Trichiosomites obliviosus Brues, 1908

Archibald, S. Bruce & Rasnitsyn, Alexandr P., 2023, Cimbicidae (Hymenoptera, ‘ Symphyta’) in the Paleogene: revision, the new subfamily Cenocimbicinae, and new taxa from the Eocene Okanagan Highlands, Zootaxa 5278 (1), pp. 1-38 : 27-28

Trichiosomites obliviosus Brues, 1908

Figs. 24–25 .

Trichiosomites obliviosus Brues, 1908 p. 260 , Fig. 1 .

Holotype. Holotype MCZ 2036, Brues (1908). A rather complete female with head present, but positioned under thorax (not missing as Brues 1908 presumed).

Diagnosis. As for genus.

Description. Holotype MCZ 2036 ( Fig. 24 ), female. Body: head length 0.5 mm or slightly more, width 0.87 mm; thorax length ca. 2.5 mm; abdomen length ca. 5 mm; body colouration unknown by preservation. Forewing: length ca. 6.0 mm, estimated maximum width ca. 2.0 mm, length/width: ca. 3.0. UCM 4570 ( Fig. 25 ), female. Body: length ca. 9.2 mm; head, antenna dark; thorax dark, wings including pterostigma light; abdomen light. Head difficult to interpret as preserved; moderately transverse, occiput long, three distinct ocelli in low triangle, compound eyes not preserved, sole funicular segment thin, slightly more than half length of club; club expands gradually over three segments (“drop-like”). Thoracic dorsum only partially visible as preserved, median longitudinal mesonotal sulcus and notauli present; mesopleuron with no mesopleural sulcus visible. Forewing: membrane hyaline, length ca. 6.5 mm; maximum width estimated ca. 2.5 mm, length/width: ca. 2.6; pterostigma wide, ca. as cell 2r; R+M shorter than 1-M; maximum length of cell 2r shorter than 3r; 2r-rs longer than Rs between 2r-m, 2r-rs, joining Rs near middle of cell 3rm; 2r-rm straight, short, joins M at 2m-cu; 1-M curved; cell 1mcu with M, 1m-cu sub-parallel; 3r-m straight; cell 2mcu with M slightly longer than 1m-cu; 2m-cu straight; cu-a postfurcal; anal cell separated by 1A fusion with 2A+3A (no crossvein) for length of about a third length of cell 2a. Abdomen: long, wide; ovipositor thick, not exceeding abdomen apex.

Material. Holotype and UCM 4570 , a rather complete specimen missing only the legs and much of the hind wings.

Locality and age. Florissant Formation, Priabonian.

Figures

FIGURE 1. Forewing and hind wing of Corynis crassicornis (Rossi) (Corynidinae) with veins (roman font) and cells (italic font) labelled. Drawn from Vilhelmsen (2019) figure 15B. Scale = 2 mm.

FIGURE 24. Trichiosomites obliviosus Brues holotype, MCZ-2036, Abiinae, from the Florissant Formation:A, photograph; B, drawing; C, drawing of right forewing; D, drawing of left forewing. Scale bars A–B, 5 mm; C–D, 3 mm.

FIGURE 25. Trichiosomites obliviosus Brues, UCM-4570, Abiinae, from the Florissant Formation:A, photograph; B, drawing; C, drawing of right forewing; D, drawing of left forewing. Scale bars A–B, 5 mm; C–D, 3 mm.