Atherhagiox simulans, Grimaldi, 2016

Grimaldi, David A., 2016, Diverse Orthorrhaphan Flies (Insecta: Diptera: Brachycera) In Amber From The Cretaceous Of Myanmar: Brachycera In Cretaceous Amber, Part Vii David A. Grimaldi, Bulletin of the American Museum of Natural History 2016 (408), pp. 1-132 : 38-39

Atherhagiox simulans , new species

Figures 12A, E, F ; 45

DIAGNOSIS: Very similar to A. ambiguum , n. sp., described above, with diagnositic differences as given for that species.

4-5

DESCRIPTION: Based on female. Body length 4.08 mm; thorax length 1.27 mm; abdomen length 2.12 mm; wing length 3.26 mm; proboscis length 0.80 mm. Head: Eyes large, dichoptic, bare, no dorsal-ventral differention. Frons bare, no setae/setulae. Face with bulging clypeus, laterally bordered by deep sulci between clypeus and parafacial plates. Antenna: Aristate. Base membranous; scape slightly longer than pedicel, scape without bristlelike setae; pedicel nearly spherical, with ring of small, stiff setae; basal flagellomere reniform, its attachment to pedicel apparently in center; apical portion of flagellum aristate, length 4× that of longest axis of basal flagellomere, with microscopic pubescence, no minute apical style apparent. Mouthparts: Proboscis length slightly greater than that of head; labellum long, 0.5× length of theca, with fine setae on ventral surface. Labrum long, same length as lacinia + mandible; tip of mandible with several minute teeth/serrations. Palps long, 0.4× length of proboscis, significantly wider at base and tapered to narrow apex, gently curved (dorsally convex); 2-segmented, basal segment 0.3× length of distal segment. Thorax: Scutum dorsally with fine, short, erect setae; longer, thicker setae at middle of scutum, along margins, on disk of scutellum, and in notopleural area. Postpronotal lobe with fine, light setae. No pubescence or setae on pleurites. Wing: Short, broad, W/L 0.42, hyaline except for small pterostigmatic area between distal halves of R 1 and R 2+3. Minute setulae on dorsal surface at base of R-R 1. Vein C with very small, fine spinules to wing tip. Basicosta not observable. Tip of Sc reaches to 0.5× length of wing; R 1 runs very close to Sc, length 0.6× that of wing; R 2+3 sinuous (apparent kink in R 2+3 appears preservational), length ca. 0.7× wing length, apex of R 2+3 not converging with apex of R 1; cells br and bm of nearly equal length; cell d long, narrow, slightly arched; apices of R 4 and R 5 barely encompass wing tip; R 4 branches from stem of R very proximal to apex of cell d (near middle of cell d). Veins M 1, M 2, and M 3 present, first two slightly sinuous. Veins M 3 and CuA 1 parallel; cell cup virtually closed, elongate and narrow, CuP and A 1 nearly meeting at wing margin; vein A 2 present, nearly complete but apically evanescent. Anal lobe well developed; alula shallow, smaller than upper calypter. Legs: Long, slender. Pro- and mesofemur without macrosetae; metafemur with ventral row of very fine setae. Tibial spurs 0-2-1, middle spurs of equal length. All tarsi with ventral row of short, black, spinulelike setae; metatibia with dense dorsal row of spinules. Pretarsal structures small, empodium pulvilliform. Mesocoxa with dense setae; anterior surface of metacoxa not observable. Abdomen (female): Not dorsoventrally flattened, terminal segments tapering and tele- scoping; pleural membrane between tergites and sternites 2–4 broad; tergite 1 obscured (cannot determine if medially divided); tergites 2–4 large, 5–10 appear to be telescoping, significantly narrower than preceding segments. Tergites heavily setulose; sternites light brown, well developed, with fine, sparse setulae. Dorsal portion of tergite 10 obscured (medial division not observable). Cerci 2-segmented, basal segment cordate in lateral view, ventral and dorsal lobes symmetrical; apical cercomere with faint emargination on posterior margin.

TYPE: Holotype, female, JZC Bu-288.

ETYMOLOGY: In reference to the similarity between this species and the type species of the genus.

COMMENTS: The unique specimen is not very well preserved, much of the cuticle of the body crumpled and softened, making sutures and small sclerites difficult to observe (e.g., proscutellum, tergite 1, metaspiracular area). However, the right wing is very well preserved (the left wing is distorted); the proboscis is cleared, distended, and most of the mouthparts are separated (fig. 12A), allowing observation of fine details of these structures.

Figures

FIG. 12. Atherhagiox, new genus (stem-group Tabanomorpha). A, E, F: A. simulans, new species, JZC Bu-288, holotype. B, C, D: A. ambiguum, new species, AMNH Bu-SE2/3, holotype. A. Lateral view of mouthparts, anterior part of head, and antenna. B. Antenna. C. Posteroventral portion of thorax, lateral view. D. Female terminalia, lateral view. E. Female cercus. F. Wing, upper surface.

FIG. 45. Atherhagiox simulans, new genus and species, holotype JZC Bu-288. A. Habitus, left lateral. B. Head, left lateral. C. Right wing. D. Legs.