Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments. There are approximately 12,000 named species classified into 16 orders and around 140 families. Estimates of the true number of species on earth range from 15,000 to as high as 80,000.
About Millipede in brief
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments. They are known scientifically as the class Diplopoda, the name being derived from this feature. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments. There are approximately 12,000 named species classified into 16 orders and around 140 families. Millipedes can be distinguished from the somewhat similar but only distantly related centipedes, which move rapidly, are venomous, and have only a single pair of legs on each body segment. Estimates of the true number of species on earth range from 15,000 to as high as 80,000. Most species of millipede are slow-moving detritivores, eating decaying leaves and other dead plant matter. Some eat fungi or suck plant fluids, and a small minority are predatory. Reproduction in most species is carried out by modified male legs called gonopods, which transfer packets of sperm to females. Most Millipede species defend themselves with a variety of chemicals secreted from pores along the body. Its primary defence mechanism is to curl into a tight coil, thereby protecting its legs and other vital delicate areas on the body behind a hard exoskeleton. First appearing in the Silurian period, millipeds are some of the oldest known land animals. Some members of prehistoric groups grew to over 2 m ; the largest modern species reach maximum lengths of 27 to 38 cm.
The longest extant species is the giant Africanmillipede. Among myriapods, millIPedes have traditionally been considered most closely related to the tiny pauropods, although some molecular studies challenge this relationship. The living members of the Diplipoda are divided into sixteen orders in two subclasses. The basal subclass Penicillata contains a single order, Polyxenida. All othermillipedes belong to the subclass Chilognatha consisting of two infraclasses: Pentazonia, containing the short-bodied pill millipeded, and Helminthomorpha, containing the great majority of the species. The placement and positions of extinct groups is not yet resolved and not fully resolved. After the known from fossils, only the largest known terrestrial animals, the Archipolypoda, are all extinct. The largest known invertebrates are the Arthrotea, which contain the largestknown terrestrial animals and contain the smallest invertebrate species, P. de Blainville de Gervais. The earliest known land creatures are the Pterosauridae, which are among the first animals to have colonised land during the SilURian period and probably ate mosses and primitive vascular plants. The name \”Millipede\” derives from the Latin for \”thousand feet\”, although no known species has 1,000; the record of 750 legs belongs to Illacme plenipes.