Mongolbittacus speciosus, Liu, Sulin, Shih, Chungkun & Ren, Dong, 2014

Liu, Sulin, Shih, Chungkun & Ren, Dong, 2014, Four new species of hangingflies (Insecta, Mecoptera, Bittacidae) from the Middle Jurassic of northeastern China, ZooKeys 466, pp. 77-94 : 79-81

Taxon classification Animalia Mecoptera Bittacidae

Mongolbittacus speciosus sp. n. Figs 1, 2, 3, 4

Etymology.

The specific epithet is derived from a Latin word of speciosus (showy), highlighting the well-preserved wings in the holotype.

Holotype.

A male specimen well-preserved, CNU-MEC-NN2013008 P/C, part and counterpart. Body 8.8 mm long; forewing 11.3 mm long with a maximal width of 3.0 mm; hind wing 9.1 mm long with a maximal width of 3.0 mm.

Horizon and locality.

Jiulongshan Formation, late Middle Jurassic, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China.

Diagnosis.

In forewing, Sc reaching the anterior margin proximad of the forking of Rs; one crossvein between C and R1; 1A and 2A fusing at base; and 2A sharply curving to the posterior margin.

Description.

A male specimen in lateral view. The head oviform with robust and slender chewing mouthparts. Compound eyes large and oval. Antennae almost complete, filiform, about 6.9 mm long, comprising about twenty antennomeres; the lengths of basal antennomeres almost the same, but several apical antennomeres shorter than the basal ones. Thorax divided into pronotum, mesonotum and metanotum from the lateral view (Figs 1 A–C, 4B, F).

Legs. Long and slender in lateral view, densely covered with short setae. But all legs fragmented due to poor preservation. Mesocoxa, metacoxa, trochanter visible in lateral view. Mid tibia 4.4 mm; tibial spurs long and sharp. Tarsus with 5 tarsomeres and a single pretarsal claw, but the fifth tarsomere not folded against the fourth as preserved. In addition, the second and third tarsomeres covered with a few small spines (Fig. 1 A–D).

Forewing. No maculation, base of wing narrow. Sc short, one oblique subcostal crossvein (Scv) between Sc and R1; one crossvein between R1 and C; R1 smooth and reaching the dark pterostigmal area; Rs originating from R1 at an acute angle; one crossvein between R1 and R2+3, one crossvein between R2+3 and R4 and one crossvein between R4 and R5; the 'bittacid cross’ not aligned, Z-shaped (in side view), and posterior part of 'the 'bittacid cross’ distad of the forking of M3+4; M with four branches and bifurcating proximad of the forking of Rs; one crossvein between R5 and M1, one between M1 and M2 and one between M2 and M3; M4 simple, one long and oblique crossvein between M4 and Cu1; Cu1 and M overlapping at base for a short distance; Cu2 curving sharply with a 90° angle, reaching the posterior margin; Cu1 and Cu2 almost parallel, with three crossveins between them, the first oblique crossvein located at the base of the wing, the second at the level of Scv, and the third near the sharp bending of Cu2. Veins 1A and 2A fusing at base, 1A reaching the posterior margin proximad of the origination of Rs from R1; two crossveins between 1A and Cu2 (Figs 2 A–D, 3A).

Hind wing. Sc short, reaching the anterior margin proximad of the forking of Rs; one crossvein between R1 and C; One subcostal crossvein (Scv) between Sc and R1, one crossvein between R1 and R2+3, and one short crossvein between R2+3 and R4; R4 sharply bending upwards, then parallel with R5, one crossvein between them; the 'bittacid cross’ not aligned, Z-shaped; M forking proximad of the bifurcation of Rs; one crossvein between R5 and M1, one between M1 and M2, one between M2 and M3 and one oblique crossvein between M4 and Cu1; Cu1 and Cu2 almost parallel with two crossveins between them; Cu2 bending sharply with an 90° angle at the level slightly proximad of the forking of M3+4; one crossvein between Cu2 and 1A (Figs 2 E–H, 3B).

Abdomen. Abdomen 6.5 mm long, with 9 visible segments. The ninth tergum (T9) connecting gonocoxite with dense short setae at the apex, epiandrium well-preserved with long setae on the surface; procitiger and cercus present in lateral view (Figs 1 A–C, 4A, C).

Remarks.

Mongolbittacus speciosus sp. n. (Figs 1-4) is assigned to the genus Mongolbittacus based on the following generic diagnostic characters: R4+5 plus R4 distinctively curved; M4 simple; the 'bittacid cross’ not aligned; wide posterior anal field; and the forking of M proximad of the Rs forking. Mongolbittacus speciosus sp. n. is distinguished from the other two species of Mongolbittacus by veins of 1A and 2A fusing at base, and 2A sharply curving to the posterior margin, as shown in the key below.