Corduliidae, also knowns as the emeralds, emerald dragonflies, or green-eyed skimmers, is a family of dragonflies. These dragonflies are usually black or dark brown with areas of metallic green or yellow, and most of them have large, emerald-green eyes. The larvae are black, hairy-looking, and usually semiaquatic. This family include species called "baskettails", "emeralds", "sundragons", "shadowdragons", and "boghaunters". They are not uncommon and are found nearly worldwide, but some individual species are quite rare. Hine's emerald dragonfly, for example, is an endangered species in the United States.
The Synthemistidae are the family of dragonflies commonly known as tigertails, or sometimes called southern emeralds. This family is part of the superfamily Libelluloidea.
Libelluloidea is a superfamily of dragonflies.