A thousand-legged name that waited until 2020 to come true
Millipedes belong to class Diplopoda: most body rings carry two pairs of legs because each ring is a fused pair of segments. Roughly twelve thousand named species fill sixteen orders, yet none was known to reach a thousand feet until Eumillipes persephone, found in 2020, topped thirteen hundred.
Latin mille and pes give the folk name, but true counts run from about eleven segments to more than three hundred, with body lengths from two millimetres to around thirty-five centimetres. Pill millipedes roll into tight balls; worm-like helminthomorphs dominate species counts. Most are slow detritivores of rotting leaves, though some take fungi or plant fluids. Defence often means coiling behind a hard cuticle or spraying chemicals from body pores; Motyxia species even make cyanide and glow.
They rank among the earliest land animals, appearing in the Silurian. Body fossils include Wenlock material dated near 427 million years ago. Carboniferous Arthropleura exceeded two metres and remains the largest known terrestrial invertebrate—later work favours low competition over high oxygen as the main size driver. Devonian fossils already show ozopores, the earliest clear chemical-defence glands. Living giants such as Archispirostreptus gigas reach roughly twenty-seven to thirty-eight centimetres.
Centipedes look similar but are distant cousins: one leg pair per segment, venomous hunters with long antennae and poison claws, splitting from millipede ancestors some 450 to 475 million years ago. Diplopodology—the study of millipedes—traces taxonomy from Linnaeus’s 1758 Julus species through de Blainville’s 1844 Diplopoda. Poor dispersal and humid habitats keep many lineages local, so true diversity may run from fifteen thousand to as high as eighty thousand species. Chilognaths harden their exoskeletons; soft-bodied bristle millipedes alone keep the basal Penicillata subclass.
Source: Millipede
