Trifionyx Lepeco & Melo, 2022

Lepeco, Anderson, Barbosa, Diego N. & Melo, Gabriel A. R., 2022, A remarkable new family of stinging wasps from the Cretaceous of Myanmar and China (Hymenoptera, Aculeata), Journal of Hymenoptera Research 94, pp. 163-190 : 163

† Trifionyx Lepeco & Melo gen. nov.

Type species.

† Trifionyx pilosus Lepeco & Melo, sp. nov.

Diagnosis.

The single species allocated in this genus is differentiated from † Mirabythus and † Trifionyximus gen. nov. by the absence of cells enclosed by tubular veins in the forewing (Fig. 5F ) and the enlarged head, which is far wider than mesosoma. From † Prionaspidion gen. nov. it can be differentiated by the trifid tarsal claws (Fig. 5G ); tibial spur formula 1-2-2; dorsal surface of propodeum with a transverse depression between spiracles (which may correspond to the metapostnotum); ocellar triangle below upper eye level and convex clypeus disc. † Trifionyx gen. nov. is unique within † Trifionychidae fam. nov. in having the body with conspicuously developed pubescence, including on the compound eyes.

Description.

Head. Enlarged, far wider than mesosoma; prognathous. Entire apical margin of clypeus with small denticles; disc of clypeus relatively large, convex. Frons wider than twice eye length, flat. Frontal line not indicated. Compound eye relatively small, bulging, covered with erect setae. Vertex arcuate in frontal view; extending behind lateral ocelli for at least 1.5 times length of ocellar triangle. Mid ocellus far below upper tangent of compound eye. Lower margin of lateral ocelli below upper eye tangent. Antenna. F1 3 times as long as maximum width, longer than F2; F2-F8 about twice as long as maximum width. Mesosoma. Pronotal collar relatively short, as long as half-length of mesoscutum; anterior surface of pronotum somewhat rounded in dorsal view, with transverse sulcus at mid-height; surface near posterior edge with transverse depression. Surface of mesoscutum between notauli slightly convex, level with lateral surfaces. Mesepisternum with a shalow transverse sulcus above mesepisternal pit. Metanotum with few short carinae on sublateral surfaces. Propodeum without box-like aspect, posterior slope convex; dorsal surface depressed transversally between spiracles. Legs. Arolia not enlarged. Forewing. Veins C and Sc+R completely fused. Pterostigma present. Marginal cell absent. Submarginal cell not enclosed by tubular veins. Radial, first cubital, and medial cells defined by nebulous veins. Vein M+Cu nebulous. Vein cu-a nebulous. Distal portion of vein Cu nebulous. Vein A spectral. Hindwing. Vein C present, nebulous. Vein A absent. Metasoma. Apparently short, shorter than mesosoma; segments apparently not telescoped within one another.

Etymology.

The name is derived from Latin and results from the combination of trifidus, meaning "cleft into three", and onyx, meaning “claw”. The name is masculine.

Figures

Figure 5. † Trifionyx pilosus sp. nov. Holotype female (DZUP Bur- 1906) A dorsal view of head and mesosoma B dorsal view of mesosoma C ventral view of head D ventral view of mesosoma, habitus, ventral view E wings F detail of mesotarsal claw. Scale bars: 0.5 mm.