Penthetria, Meigen, 1803

Skartveit, John & Wedmann, Sonja, 2021, A Revision of fossil Bibionidae (Insecta: Diptera) from the Oligocene of Germany, Zootaxa 4909 (1), pp. 1-77 : 19

Penthetria sp. 2 (figs. 16, 102)

Penthetria ♂ Nr. 2 Statz 1943: 41–42.

Localities: Rott.

Material examined: LACMIP 2533.247ab/LACMIP Type 3377.

The specimen is represented by a single, poorly preserved male specimen from Rott. This specimen is characterized mainly by its small size, with a wing length of only 4.3 mm, but does not exhibit sufficient characters to warrant a formal species description. Its size does, however, distinguish it from all other known fossil Penthetria . The strongly curved R 4+5 could suggest that the species should be placed in genus Hesperinus , however the relatively large head is unlike those usually found in that genus.

Description:

Female unknown.

Male (N=1, figs. 16, 102):

Total length 5.4 mm, specimen entirely brown (probably not original colour)

Head: Length 0.76 mm, width 0.76 mm. No details discernible, antennae and palpuss not preserved.

Thorax: Length 1.3 mm, dorsally relatively flat. Scutellum small, not prominent. Haltere brown. Pile not preserved.

Wing (fig. 102): Length 4.3 mm, width 1.7 mm, length/width = 2.6. Light brownish (possibly hyaline in life), veins brown, distinctive, radial veins strong, posterior veins much finer. Humeral ven present, vertical. Subcosta straight, distinctive. Pterostigma oval, brown, distinctive. R 2+3 rather long, almost straight. R 4+5 apically rather strongly curved. Crossvein R-M slightly oblique. Vein measurements are given in Table 3.

Legs: Brown, slender, relatively short. Fore tibia 1.1 mm long, 0.11 mm wide.

Abdomen: cylindrical, 3.8 mm long, 0.8 mm wide. Pile not preserved.

Terminalia: Poorly preserved. Gonostylus apparently relatively slender.