Normyia longistyli, 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 : 25-27

Normyia longistyli , new species

Figures 6A , 9 , 41

DIAGNOSIS: Readily distinguished from other stratiomyids in Burmese amber by the long, thin apical flagellomere (length> than combined lengths of flagellomeres 6 + 7), and by vein M tubular (vs. nebulous) between cells br and bm; other features include 0-1-0 tibial spurs, R 2+3 long, parallel to (vs. converging with) R 1 as in Narcissimyia, but N. longistyli with wing broader and cell d shorter; R 4 +R 4 -R 5 straight (vs. upturned), apex of R 5 ending before wing tip. Terminal abdominal segments of female not telescoping.

DESCRIPTION: Based on female. Body length 3.46 mm; thorax length 1.08 mm; wing length 2.07 mm; abdomen length 1.83 mm. Head: Female only: Large, significantly broader than thorax, slightly compressed dorsoventrally; frons dark, inner margins of eyes widely separated, by distance slightly greater than outside margins of lateral/posterior ocelli; occiput dark, slightly concave, occipital foramen relatively large; occiput dark, with fine setulae only. Face and oral region entirely ventral. Eye: Female: Large, dichoptic, occupying all of lateral surface of head, much of dorsal, frontal, ventral surfaces; facets not differentiated. Eyes completely bare; inner margins bordering frons parallel, very small emargination near antennal bases; inner margins bordering face subparallel; no cheek exposed laterally. Ocelli on raised tubercle, with anterior ocellus directed forward, posterior ocelli directed laterally. Antenna: Projecting forward, with 8 flagellomeres, submoniliform, evenly tapered in width apicad; flagellomere 1 width 6× that of flagellomere 8; apex without stylus but with fine setae; all flagellomeres with sensillar foveae; scape and pedicel funnel shaped, scape shorter, pedicel with apical whorl of setae, length of antenna 0.50 mm; lengths of flagellomeres relative to flagellomere 1: 1.0 (1): 0.30 (2): 0.20 (3): 0.25 (4): 0.36 (5): 0.40 (6): 0.40 (7): 1.10 (8); antennal sockets very close, touching medially. Mouthparts: Labrum not visible, clypeus relatively flat, narrow, bounded laterally by fracturelike sutures; palps light, 2-segmented, apical palpomere clavate, basal one cylindrical. Labellum well developed, fleshy, and membranous, with 18–20 pseudotracheae on each lobe. Thorax: Deep, scutum moderately arched in lateral view. Scutum, scutellum, pleura apparently all dark, but probably iridescent-metallic originally (judging from spectral highlights). Scutum and scutellum evenly, densely, and very finely punctate; each punctation with fine setula; small sparse punctate area on katepisternum. Antepronotum very well developed, but short, without fine, stiff setae; anterior end of antepronotum apparently fitting over collarlike ledge on dorsal margin of occipital foramen. Postpronotum well developed, edges discrete, bordering posterolateral margin of antepronotum; postpronotal lobe small, posterior portion slightly protuberant; anteroparamedian sulci not present on scutum. Transverse suture well developed, deeply impressed, inner apices converging medially; sutures forming pair of low, rounded lobelike portions of scutum posteriorly. Small, narrow, lenticular proscutellum present; scutellum narrow, length approximately equal to width, no spines. Posterior portion of anepisternum slightly protuberant; katepisternum ventrally extended, moderately pendulous, ventral margin ending at middle of mesocoxa; medial margins of katepisterna meeting ventrally. Wing: Relatively broad. Sc complete, long, apex meets C at level of crossvein r-m; C ends slightly past tip of R 5. R and R 1 close and parallel to Sc, first two converging slightly at apex, nearly touching where they meet C. Rs very short, 0.24× length of R 1; R 2+3 is 0.84× length of R 1; fork of R 4 -R 5 long, length of R 4 0.69× that of R 5, base of fork distal to level of cell d apex; R 4 very slightly sinuous, curved primarily at base (not perpendicular to R 5), R 5 virtually straight, tip ending before wing tip. Faint pterostigmatic area very faint; base of vein M between cells br and bm fine but tubular. M 1 very faintly curved; apices of M 1, M 2, CuA 1 tapered and evanescent, barely meeting wing margin; bases of M 1 and M 2 meeting truncate apex of cell d separately. Cell d short, W/L 0.50; cell br longer than bm, both cells narrow. CuA 2 very arched, meeting A 1 well before wing margin. Anal lobe well developed; anal veins, alula not visible. Legs: Robust, covered with fine setulae, tibial spurs 0-1-0; mesotibial spur straight, slightly shorter than width of tibial apex, apical half of spur well sclerotized. Lengths of leg segments: femur> tibia> tarsus, basitarsomere> combined lengths of tarsomeres 2–5. Tarsomere 5 with dorsal apex extended into small lobe; empodium pulvilliform, empodium and pulvilli slender, significantly shorter than pretarsal claws. Abdomen: Anteriorly broad, flattened dorsoventrally. Tergite 1 broadest, tergites evenly tapered in width distad. Tergites 2–6 each with transverse furrow impressed near posterior margins, furrows deepest on tergites 2–5 (faint on tergite 6), furrow lengths ca. 0.9× tergite width; 9 tergites exposed. Female Terminalia: Cercus 2-segmented, segments approximately equal in length; basal cercomere thicker, cylindrical; segments 6–8 probably telescoping, at least moderately.

TYPES: Holotype, male AMNH Bu-SE021.

ETYMOLOGY: From the Latin stilus (noun, a pointed instrument), in reference to the long apical flagellomere.

COMMENTS: The wing venation needed significant reconstruction since both wings are lying immediately over each other and overlapping. The fly was trimmed to 6 × 5 × 3 mm piece, from a cabochen containing an orthopteran hind leg; the amber contains a light suspension of fine particles.

Figures

FIG. 6. Lateral views of thoraces of Burmese amber Stratiomyomorpha. A, B. Stratiomyidae. C, D. Xylomyidae. A. Normyia longistyla, new genus and species. B. Narcissomyia bella, new genus and species. View is slightly ventral. C. Archosolva biceps, holotype (note inflated metacoxa). D. Archosolva sulcata, holotype (note fossa, for apparently receiving the raised mesofemur).

FIG. 9. Normyia longistyli, new genus and species (Stratiomyidae), AMNH Bu-SE021, holotype. A. Wing, reconstructed. B. Antenna. C. Anterior portion of head, ventrofrontal view. D. Female terminalia, ventrolateral view.

FIG. 41. Normyia longistyli, new genus and species (Stratiomyidae), holotype AMNH Bu-SE21. A. Habitus, left lateral view. B. Head, dorsal view. C. Head, ventral view.