Meghyperiella Meunier, 1908

Shamshev, Igor V. & Perkovsky, Evgeny E., 2022, A review of fossil taxa of Microphorinae (Diptera, Dolichopodidae sensu lato), with redescription of the Eocene genus Meghyperiella Meunier, Zootaxa 5150 (3), pp. 411-427 : 413-414

Meghyperiella Meunier

Meghyperiella Meunier, 1908: 112 , pl. 8, figs 5–7. Type species: Meghyperiella porphyropsoides Meunier, 1908 , by monotypy.

Meghyperella: Melander, 1928: 370, error or emendation.

Meghyerellia: Keilbach, 1982: 369, error ( Spahr, 1985: 45).

Included species. Meghyperiella porphyropsoides Meunier, 1908 (Baltic Region, Ukraine (Upper Eocene)).

Remarks. Meunier (1908) established the genus Meghyperiella to include a single species found by him in Baltic amber. He placed this genus to the Hybotinae (now Hybotidae ), which was followed by Melander (1928) in his conspectus of fossil Empididae . Hennig (1971), who examined the types of Meunier’s possible “microphorines”, did not mention Meghyperiella . Ulrich (2004) indicated the correct systematic position of Meghyperiella as belonging to the Microphorinae and even noted its distinguishing features. However, detailed description of the genus remained unavailable.

Diagnosis. Distinguished from other genera assigned to the Microphorinae by the following combination of characters: male eyes holoptic; vein M 2 absent beyond the discal cell, vein closing discal cell (base of M 2 and dm-m crossvein) smoothly undulating.

Redescription. Male. Body length 1.7–1.8 mm, wing length 1.5 mm. Head hemispherical (lateral view). Neck inserted near middle of head. Holoptic, with compound eyes contiguous for entire length of frons; compound eye ovoid in lateral view, occupying most of head, bare, dorsal ommatidia distinctly larger than ventral ommatidia, medial edge of eye with emargination slightly below level of antenna giving rise to demarcation line between larger dorsal and smaller ventral ommatidia. Ocellar triangle distinctly protruded. Gena very narrow. Postgena broad. Antenna inserted near middle of head in profile; stylus arista-like, terminal, 2-articled, basal article short. Palpus digitiform. Proboscis short, narrow, directed anteroventrally; lacinia present; labellum with marginal setae.

Thorax slightly longer than wide in dorsal view; mesoscutum strongly arched, prescutellar depression present; mesoscutellum with posterior margin rounded. Prosternum isolated (precoxal bridge absent). Mesonotal setae welldifferentiated. Mesopleuron bare.

Legs slender, with simple structure and vestiture.

Wing with normally sclerotised veins, covered with uniform microtrichia. Pterostigma present, brownish, elongate oval, occupying about half of costal section between apices of R 1 and R 2+3, and about 2\3 of cell r 1 width. Longitudinal veins complete (except CuA+CuP evanescent). Costa circumambient, running as stronger vein to M 1, much thinner along posterior margin; extreme anterior base with 2 strong setae; short setulae along anterior margin, distinct throughout. Sc distinct apically, reaching costa near middle of wing. Base of Rs originating opposite humeral crossvein. R 1 weakly sinuous, reaching costa far beyond middle of wing. R 2+3 diverging from R 4+5 apically. R 4+5 weakly sinuous. R 4+5 and M 1 parallel apically. Apical section of M 2 absent. Middle section of M 4 nearly as long as its apical section. Short r-m crossvein present in basal portion of wing, distal to base of R 4+5. Crossvein bm-m complete. Cell dm present, emitting two veins (M 1 and M 4), closing vein (base of M 2 and dm-m crossvein) smoothly undulating, cell extended to middle of wing. Cells br, bm and cua in basal fourth of wing. Cells bm and cua broader than cell br. Cell cua closed, rounded apically with CuA curved. CuA+CuP evanescent apically. Anal lobe well-developed and right-angled, alula absent.

Abdomen with tergites 1–6 bearing numerous moderately long, uniform setae, sternites 1–6 with similar sparser setae; sternites 5 and 6 unmodified; structure and vestiture of segments 7–8 unknown.

Terminalia lateroflexed to right; inverted with posterior end directed anteriorly; probably asymmetrical. Hypandrium separated from epandrium; medial hypandrial prolongation absent.

Female. Abdomen subconical, tapered posteriorly, tergites with much shorter setae (number of exposed segments and most part of terminalia unclear); syntergite 9+10 with acanthophorite setae (number and position unclear). Cercus long and narrow, with long setae.

Distribution. Known only from Baltic and Rovno ambers.