Crane fly is a common name referring to any member of the insect family Tipulidae, of the order Diptera, true flies in the superfamily Tipuloidea. Cylindrotominae, Limoniinae, and Pediciinae have been ranked as subfamilies of Tipulidae by most authors, though occasionally elevated to family rank. In the most recent classifications, only Pediciidae is now ranked as a separate family, due to considerations of paraphyly. In colloquial speech, crane flies are sometimes known as mosquito hawks or daddy longlegs, a term also used to describe opiliones or the family Pholcidae, both of which are arachnids. The larvae of crane flies are known commonly as leatherjackets. Crane flies are found worldwide, though individual species usually have limited ranges. They are most diverse in the tropics, and are also common in northern latitudes and high elevations. The Tipulidae is one of the largest groups of flies, including over 15,000 species and subspecies in 525 genera and subgenera. Most crane flies were described by the entomologist Charles Paul Alexander, a fly specialist, in over 1000 research publications. An adult crane fly, resembling an oversized mosquito, typically has a slender body and stilt-like legs that are deciduous, easily coming off the body. The wingspan is generally about 1.0 to 6.5 cm, though some species of Holorusia can reach 11 cm. The antennae have up to 19 segments. It is also characterized by a V-shaped suture on the back of the thorax and by its wing venation. The rostrum is long; in some species it is as long as the head and thorax together.