Exilibittacus, 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 : 787-790

Genus Exilibittacus n. gen.

TYPE SPECIES. — Exilibittacus lii n. sp.

ETYMOLOGY. — The generic name is derived from the Latin word “ exil -” (weak) and bittacus (a recent genus of Bittacidae ). Gender masculine.

DIAGNOSIS. — One crossvein between ScP and RA; RA sharply bent distally; RP+MA forking before the fork of MP; “Kreuz der Bittaciden” aligned, MP3+MP4+CuA1+2 forking before posterior part of “Kreuz der Bittaciden” (if existing); one crossvein between MP4+CuA1+2 and CuA3+4; AA3+4 short; Forewing both RP+MA and MP with four branches, but hind wing, three branches.

REMARKS

Exilibittacus n. gen. can be assigned to the infraorder Raptipeda ( Willmann 1977, 1989) on the characteristics of legs: long and slender, with a single, predatory claw, the fifth tarsomere folding back toward fourth. Furthermore, it can be classified into the Bittacidae by AA3+4 short and AP1+2 absent on a well-preserved forewing, in contrast to cimbrophlebiids with AA3+4 long and AP1+2 very long and branched.

Forewing of Exilibittacus n. gen. is similar to Antiquanabittacus Petrulevičius & Jarzembowski, 2004 and Mongolbittacus Petrulevičius, Huang & Ren, 2007 in the wing venation and size. But the new genus can be distinguished from Antiquanabittacus by these characters: MP3+MP4+CuA1+2 not short; no crossvein present between AA3+4 and CuP; only one crossvein between MP4+CuA1+2 and CuA3+4. It can also be differentiated from Mongolbittacus by one crossvein between ScP and RA; RA with one pterostigma crossvein to RP1 and RP+MA forking before the fork of MP. This new genus can be easily distinguished from all other fossil genera: hind wing both RP+MA and MP are with three branches; one crossvein between ScP and RA; RA with one pterostigma crossvein to RP1; RP+MA forking before the fork of MP; “Kreuz der Bittaciden” aligned, MP3+MP4+CuA1+2 forking before posterior part of “Kreuz der Bittaciden” (if existing); one crossvein between MP4+CuA1+2 and CuA3+4; and AA3+4 short.

The new genus Exilibittacus n. gen. has both RP+MA and MP with four branches in forewings,

FIG 1. — Exilibittacus lii n. gen., n. sp., holotype: A, part (CNU-M-NN2010001p); B, counterpart (CNU-M-NN2010001c).

while both with three branches in hind wing; RP1+2 and MP3 not forking. Up to date, among the described bittacids, only Orobittacus has vein RP+MA with three branches (RP1+2 not forking). This is the first time that the character of MP with three branches in hind wings is reported for the Bittacidae .