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Order Polydesmida - Flat-backed Millipedes

Small Harpaphe haydeniana? Millipede - Asiomorpha coarctata Elk Grove Millipedes - Oxidus gracilis Mating Milipedes? - Pseudopolydesmus serratus Apheloria? Millipede 1 - Apheloria virginiensis Millipedes Multiple site 2 Hayrock - Oxidus gracilis St. Andrews beaver chewed Liquidambar styraciflua with millipedes in resin 2022 3.1 - Oxidus gracilis
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Myriapoda (Myriapods)
Class Diplopoda (Millipedes)
Order Polydesmida (Flat-backed Millipedes)
Numbers
About 28 families worldwide.
10 families in North America.
Size
3-130mm
Identification
18 to 22 body rings. 20 body rings is the most common. Dorsal groove absent. Large paranota (wing-like lateral extensions of the body segment) 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 are absent.
Remarks
The largest millipede order, and the only one that includes producers of cyanogenics that are converted into hydrogen cyanide as a defense.(1) Many species appear to 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.
Print References
Shear, W. A. 2015. The chemical defenses of millipedes (diplopoda): Biochemistry, physiology and ecology. Biochemical Systematics and Ecology 61: 78-117. http://dx.doi.org/10.1016/j.bse.2015.04.033
Internet References
Wikipedia. Polydesmida
Works Cited
1.Centipedes and Millipedes, with an Emphasis on North American Fauna
Rowland M. Shelley. 1999. Emporia State University.