Composibittacus reticulatus, 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 : 68-71

Composibittacus reticulatus sp. nov.

( Figs. 2 , 3 )

Etymology. The species name is derived from the Latin word “ reticulatus ” (reticular), highlighting the net-like venation due to many crossveins.

Material. Holotype, CNU-MEC-NN2014082 p/c, part and counterpart. Paratype, CNU-MEC-NN2014083 with a well-preserved hind wing, partial forewings and parts of legs.

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

Diagnosis. Four oblique crossveins present between R1 and R2+3, among which are three pterostigmal crossveins (Pcv’s) (vs. two for C. bipunctatus sp. nov.); Scv about 0.4 to 0.6 times (vs. 0.2 times) as long as the Sc length between Scv and the apex of Sc; the ‘bittacid cross’ nearly in alignment (vs. the anterior part of the ‘bittacid cross’ proximal to the forking of R4+5); five crossveins (vs. four) between Cu1 and Cu2.

Remarks. Composibittacus reticulatus sp. nov. ( Figs. 2 , 3 ) is assigned to Composibittacus gen. nov. based on the following generic diagnostic characters: Sc reaching the anterior margin distal of the forking of R4+5; one crossvein between C and Sc; five pterostigmal crossveins between R1 and R2 and R1 and R2+3; the ‘bittacid cross’ nearly in alignment; 1A reaching the posterior margin proximal to the bifurcation of Rs; 2A present.

Description. Poorly-preserved holotype with one complete forewing and parts of thorax and legs. Pronotum, mesonotum, metanotum, mesocoxa, metacoxa, trochanter visible in lateral view; legs with femurs only, densely covered with short setae. ( Figs. 2 A, B, C, E)

Forewing with Sc long, reaching the anterior margin of the wing distal to the bifurcation of R4+5; one crossvein (Scv) present between Sc and R1; Scv about 0.4 (holotype) to 0.6 (paratype) times as long as the Sc length between Scv and the apex of Sc; R1 simple, running through the pterostigmal area with five pterostigmal crossveins (Pcv’s) ( Fig. 2 D); one (holotype) or two (paratype) additional crossveins between R1 and R2+3; R and M with four branches; four crossveins between R2 and R3 and three crossveins between R2+3 and R4; bifurcation of Rs proximal to the forking of M; the ‘bittacid cross’ nearly in alignment; many cells between Rs and M; crossveins X or Y-shaped, present in apical area of Rs and M; two crossveins between M4 and Cu1; Cu1 and Cu2 parallel with five crossveins between them; 1A reaching the posterior margin proximal of the bifurcation of Rs, 2A ending at the level of the origination of M, two crossveins between 1A and 2A ( Figs. 2 C, 3B).

Hind wing of paratype with Sc reaching the anterior margin proximal to the bifurcation of R4+5; R1 running smoothly through the pterostigmal area; three Pcv’s present, an oblique crossvein between R1 and R2+3; four crossveins between R2 and R3; Rs and M bifurcating into four branches; Rs bifurcation proximal to the forking of the M; ‘bittacid cross’ nearly in alignment; Cu1 and Cu2 parallel with three crossveins between them; 1A long, reaching the posterior margin proximal to the forking of Rs; 2A present, ending at the posterior margin slightly proximal to the origination points of Rs and M; many cells between Rs and M ( Fig. 3 B).

Forewing length ranging 24.1‒26.5 mm, with maximal width from 5.8‒6.5 mm. Hind wing length 20.6 mm with maximal width of 5.3 mm.

Figures

FIGURE 2. Composibittacus reticulatus sp. nov., holotype, CNU-MEC-NN 2014082 p / c, part and counterpart. A. Photograph of part. B. Photograph of counterpart. C. Line drawing of part. D. Pterostigma with five crossveins under alcohol. E. Thorax under alcohol. Scale bars represent 2 mm in A, B, 1 mm in C – E.

FIGURE 3. Composibittacus reticulatus sp. nov., paratype, CNU-MEC-NN 2014083. A. Photograph. B. Line drawing. C. Pterostigma with five crossveins. Scale bars represent 2 mm in A – B, 1 mm in C.