The oldest Calosargus Mostovski, 1997 from the Middle Jurassic of China (Diptera: Brachycera: Archisargidae) Author Zhang, Kuiyan Author Yang, Ding Author Shih, Dong Ren Chungkun text Zootaxa 2007 1645 1 17 journal article 10.5281/zenodo.179727 de333d52-b2e2-47cb-b3de-5c313a86ad12 1175-5326 179727 Calosargus ( Calosargus ) validus Zhang, Yang & Ren , sp. nov. ( Figs. 7–8 , 15–17 ) Diagnosis. Vei n R s 1 short, nearly as long as vein Rs2; vein R2+3 arising slightly proximal of base of cell d; vein R2+3 ending at vein R1 far before wing margin; crossvein r-m nearly located at basal part of cell d; mouth of cell r4 about twice as wide as that of cell r1; mouth of cell m1 nearly as wide as that of cell m2. FIGURE 15. Calosargus ( Calosargus ) validus sp. nov. Holotype. Body with wings photograph in dorsal view. Etymology. The specific name refers to the Latin: validus (vigorous). Holotype . CNU-DB-NN2007010, an almost complete adult body with both wings in dorsal view. Paratype . Part and counterpart CNU-DB-NN2007011, CNU-DB-NN2007012, an almost complete male adult body with both 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 14.5 –17.8 mm ; wing length 8.5 – 8.7 mm , wing width 2.6 mm . Head subround, slightly narrower than thorax. Eyes large, bare; ommatidia visible clearly. Thorax black. Hind femur long and distinctly swollen at apex. Wing hyaline. 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; vein Rs1 arising from middle of wing, nearly as long as 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 10: 6: 7. Crossvein r-m nearly located at basal 1/3 – 2/5 of cell d. Vein M3 absent, vein CuA1 arising from cell d. Vein CuP present. Cell sc wide open, mouth of cell sc about 3 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 wide; base of cell m1 about 1/2 – 2/3 as wide as that of cell m2; mouth of cell m1 nearly as wide as that of cell m2. Mouth of cua1 wide open, about 5 – 6 times as wide as that of cell cup. FIGURES 16–17. Calosargus ( Calosargus ) validus sp. nov. Paratype, photograph. (16) Body with wings in dorsal view; (17) apex of abdomen. Abdomen cylindrical, covered with setulae. Nine segments visible; segment I evidently short. Segments II to VII with distinct stria at side. Segments II to VI with wide black stripe at each end. Remarks. C. ( C. ) validus sp. nov. could be related to C. ( C. ) daohugouensis sp. nov. in the following aspects: vein Rs1 short, nearly as long as vein Rs2, vein R2+3 ending at vein R1 far before wing margin, base of cell m1 about 1/2 as wide as that of cell m2. However, it can be easily separated from the latter by apex of cell r4 about twice as wide as that of cell r1, and apex of cell m1 nearly as wide as that of cell m2. In daohugouensis , the apex of cell r4 is about 4 times as wide as that of cell r1; the apex of cell m1 is narrower than that of cell m2. Meanwhile, C. ( C. ) validus sp. nov. is also similar to C. ( C. ) tenuicellulatus sp. nov. in the robust body, vein Rs1 short, nearly as long as vein Rs2, vein R2+3 arising slightly proximal of base of cell d, vein R2+3 ending at vein R1 far before wing margin, apex of cell r4 about twice as wide as that of cell r1. However, it can be easily separated from the latter by cell d wider, base of cell m2 about 1.5 – 2 times as wide as that of cell m1, and apex of cell m1 nearly as wide as that of cell m2. In tenuicellulatus , crossvein r-m is located at basal 1/3 of cell d; cell d is slender; the base of cell m2 is about 3.5 times as wide as that of cell m1; the apex of cell m1 is slightly wider than that of cell m2.