Pill millipedes are any members of two living orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), also called pillbugs or "roly-polies". However, millipedes and woodlice are not closely related ; rather, this is a case of convergent evolution.
Glomerida is an order of pill-millipedes found primarily in the Northern Hemisphere. Also known as northern pill millipedes, they superficially resemble pill-bugs or woodlice, and can enroll into a protective ball. They have twelve body segments, 17 to 19 pairs of legs, and males have enlarged rear legs involved in mating. The order includes about 30 genera and at least 280 species, including Glomeris marginata, the common European pill-millipede. The order contains members in Europe, South-east Asia and the Americas from California to Guatemala. Although historically considered closely related with the similar sphaerotheriidans that also enroll, some DNA evidence suggest they may be more closely related to glomeridesmidans, a poorly known order that does not enroll.
Glomeris is a genus of pill millipedes that belongs to the family Glomeridae and order Glomerida. The genus Glomeris is the largest within the family Glomeridae, comprising about 100 species along with a few hundred subspecies, varieties, forms, or genetic aberrations. The genus is primarily distributed in Europe, but can also be found in the Canary Islands, North Africa, and North-western Anatolia.
Sphaerotheriida is an order of millipedes in the infraclass Pentazonia, sometimes known as giant pill millipedes. They inhabit Southern Africa, Madagascar, South and Southeast Asia, Australia and New Zealand. Like the Northern Hemisphere pill millipedes of the order Glomerida, these millipedes can roll into a ball when disturbed. When they are rolled-up, most sphaerotheriidans reach a maximum size of a cherry or golf ball, but some species from Madagascar can even reach the size of an orange. When rolled-up, predators are unable to unravel giant pill millipedes since the margins of their second and last dorsal plates fit perfectly into one another, creating a sealed ball. A few giant pill millipede species are able to produce sound, the only millipedes known to do this. This order of millipedes is also unique in that some African species are used for medicinal purposes.
Julidae is a family of millipedes in the order Julida, containing more than 600 species in around 20 genera. Its members are largely confined to the Western Palaearctic, with only a few species extending into the Oriental and Afrotropical realms. They are united by a characteristic form of the mouthparts, and are classified in the superfamily Juloidea of the order Julida, alongside the families Trichoblaniulidae, Rhopaloiulidae and Trichonemasomatidae.
Chordeumatida is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as sausage millipedes, they grow and develop through a series of moults, adding segments until they reach a fixed number in the adult stage, which is usually the same for a given sex in a given species, at which point the moulting and the addition of segments and legs stop. This mode of development, known as teloanamorphosis, distinguishes this order from most other orders of millipedes, which usually continue to moult as adults, developing through either euanamorphosis or hemianamorphosis.
Zephronia is a genus of giant pill millipedes in the family Zephroniidae. This genus includes 47 species distributed throughout N. India, Myanmar, Thailand, Malayan Peninsula, Java, Sumatra and Borneo.
Glomeris klugii is a species of pill millipede within the genus Glomeris and family Glomeridae. The species is highly variable in colouration, with more than 40 varieties and subspecies identified, each displaying unique colour patterns. The diverse colour patterns of G. klugii can be visually striking, and certain patterns are geographically restricted, leading to the species being associated with numerous taxonomic synonyms.
Glomeris connexa is a species of pill millipede within the genus Glomeris and family Glomeridae.
Anthroleucosomatidae is a family of millipedes in the order Chordeumatida. These millipedes range from 3.5 mm to 28 mm in length. Adult millipedes in this family have 26, 28, 30, or 31 segments. This family includes Metamastigophorophyllon martensi, notable as the only chordeumatidan species with 31 segments. There are about 38 genera in Anthroleucosomatidae.
Craspedosomatidae is a family of millipedes in the order Chordeumatida. Most adult millipedes in this family have 30 segments, but some have only 28. There are at least 30 genera and 210 described species in Craspedosomatidae.
Anamastigona is a genus of millipedes in the family Anthroleucosomatidae. There are about 20 described species in Anamastigona, found mainly in Europe and the Middle East.
Ophyiulus is a genus of millipedes in the family Julidae. There are more than 30 described species in Ophyiulus.
Trichopolydesmidae is a family of millipedes belonging to the order Polydesmida. This family includes two genera notable for featuring sexual dimorphism in segment number: adult females in these genera have the 20 segments usually found in this order, but adult males have only 19. This family also includes the species Deharvengius bedosae, notable for being among the very few species in this order to feature adults with only 18 segments rather than the 20 segments usually found in polydesmids.
Attemsiidae is a Palaearctic family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family have 30 segments.
Glomeridellidae is a family of millipedes belonging to the order Glomerida. The adult males in this family have two pairs of telopods rather than the single pair found in other families in this order.
Trachysphaera lobata, also known as the sand pill millipede, is a species of pill millipede within the genus Trachysphaera and family Glomeridae.
Glomeris ornata, is a species of pill millipede within the genus Glomeris and family Glomeridae.
Glomeris primordialis, is a species of pill millipede within the genus Glomeris and family Glomeridae. The species is locally endemic to the Biellese Alps of Northern Italy.
Glomeris punica, is a species of pill millipede belonging to the genus Glomeris and the family Glomeridae.
