Eomeropidae is a family of aberrant, flattened scorpionflies represented today by only a single living species, Notiothauma reedi, known from the Nothofagus forests in southern Chile, while all other recognized genera in the family are known only as fossils, with the earliest definitive fossil known from Liassic-aged strata, and the youngest from Paleogene-aged strata.

Mecoptera is an order of insects in the superorder Holometabola with about six hundred species in nine families worldwide. Mecopterans are sometimes called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals raised over the body that look similar to the stingers of scorpions, and long beaklike rostra. The Bittacidae, or hangingflies, are another prominent family and are known for their elaborate mating rituals, in which females choose mates based on the quality of gift prey offered to them by the males. A smaller group is the snow scorpionflies, family Boreidae, adults of which are sometimes seen walking on snowfields. In contrast, the majority of species in the order inhabit moist environments in tropical locations.