Teloanamorphosis
Guides
Callipodida
Crested Millipedes
Callipodida is an order of millipedes comprising approximately 130 species across three extant suborders and seven families. Members are characterized by elongated bodies with 40–60 segments, reaching up to 100 mm in length, and often display distinctive dorsal crests or ridges. The order exhibits a disjunct distribution across the Northern Hemisphere, with populations in North America, Europe, western Asia, southern China, and Southeast Asia. Sexual maturity is achieved through teloanamorphosis, with males possessing a single pair of gonopods derived from the seventh leg pair.
Chordeumatida
Sausage Millipedes, Spinning Millipedes
Chordeumatida is a large order of millipedes containing over 1,100 species, commonly known as sausage millipedes or spinning millipedes. Members of this order are distinguished by their teloanamorphic development—adding segments through molts until reaching a fixed adult number, after which molting ceases. They are notable for possessing spinnerets on their telsons that produce silk used to construct protective chambers for molting and egg-laying. The order exhibits considerable morphological diversity, with species ranging from 3.5 to 42 mm in length and displaying both cylindrical and flat-backed body forms.
Polydesmida
Flat-backed Millipedes
Polydesmida is the largest order of millipedes, containing over 5,000 described species. Members are commonly known as flat-backed millipedes due to the presence of lateral keels (paranota) on most body segments. This order includes all millipedes known to produce hydrogen cyanide (HCN) as a chemical defense. Polydesmids are found on every continent except Antarctica and exhibit the highest morphological diversity among millipede orders. They are characterized by a unique developmental mode called teloanamorphosis, in which adults reach a fixed number of segments and cease molting.