Diplopoda

Definition

A class of myriapod arthropods comprising the millipedes, characterized by having two pairs of legs on most body segments (except the first three or four and the last one or two). Each apparent body segment is actually a diplosegment formed by the fusion of two ancestral segments. Diplopoda is the largest class of Myriapoda, with approximately 12,000 described species in 16 orders, ranging from minute soil-dwellers to giant tropical species exceeding 30 cm in length. Most are slow-moving detritivores or herbivores, distinguished from the carnivorous, single-legged Chilopoda (centipedes) by leg number, body shape, and feeding ecology.

Etymology

New Latin, from Greek diploos "double" + pous "foot" + -us suffix, referring to the paired legs per segment

Example

The Australian millipede Eumillipes persephone, described in 2020, holds the record for most legs among Diplopoda with up to 1,306 legs on 330 segments, finally justifying the "millipede" name.

Synonyms

• Millipedes

Related Terms

• Myriapoda
• Chilopoda
• diplosegment
• Detritivore
• Arthropoda

Usage Notes

Diplopoda is treated as a plural proper noun in formal taxonomy (the class Diplopoda), though often used with singular verbs in general writing. Contrast with Chilopoda (centipedes), which have one leg pair per segment and are primarily predatory. The class is divided into three major clades: Penicillata (bristly millipedes), Pentazonia (pill millipedes), and Helminthomorpha (worm-like millipedes, the most diverse group).