Bittacidae Handlirsch, 1906

Lambkin, Kevin J., 2017, Archebittacus exilis Riek — the oldest hangingfly (Insecta: Mecoptera: Bittacidae), Zootaxa 4290 (2), pp. 385-389 : 386

Family Bittacidae Handlirsch, 1906

Wing diagnostic characters. Both wings narrow, around four or more times longer than wide, petiolate or sub-petiolate; costal margin straight; costal space very narrow; R4+5“R4 distinctly arched; R2+3 simple or with two branches; R4+5 with two branches, much more deeply forked than R2+3; R5 convex; CuA extending to at least and usually beyond half wing length; CuA, CuP and anal veins closely spaced and more or less parallel; 2A simple, much shorter than 1A. Forewing with stem of CuA fused for a short distance with the stem of M, not forming a Y-vein with M5; crossveins of the cubital and anal fields limited, at most with four cua-cup, three cup-1a, and two 1a-2a.

Notes. The above list is derived from the Novokshonov (1993), Bechly and Schweigert (2000) and the analysis herein. It does, however, remain somewhat limited by the fragmentary nature of many of the fossil species, the accuracy of their original illustrations, and the fact that most are based on forewings only. The family is most clearly distinguished from its sister family, the extinct Cimbrophlebiidae , by the possession of a short and simple 2A ( Wang et al. 2012).