Lindneromyia dominicana, Grimaldi, 2018

Grimaldi, David A., 2018, Basal Cyclorrhapha In Amber From The Cretaceous And Tertiary (Insecta: Diptera), And Their Relationships: Brachycera In Cretaceous Amber Part Ix David A. Grimaldi, Bulletin of the American Museum of Natural History 2018 (423), pp. 1-97 : 1-97

Lindneromyia dominicana , new species

Figures 10 , 35

DIAGNOSIS: (male only). Distinguished from the other species in Dominican amber, L. neomedialis , by 2 uniserial rows of dcs (vs. only 1 pair [prescutellar] dcs); 2 pairs of scutellars (vs. 1 pair); tergite 6 with 3 pairs of stiff, spinelike setae on posterior margin (vs. none); metatarsomeres 1, 2 with seta adjacent to lateral seam of bifid scales (vs. no setae); M forked; crossvein dm-cu ~1.3× its length from wing margin (vs.>3).

DESCRIPTION: (male only). Head: Width greater than thorax. Eye very large, holoptic for ~15 facets, bare, dorsal facets 2× diameter of ventral ones; frontal margins emarginate around bases of antennae. (Silvery layer of air covers most surfaces of eyes, portions near some margins not being covered, giving appearance of emarginations on posterior and dorsal margins, but entirely an artifact). Frons mostly not observable; small triangle exposed above antennae. Ocelli on low tubercle, setae not observable. Occiput with well-developed setae; gena and postgena bare. Antenna: Entirely black like face, possibly velvety; basal 3 segments small, basal flagellomere roughly ovoid, with narrow tip (no slender extension); 3 aristomeres, basal 3 minute, apical aristomere long, thin, completely bare. Mouthparts short, almost entirely recessed into oral cavity (details not observable).

Thorax: Scutum rounded but not arched; scutum and scutellum appear black (possibly velvety). Acrostichals absent. Dorsocentrals in 2 uniserial rows ~10 dcs each; prescutellar longest dc, twice length of adjacent dc; remaining dcs very small. No supraalar setae, 3 notopleurals; 1 postalar. Scutellum with 2 pairs marginal setae; apical pair twice the length of anterior pair; both pairs upright. Wing: Fairly short and broad, length/width 0.50. Membrane mostly bare, portions of posterior and apical margins with very fine, faint microtrichia; costal cells entirely bare. Prehumeral C seta very near wing base. Vein C ends at apex of M 1; with fine spinules, ending at apex R 2+3. Sc, R 1 close and parallel in basal half, membrane between them tinted; pterostigma absent; Sc ~0.45× wing length, R 1 0.70× wing length. R 2+3 terminates just before wing tip; R 4+5 at wing tip. M branched, asymmetrical, M 1 twice the length of M 2. Crossvein br-m at level of 0.65× Sc length; dm-cu 1.3× its length from wing margin, cell dm long. Vein CuP very slightly curved; A 1 not observable; cell cup relatively short, slightly longer than apical vein. Anal lobe well developed; alula not observable. Legs: Femora without macrosetae, spines, or tubercles. Tibiae: Long ventral row/seam bifid scales present, shorter dorsal row; presence/absence mesotibial spurs not observable; apex of mesotibia and much of metatarsomeres with thick, dark setae (lengths almost equal to tarsal width). Tarsi: pro- and mesotarus with biserial ventral rows of bifid scales (mesal row thickest); metatarsomeres 1–4 laterally flattened, expanded, widths 1> 2> 3> 4> 5; lengths 3> 1> 2> = 4> 5.

Abdomen: Slightly longer than thorax, wings extended well beyond apex of abdomen. Six large tergites dorsally, 3 small tergites tucked ventrally (tergites 7 and 8 very short); epandrium (tergite 9) about same length as tergite 6. Tergites 1 and 2 with numerous long, fine setae laterally; middle portions of tergites 1 and 2 and others with very sparse, short setulae. Tergite 6 with 3–4 stiff, long, thick setae on posterior margin. Sternites: Only 3 large ones visible. Male terminalia: Epandrium with a few, very small scattered setulae, U-shaped in posterior view; surstylus well developed, triangular, articulates with (but not connected to) epandrium. Cerci ovoid, setulose. Other details not visible.

SPECIMEN EXAMINED: Holotype, Male, AMNH DR-14-736 , in amber from the Dominican Republic (Early Miocene). The fly is entirely preserved, but a layer of bubbles in the amber on the right side is very close to the specimen; left lateral and dorsal views are best observed. Portions of eyes have a silvery layer of air. The fly may have been velvety black, as it reflects very little light. The amber piece was embedded in synthetic resin and trimmed close to the fly for optimal observation.

ETYMOLOGY: Referring to the Dominican Republic, the country of origin.

Figures

FIG. 10. Lindneromyia dominicana, n. sp. (Platypezidae), male holotype in Dominican amber, AMNH 14-736. A. Left lateral habitus. B. Frontal view of head. C. Lateral view of head. The eyes are largely covered with a layer of air, except for dark areas that appear, deceptively, to be emarginations.

FIG. 35. Lindneromyia dominicana, n. sp. (Platypezidae), male holotype in Dominican amber, AMNH 14-736. A. Wing. B. Apex of abdomen, left lateral. C. Protarsomeres 1–4. D. Metatarsomeres 1–3, lateral.