Myriapodes

Myriapodes, or myriapods, are a subphylum of arthropods that includes four living groups: centipedes (Chilopoda), millipedes (Diplopoda), pauropods (Pauropoda), and symphylans (Symphyla). They are exclusively terrestrial in most lineages, inhabiting soil, leaf litter, rotting wood, and other moist microhabitats worldwide, where they play roles as detritivores, decomposers, and sometimes predators.

A typical myriapod body is elongated and segmented, with a distinct head bearing antennae and mouthparts, followed by a trunk composed of many segments. In centipedes, there is one pair of legs per trunk segment, and they are usually fast, active predators equipped with forcipules—modified first pair of legs that function as venomous pincers. Millipedes have two pairs of legs per apparent body segment (two legs per diplotergite) due to the fusion of segments, and many are detritivores with slower, more cautious movements. Pauropods and symphylans are smaller and often inhabit soil and leaf litter; pauropods have few legs and a simple body plan, while symphylans resemble small, slender centipedes with numerous legs.

Ecology and life history are diverse: most species are nocturnal and sensitive to desiccation, relying on moist environments. Reproduction is sexual, with eggs laid in soil or leaf litter and juveniles that resemble small adults and acquire additional segments and legs as they molt. Myriapods have a deep fossil history and are among the early colonizers of terrestrial ecosystems, contributing to nutrient cycling and soil structure across many biogeographic regions.