Explanation of Names
From genus
Tipula, that from Latin
tipula (or
tippula) a water spider
(1) (2). (See more on this under genus
Tipula.)
"Crane fly" presumably for long legs, resembling the long legged bird, the
crane.
Numbers
1,517 species in North America cited at
Insects of Cedar Creek, but this number includes three groups that are placed in separate families at BugGuide: Limoniidae, Pediciidae, and Cylindrotomidae.
Identification
terminal (fourth) segment of maxillary palpus elongate, longer than first three segments combined
antennae usually with 13 segments
The above characteristics of Tipulidae (and the differences in Limoniidae mentioned in the See Also section below) were noted in a comment by Chen Young here:
Life Cycle
Larva   Pupa   Female   Male
Remarks
There are two different naming conventions for crane flies: one for Anglo-America and one for Europe. British and American entomologists generally place all crane flies into the family Tipulidae, while European entomologists designate crane flies as making up a super-family, Tipuloidea, with three families, Tipulidae, Limoniidae, and Cylindrotomidae.
See Also
terminal (fourth) segment of maxillary palpus short or subequal to third segment
antennae usually with 14 or 16 segments
Internet References
The Craneflies of Pennsylvania (Chen Young and James Fetzner, Carnegie Museum of Natural History, Pittsburgh)
Catalogue of the Crane Flies of the World classification and searchable database (Pjotr Oosterbroek, U. of Amsterdam and Netherlands Biodiversity Information Facility)
basic information plus crane fly links and literature references (Jon Gelhaus, Academy of Natural Sciences, Philadelphia)
photos and basic info plus links to other crane fly sites (US Environmental Protection Agency)