Bibio dislocatus Théobald, 1937

Skartveit, John & Nel, André, 2017, Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits, Zootaxa 4225 (1), pp. 1-83 : 66-67

Bibio dislocatus Théobald, 1937

(Figs. 62 – 64, 184 – 187)

Bibio dislocatus Théobald, 1937: 224 – 225.

Bibio consolida Théobald, 1937: 225 . Syn.n. Plecia macroventris Théobald, 1937: 229 . Syn.n.

Material examined. Holotype (female) of Bibio dislocatus NMB F1378. Holotype (female) of Bibio consolida NMB F1379. Holotype (female) of Plecia macroventris NMB F1383.

Additional material (3 females) NMB F1385/1-2, F1386/1-2.

Localities. Kleinkembs.

Diagnosis. A medium-sized (8.0 – 9.0 mm), robust Bibio . Antennal flagellum possibly 7-segmented. Fore tibia with spur about half as long as anterior spine. Wing hyaline, veins pale, pterostigma indistinct, crossvein R-M about as long as basal section of Rs.

Redescription. Male unknown.

Female (fig. 185): Total length 8.0 – 9.0 mm (N=3), robust. Entirely black.

Head (fig. 186): Length 0.95 – 1.03 mm (N=4), width 1.06 mm (N=1). Black, widest behind middle, considerably narrowing forwards. Ocellar tubercle indistinct. Antenna rather small, flagellum possibly 7- segmented, 0.63 mm long (N=1).

Thorax: Length 2.4 – 2.6 mm (N=4). Black, relatively flat dorsally.

Wing (fig. 184): Length 5.9 – 7.5 mm (N=2). Hyaline, R-veins light brown, posterior veins colourless. Pterostigma pale brown, scarcely visible. Costa extends slightly beyond apex of R4+5. Basal section of R s subequal to crossvein R-M.

Legs: Brown to black, most likely all black in life. Fore tibia with spur a little over half as long as spine. Femorae strongly clavate, hind tibia and all tarsi slender. Fore femur 1.6 – 1.7 mm long (N=3), 0.58 – 0.71 mm wide (N=3), fore tibia 1.6 – 1.7 mm long (N=3), hind femur 2.1 – 2.3 mm long (N=4), 0.32 – 0.38 mm wide (N=4), hind first tarsomere 0.66 – 0.77 mm long (N=4), 0.25 mm wide (N=1).

Abdomen: Length 5.6 – 6.2 mm (N=3). Brown, most likely black in life, cylindrical, rather stout.

Terminalia (fig. 187): Cerci small and rounded.