Palaepangonius glossa, 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 : 33-35

Palaepangonius glossa , new species

Figures 11A , 43

DIAGNOSIS: Wing long and narrow, W/L 0.30, similar to P. sellwoodi (Mostovski et al.) . Costa just distal to basicosta thickened (as in Tabanidae ): R 2+3 short, ending very near apex of R 1 but not meeting it; R 4+5 nearly linear (not sinuous), close and parallel to Sc (as in P. sellwoodi ); basal cells like those of P. gordoni (fig. 11). Differs from P. eupterus by the longer cell br, and by vein R 4 not sinuous and diverging from stem more acutely.

DESCRIPTION: Based on female. Body length 4.83 mm; thorax length 1.34 mm; abdomen length 2.93 mm; wing length 4.49 mm; proboscis length 1.67 mm. Head: Eyes large, dichoptic, in dorsal and lateral view with occiput visible posteriorly. No differentiation of facets. Eye bare, inner margins slightly divergent from vertex to antennae, virtually parallel. Frons essentially bare, with minute and very sparse setulae. Frons, ocellar tubercle, occiput black. Ocelli on low tubercle, with short, stiff setae. Occiput with short, stiff, scattered setae. Frontal region of head obscured by clumps of dense fungal mycelia. Postgena with some long, fine erect, light setae. Antenna: On low tubercle; scape small, ringlike; pedicel cylindrical; basal flagellomere subcircular, not reniform. Distal portion of antennal flagellum aristate, with fine pubescence; fine setalike stylus present. Mouthparts: Proboscis long, ca. 1.9× length of head, labellum long and slender, 0.37× length of entire proboscis. Palp 0.25× length of proboscis; slender (shape obscured); palps in frontal view converging, with tips meeting medially over proboscis. Mandibles-laciniaelabrum enfolded within labium (not visible). Thorax: Coated in milky layer, but most details visible. Dorsum appears dark through milkiness, with short, sparse, erect setae. Notopleural area with slightly thicker, stiff, short setae. Anepimeron and katepisternum with short, erect setae; other pleurites bare. Area around metathoracic spiracle and above metacoxa is obscured. Scutellum with fine, short setae on disk; longer ones on margin. Proscutellum appears to be present. Wing: Narrow and long, W/L 0.30. Sc long, 0.5× length of wing; R 1 slightly longer, with thickened apex; R 2+3 slightly upturned, converging toward but not meeting apex of R 1. Fork of R 4-5 at same level as apex of cell d; tips of R 4 and R 5 straddling apex of wing, but veins only moderately divergent. Cell d narrow, slightly curved; veins M 1, M 2, M 3 present, first two slightly sinuous. Veins M 3 and CuA 1 slightly convergent. Cell br longer than cell bm. Cell cup open, veins CuP and A 1 not meeting. Legs: Long and slender. Tibial spurs 1-?-2, spurs long, lengths 1.5× (pro) to 2.0× (metathoracic) the apical width of respective tibia. Femora with no macrosetae or with very few, fine ones. Tibiae and tarsi setulose, without rows of short, black spinulelike setae on dorsal or ventral margins. Protarsi obscured. Hind coxa with anterior surface obscured. Abdomen: Partially preserved, segmentation obscured. Tergite 1 not visible. Sternites well developed. Female cerci 2-segmented, basal segment mostly obscured, apical segment cordate.

TYPE (S): Holotype, female, JZC Bu-248.

ETYMOLOGY: Directly from the Greek, glossa (“tongue”), treated as a feminine noun in apposition

COMMENTS: Unfortunately, critical areas of the thorax are obscured in the fossil, i.e., the metathoracic pleural area and tergite one (i.e, medially divided or not). The fly occurred in an ovoid cabochen originally 33 × 15 × 12 mm, lying at one end, and then separated. A flat surface was polished over the thorax and head plus wing. There are internal flows within the piece, with a suspension of particulate debris, trichomes, sand grains, and a beaded lacewing ( Neuroptera : Berothidae ).

Figures

FIG. 11. Wings of assorted genera of Cretaceous Tabanomorpha. A. Palaepangonius glossa, new species, JZC Bu-248. B. Athericites kensmithi (ex: Mostovski et al., 2003). C. Sinocretomyia miniscule (ex: J.-F. Zhang, 2012). D. Galloatherix incompletus (ex: Nel et al., 2014). Not to the same scale.

FIG. 43. Palaepangonius glossa, new species (stem-group Tabanomorpha), holotype JZC Bu-248. A. Habitus, right lateral. B. Head, dorsal view.