Calosargus (Calosargus) hani Zhang, Yang & Ren

Zhang, Kuiyan, Yang, Ding & Shih, Dong Ren Chungkun, 2007, The oldest Calosargus Mostovski, 1997 from the Middle Jurassic of China (Diptera: Brachycera: Archisargidae), Zootaxa 1645, pp. 1-17 : 15-16

Calosargus (Calosargus) hani Zhang, Yang & Ren , sp. nov.

( Figs. 18–19 )

Diagnosis. A spurious crossvein present between veins R1 and R2+3; vein Rs1 slightly longer than vein Rs2; vein R2+3 ending at vein R1 far before wing margin; mouth of cell r4 about twice as wide as that of cell r1; base of cell m1 about 1/3 as wide as that of cell m2; mouth of cell m1 slightly narrower than that of cell m2.

Etymology. The specific name refers to collector of this specimen: Mr. Gang Han.

Holotype. CNU-DB-NN2007013, an almost complete adult body with wings in lateral view.

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

Description. Body length 16 mm; wing length about 9 mm, wing width about 2.2 mm.

Head subround, slightly narrower than thorax. Eyes large, bare; ommatidia visible clearly.

Fore and mid legs short and thin; hind femur distinctly long and robust; tibiae slender. Wing hyaline, slen- der. Vein C ending at wing tip; veins C, Sc and R1 markedly thick; vein Sc long, extending far beyond middle of wing. Vein R1 long and robust; a spurious crossvein present between veins R1 and R2+3; vein Rs1 arising from middle of wing, slightly longer than vein Rs2; vein R2+3 arising slightly proximal of base of cell d; vein R2+3 ending at vein R1 far before wing margin; veins R4 and R5 short; vein R5 ending far beyond apex of wing, relative lengths of veins Rs3, R4 and R5 about 7: 3: 4. Crossvein r-m nearly located at basal 1/3 of cell d. Vein M3 absent, vein CuA1 arising from cell d. Vein CuP present. Cell sc wide open, mouth of cell sc about 4 times as wide as that of cell r4, mouth of cell r1 narrow, mouth of cell r4 about twice as wide as that of cell r1. Cell br nearly as large as cell bm. Cell d slender; base of cell m1 about 1/3 as wide as that of cell m2; mouth of cell m1 slightly narrower than that of cell m2. Mouth of cua1 wide open.

Abdomen cylindrical, covered with setulae. Seven segments visible; segment I evidently short.

Remarks. C. (C.) hani sp. nov. is more or less similar to C. (C.) tenuicellulatus sp. nov. However, it can be easily separated from the latter by the distinctly slender wing and cell d, vein Rs1 slightly longer than that of vein Rs2, an excrescent crossvein located between veins R1 and R2+3, and mouth of cell m1 slightly narrower than that of cell m2. In tenuicellulatus , the wing and cell d are wider than in hani ; vein Rs1 is short, nearly as long as vein Rs2; an excrescent crossvein is absent; the mouth of cell m1 is slightly longer than that of cell m2.

Figures

FIGURE 18. Calosargus (Calosargus) hani sp. nov. Body with wings photograph in lateral view.

FIGURE 19. Calosargus (Calosargus) hani sp. nov. Camera lucida drawing, based on the original photograph, in lateral view.