Exilibittacus lii, Yang & Ren & Shih, 2012

Yang, Xiaoguang, Ren, Dong & Shih, Chungkun, 2012, New fossil hangingflies (Mecoptera, Raptipeda, Bittacidae) from the Middle Jurassic to Early Cretaceous of Northeastern China, Geodiversitas 34 (4), pp. 785-799 : 790

Exilibittacus lii n. gen., n. sp. (Figs 1A, B; 2A-F)

HOLOTYPE. — CNU-M-NN2010001p/c, part and counterpart, lateral view, preserved completely, except for missing right hind wing and partial left middle leg. Deposited at the Key Laboratory of Insect Evolution & Environmental Changes, the College of Life Sciences, Capital Normal University ( CNU), Beijing, China.

ETYMOLOGY. — The specific name is dedicated to Mr. Junyan Li who kindly donated this important specimen to CNU from his private collection.

HORIZON AND LOCALITY. — Jiulongshan Formation, Middle Jurassic, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China.

DIAGNOSIS. — As for the genus by monotypy.

DESCRIPTION

Female, small sized.

Head

Vertex of head raised, rostrum long and slender; eyes large; antenna filiform, with short scape, stout pedicel (Figs 1A, B; 2A).

Leg

Long and slender densely covered by short setae; femur strong, tibia with two terminal spurs; tarsus with five segments, the fifth tarsomere folded against the fourth, with a single, predatory tarsal claw. (Figs 1A, B; 2A, B).

Forewing

Without thyridium, basal part narrow, gradually broaden to apex; pterostigma slightly dark; ScP short, ending in the middle of forewing; one crossvein arising at 2/3 of ScP between ScP and RA; RA through pterostigma, slightly bent distally, not branched; both RP+MA and MP four branches; RP+MA forking before the fork of MP, almost at 1/3 of wing length; MP1+2 forking after RP3+4+MA; RA with two crossveins to RP1+2 and RP1 (one crossvein is pterostigma crossvein); one crossvein between MP1 and MP2; one crossvein between MP2 and MP3; no crossvein present between AA3+4 and CuP; AA3+4 short; AP1+2 absent. Right forewing one crossvein between RP2 and RP3+4; one crossvein between RP3+4 and MA; two crossveins between MA and MP1, but these four crossveins absent in left forewing. Left forewing part of “Kreuz der Bittaciden” (mp1+2-mp3 crossvein) preserved. (Figs 1A, B; 2A, C, D).

Hind wing

Slightly narrower than forewing, apical margin slightly sharp-pointed; one crossvein arising before the end of ScP between ScP and RA; both RP+MA and MP with three branches; MP1+2 forking after RP3+4+MA; RA with two crossveins to RP1 (one crossvein is pterostigma crossvein); one crossvein between RP1+2 and RP3+4; one crossvein between RP3+4 and MA; one crossvein between MA and MP1; one crossvein between MP1 and MP2; one crossvein between MP2 and MP3; one crossvein between CuA and CuP; AA3+4 very short, reaching posterior wing margin after the origin of RP; AP1+2 absent. (Figs 1A, B; 2A, E).

Abdomen

Eight segments visible, T9 fused with T8; terminal abdominal segments well preserved; subgenitalis (bearing a conspicuous patch of large setae), tergum octavum, supra-anale, cercus and subanale visible. (Figs 1A, B; 2A, F).

Measurement

Body 12mm long; forewing 7.5 mm long, 2.2 mm wide; hind wing 7.0 mm long, 1.7 mm wide.