Here are the 15 recognized orders of millipedes. It is almost impossible to identify the species of many millipedes - identification is based upon minute characteristics, and the systematics of millipedes is still undergoing a much-needed revision. Those orders present in North America are noted with an asterisk (*). Information on this page gleaned from references cited below.
Polyxenida* - small bristly millipedes, have no calcified cuticle (soft bodies).
Glomeridesmida - pentazonian, but not pill, millipedes. Tropical but absent in Africa.
Glomerida* - Palaeoarctic pill millipedes found in Europe, Asia, North Africa, and North America. Have 12 segments.
Sphaeriotheriida - giant pill millipedes with 13 segments. Found in Australasia, southern Africa, and Madagascar.
Polyzoniida* - Elongated millipedes, arched dorsally. Some species have long beak used to suck juices from roots. Found in North America, Caribbean, Europe, and parts of Asia.
Platydesmida* - Superficially like polydesmids. Elongated with generally flattened bodies, head usually subtriangular. Found in North America, Europe, parts of Asia and Indonesia.
Julida* - cylindrical millipedes, usually small. Many temparate-zone species. Found in North and Central America, Europe, and parts of Asia.
Spirostreptida* - large cylindrical millipedes, abundant in tropics, some are desert species. Occur in Africa, Asia, Australia, North America and parts of South America.
Spirobolida* - large cylindrical millipedes, both tropical and temperate species. Found in North and South America, parts of Africa, Asia, and Australia.
Polydesmida* - Short bodied, flatbacked millipedes, many are colorful. The only millipedes that secrete cyanide.
Chordeumatida* - Short bodied, often tergal keels, quadrangular flat-backs, with tapering towards the end. Spinnerets. Found in North and Central America, Europe, north Africa, Madagascar, parts of Asia, Indonesia, Australia, and New Zealand.
Stemmiulida - Long-bodied, tropical, 39-60 rings. Spinnerets. Found in Mexico and Central America, central Africa, India, and New Guinea.
Callipodida* - Long bodied, 40+ rings. Cylindrical often with ridges and crests. Found in North America, Europe, and Asia.
Siphonophorida* - Narrow body, "beak" on head. Includes millipedes with the most legs. Found in North and South America, south Africa, and southeast Asia.
Siphoniulida - Rare millipedes known only from Guatemala, Mexico, and Sumatra. Cylindrical with prominent "beak" on head.
- Blower, J.G., ed. 1974. Myriapoda. Symposia of the Zool. Soc. of London, No. 32. Academic Press.
- Blower, J.G. 1985. Millipedes: keys and notes for the identification of the species. Avon, UK: Bath Press.
- Shear, W.A. 1999. Millipeds. American Scientist 87(May-June): 232-239.
- Shelley, R.M. 1999. Centipedes and millipedes. Kansas School Naturalist 45(3): 1-16.