒130 mm
Identification
18‒22 body rings (usually 20). Dorsal groove absent. Large paranota give a flattened appearance to many species, although paranota lacking in some species. Members of some families vividly colored with red, yellow, orange and black. Eyes absent.
Remarks
The largest millipede order, and the only one that includes producers of cyanogenics that are converted into hydrogen cyanide as a defense.(2) Many species possess these compounds (Shear 2015).
See Also
Some Chordeumatida (e.g. in Rhiscosomididae, Striariidae, Tingupidae) have prominent paranota and a similar "flat-back" appearance, but possess >25 body segments.
Internet References
Works Cited
1.Catalogue of Life
2.Centipedes and Millipedes, with an Emphasis on North American Fauna
Rowland M. Shelley. 1999. Emporia State University.