Two new fossil species of Itaphlebia (Mecoptera: Nannochoristidae) from Jiulongshan Formation, Inner Mongolia, China Author Liu, Nan Author Zhao, Yunyun Author Ren, Dong text Zootaxa 2010 2420 37 45 journal article 10.5281/zenodo.194461 273cd7a4-269e-4278-ac95-58a213cc027b 1175-5326 194461 Itaphlebia laeta s p. nov. ( Figure 4 A–D, Figure 5 E–F) Material . Holotype female, CNU-MEC-NN2009311-1 and CNU-MEC-NN2009311-2, positive and negative. Paratype , CNU-MEC-NN2009222-1 and CNU-MEC-NN2009222-2, positive and negative. Horizon and locality . Jiulongshan Formation, Middle Jurassic, Daohugou Village, Ningcheng County, Inner Mongolia , China . Diagnosis . Costal area narrow. In forewing, Sc simple, terminating at C near pterostigma; M with 4 branches; Cu1 and M forked before the cross-vein cu1-cu2. Description . Antenna filiform, incompletely preserved. Femur shorter than tibia. Tibial spurs not present. Setae irregularly arranged. Costal area narrow, one cross-vein c-sc between C and Sc. Sc simple, ending at C and extending to pterostigmal area. One short cross-vein sc2-r1 before pterostigma. Rs arised at the same level to cross-vein csc. Rs with 4 branches. Length of R2 two-thirds that of stem of R2+3. Cross-vein r1-r2 at level of pterostigma. Cross-vein r3-r4 at level of cross-vein r1-r2. Cross-vein r5-m1+2 approximately at middle of wing length. Crossvein r5-m1 proximal to cross-vein r4-r5. One cross-vein r4-r5 dividing cell R4 into 2 cells. Conspicuous thyridium at fork of M, which has 4 branches. M3+4 divided beyond the fork of M1+2; cross-vein m1+2-m3 between M1+2 and M3; cross-vein m-cu not straight, slightly S-shaped. Cu1 coalesced with M for a short distance and separated from M before cross-vein cu1-cu2. One cross-vein a1-a2 connected 1A and 2A. 3A absent. Female abdomen with 11 segments, segments 9–11 smaller than segment 8. One pair of cerci located at apex of abdomen. Right cercus with 3 segments. Third segment of left cercus not preserved. Basal segments fused with abdomen segment 11. Body length 7.8 mm , forewing length 8.2 mm , width 2.6 mm . Etymology. From the Latin word laetus (clear), indicating venation is very clearly. Remarks . The new species shows a similarity to Itaphlebia reducta but differs from the latter by location of the fork of R2+3 and length of R2 compared with R2+3.