Strenorhagio conjugovenius, Zhang & Yang & Ren & Shih, 2010, Zhang & Yang & Ren & Shih, 2010

Zhang, Kuiyan, Yang, Ding, Ren, Dong & Shih, Chungkun, 2010, An evolutional special case in the lower Orthorrhapha: some attractive fossil flies from the Middle Jurassic of China (Insecta: Diptera: Brachycera), Zoological Journal of the Linnean Society 158 (3), pp. 563-572 : 569-570

STRENORHAGIO CONJUGOVENIUS ZHANG, YANG & REN GEN. ET SP. NOV. ( FIG. 7 )

Etymology: The specific name refers to the Latin ‘ conjugo ’ (conjoint) and ‘ve nius ’ (vein), because vein R 2+3 and crossvein r–m are coalesced.

Diagnosis: Hind femur swollen at apical part. Crossvein r–m at basal third of cell d, coalesced with vein R 2+3 at vein Rs (with vein Rs 2 having disappeared); mouth of cell sc wide open, about three times as wide as that of cell r 1.

Holotype: CNU-DIB-NN2007022, an almost complete adult body with wings in dorsal view.

Type locality and horizon: Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China; Jiulongshan Formation, the Middle Jurassic (Aalenian–Bajocian).

Description: Body length, 14.0 mm; wing length, 10.5 mm; wing width, 3.7 mm.

Body stout. Head round, slightly narrower than thorax. Eyes large, bare; ommatidia clearly visible, upper facets not distinctly enlarged.

Legs pubescent. Hind femur swollen at apical part, tibia slender. First tarsomere distinctly longer than following tarsomeres.

Wing hyaline; veins thick and strong. Vein Sc ending slightly beyond middle of wing. Veins R 1 and Rs 1 long; vein R 2+3 distinctly and strongly bent upwards at base; vein R 5 ending slightly beyond wing apex. Crossvein r–m at basal third of cell d, and coalesced with vein R 2+3 at vein Rs (with vein Rs 2 disappearing); vein Rs 1 shorter than vein Rs 3. All branches of vein M long, veins M 1 and M 2 bifurcating distal of crossvein m–m, basal trunk of veins M 1 and M 2 slightly shorter than crossvein m–m. Vein CuA 1 arising from cell bm; vein CuP present. Mouth of cell sc wide open, about three times as wide as that of cell r 1; relative length of mouths of cells r 1, r 2+3, and r 4 about 4: 5: 4. Cell bm about as wide as cell br; cell d slender, far from wing margin. Five posterior cells present and wide open; mouths of cell m 1 slightly narrower than that of cell m 2; mouth of cell m 3 narrow, about 2/5 as wide as that of cell cua 1. Cell cup distinctly open; anal lobe small and narrow.

Abdomen cylindrical, robust, and pubescent. Eight segments visible; segment I evidently shortest.

Remarks: Strenorhagio conjugovenius sp. nov. is the fourth species in Strenorhagio gen. nov. It looks very much like S. asymmetricus sp. nov., but there are some unique characters to separate it from the others in the genus: the crossvein r–m and vein R 2+3 are coalesced at vein Rs (with vein Rs 2 disappearing) in both wings; the mouth of cell sc is wide open, and about three times as wide as that of cell r 1.

Figures

Figure 7. Strenorhagio conjugovenius sp. nov. Holotype, body with wings in dorsal view. A, photograph. B, camera lucida drawing.