Composibittacus bipunctatus, Liu, Sulin, Shih, Chungkun, Bashkuev, Alexei & Ren, Dong, 2016

Liu, Sulin, Shih, Chungkun, Bashkuev, Alexei & Ren, Dong, 2016, New Jurassic Hangingflies (Insecta: Mecoptera: Bittacidae) from Inner Mongolia, China, Zootaxa 4067 (1), pp. 65-78 : 68

Composibittacus bipunctatus sp. nov.

(Fig. 1)

Etymology. The species name of bipunctatus indicates the two conspicuous maculae on the wing.

Material. Holotype CNU-MEC-NN2014081.

Horizon and locality. Jiulongshan Formation, latest Middle Jurassic, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China.

Diagnosis. Four oblique crossveins between R1 and R2+3, among which are two pterostigmal crossveins (Pcv’s); Scv about 1/5 as long as the Sc length between Scv and the apex of Sc; the anterior of the ‘bittacid cross’ proximal to the forking of R4+5; four crossveins between Cu1 and Cu2.

Description. Poorly preserved with only one complete forewing and one hind wing, sex unknown.

Basal part of forewing narrow, two conspicuous maculae, one at the forking of Rs, the other more proximal; Sc simple and long, terminating at the anterior margin distal to the forking of R4+5; one subcostal crossvein (Scv) between Sc and R1; R1 running smoothly through the pterostigma with five pterostigmal crossveins (Pcv’s), three between R1 and R2, and two between R1 and R2+3. (Figs. 1C, D); R1 with additional two oblique crossveins to R2+3, both with dark maculae; bifurcation of Rs proximal to the forking point of M; Rs and M with four branches; four crossveins between R2 and R3; R4 and R5 reaching apical margin with at least eight crossveins; M1+2 bifurcating distal to the forking of M3+4, at least three crossveins between M1 and M2; one crossvein between M1 and apical margin, two between M3 and M4 and two between M4 and Cu1; Cu1 and Cu2 almost parallel, four crossveins between them before the basal crossvein of m4-cu1; 1A long, extending past the origination points of Rs from R1 and M from Cu1; 2A terminating in the posterior margin proximal to the originating points of Rs and M; only one crossvein between 1A and 2A present (the other crossvein missing, probably due to preservation); many cells between Rs and M. (Fig. 1D)

Basal part of hindwing narrow; two conspicuous maculae at and near the forking of Rs; Sc untraceable; five pterostigmal crossveins (Pcv’s) present, one oblique crossvein between R1 and R2+3; Rs and M with four branches; two crossveins between R2 and R3; two crossveins between Cu1 and M4; Cu1 and Cu2 almost parallel and three crossveins between them; 1A reaching the posterior margin at the level of halfway between the origination and bifurcation of Rs; part of 2A preserved; many cells between Rs and M (Fig. 1E).

Only six abdominal segments preserved (Figs. 1A, B).

Forewing 28.2 mm long with maximal width of 6.1 mm; hind wing 24.8 mm long with maximal width of 5.6 mm.