; class Insecta, subclass Pterygota)
Order of primitive insects, the earliest fossils of which are found in the upper Carboniferous coal measures of Commentry (France). These slender-bodied insects have two pairs of large, glassy wings, and large, prominent eyes. They usually hunt on the wing, taking swarming flies and other flying insects. Odonates are unique in possessing two sets of genitalia (see accessory genitalia). The nymphs are aquatic, and catch prey with a prehensile organ (called the mask) derived from the labia (see labium). Despite their fearsome common names, these beautiful insects are not dangerous to large animals. About 5000 species are known, with a cosmopolitan but mainly tropical distribution.
Subjects: Zoology and Animal Sciences.