Platypezidae

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

Platypezidae , genus and species undetermined

Figure 36

SUMMARY: Partial male specimen in Lebanese amber, missing most of head, some of thorax, all of legs and abdomen; wing entirely preserved. Eye with dorsoventral differentiation of facets; thorax with at least 2 pairs prescutellar dorsocentrals (presence/absence acrostichals and serial dorsocentrals not observable); wing with Sc very long, R 4+5 terminating at apex of wing; M forked, slightly asymmetrical; dm-cu distant from wing margin by 4× its length; cell cup short, acute, length slightly less than length of apical vein. Microtrichia not observable.

DESCRIPTION: (male only). Head: Eye with facets dorsoventrally differentiated (dorsal ones larger); dorsal margins lost, not observable. Occiput apparently bare. Antenna: Scape bare and pedicel lost, flagellum detached but close to body; basal flagellomere roughly triangular, with deep medial emargination; arista terminal, basal two aristomeres (flagellomeres 2 and 3) small, tubular; apical aristomere fine, longer, entirely bare. Thorax: much of it lost at surface and in amber. Acrostichals not observable; 2 pairs prescutellar dorsocentrals present, presence/absence of serial dorsocentrals not observable. Supraalar, postalar, notopleural setae not observable; 1 (pair?) scutellar setae preserved; prescutellum absent. Wing: Relatively short, broad, length/ width 1.9. Tinting between Sc and R 1 not observable; pterostigma absent. Termination of vein C not observable (wing tip and posterior edge lost at surface of amber), C with spinules. Vein Sc long, 0.55× length of wing; R 1 close and parallel to Sc, diverging at apex; R 4+5 ending at wing tip. Crossvein r-m short, at level of middle of Sc. M forked, slightly asymmetrical, length M 1 slightly greater than stem of M (from dm-cu). Cells rm and bm complete. Crossvein dm-cu relatively short, distant from apparent margin of wing by ~4× its length. Cell cup slender, acute, slightly shorter than apical vein; CuA 2 straight, not curved; anal lobe large (folded in specimen), alula well developed.

SPECIMENS EXAMINED: AMNH JG79/76, in Acra Collection of Lebanese amber (Early Cretaceous) at the American Museum of Natural History.

COMMENTS: The specimen is one of only two Platypezidae known from Early Cretaceous amber of Lebanon, making these among the oldest Platypezidae . The specimen is not formally named here because the only significant diagnostic characters involve the wing venation. Most of the head, much of the thorax, all legs and the entire abdomen are lost. Absence of data on acrostichals, dorsocentrals, and leg characters (e.g., bifid scales, metatarsomeres) results in too much uncertainty regarding placement. Distinctive features of the wing venation are the very long Sc vein and dm-cu distant from the apparent margin of the wing.

Figures

FIG. 36. Platypezidae indet., male in Early Cretaceous amber from Lebanon, AMNH JG 79/76. A. Entire body, as preserved, showing exposed internal structure of head. B. Detached antenna, as preserved.