Microburmyia analvena Grimaldi & Cumming

Grimaldi, David A., Arillo, Antonio, Cumming, Jeffrey M. & Hauser, Martin, 2011, Brachyceran Diptera (Insecta) in Cretaceous ambers, Part IV, Significant New Orthorrhaphous Taxa, ZooKeys 148, pp. 293-332 : 310-312

Microburmyia analvena Grimaldi & Cumming sp. n. Fig. 7a, b

Diagnosis.

Distinguished from Microburmyia veanalvena sp. n. (below) by longer wing; presence of an anal vein; fringe of fine (vs. thick) setae on posterior wing margin; antennal style very fine, with very small article between it and basal flagellomere.

Description.

A minute fly, body length c. 1.1 mm, thorax length 0.5 mm, wing length 1.15 mm. Head: Short, somewhat flattened anteroposteriad. Cervical region long. Eyes bare, large, well separated; no dorsoventral differentiation of facets; with small, shallow emargination on posterior margin. Proboscis short [palps not visible]. Antenna with basal flagellomere drop-shaped, with sparse setulae; apical style 0.6 × length of basal flagellomere, very thin, with two articles. Three ocelli present. Postocciput expansive, concave. Thorax: Mesoscutum dorsally arched, devoid of setae or setulae; thorax deep in lateral view; mesoscutellum triangular in shape (nearly equilateral), posterior end tilted upward. Coxae of moderate size; legs slender; devoid of setae, tibiae without apical spurs. Pretarsus with large pulvilli; empodium probably setiform. Halter with slender stem, large knob. Wing long, length slightly greater than length of body, wing L/W = 2.72. Costa either without spinules or spinules minute; C reaching slightly beyond apex of R4+5. Posterior margin of wing with fringe of short, fine setae, including alula (setae longer in this area). Vein Sc with apex apparently evanescent, not reaching C. R-R1 nearly straight; R2+3 2.0 × length of R1; R4+5 straight, ends at apex of wing; proximal portion of R4+5 joined to r-m to form distal margin of cell br. Cells br and bm large, br is 0.33x length of wing, W/L cell br = 0.3; cell bm narrower and shorter. Base of M straight, with short apical fork. Crossvein bm-cu slightly shorter than r-m, not in line with each other. CuA1 and CuA2 short, curved slightly toward each other. Vein A1 present, incomplete (reaching to 0.6x distance between vein base and wing margin), apex of vein blunt, not evanescent. Anal lobe and alula small. Abdomen: Short, 1.3 × length of mesothorax, apparently devoid of setae and setulae. Tergites I - V with shallow, median keel; epandrium with pair of large ventral lobes.

Type.

Holotype, male: Myanmar: Kachin (northern Myanmar), in Burmese amber, KU Bu079 (Univ. Kansas, Division of Entomology, Natural History Museum). The amber piece containing the holotype is a very transparent, deep amber color, 14 × 7 × 5 mm, which also contains 2 scelionid wasps. The minute holotype is at the surface of a fractured corner.

Etymology.

in reference to the presence of an anal vein (i.e., the Latin noun vena), albeit incomplete.