Vosegus triassicus, Szwedo & Nel, 2011

Szwedo, Jacek & Nel, André, 2011, The oldest aphid insect from the Middle Triassic of the Vosges, France, Acta Palaeontologica Polonica 56 (4), pp. 757-766 : 758

Vosegus triassicus sp. nov.

Fig. 1

Etymology: specific epithet derived from the Triassic period.

Type locality: Arzviller, department Moselle, Vosges, France.

Type stratum: Lower Anisian (“Upper Buntsandstein”), early Middle Triassic “Grès à Voltzia ” Formation ( Gall and Grauvogel−Stamm 2005).

Holotype: only single specimen known, forewing: EOST No. 5916 (part), 5917 (counterpart), Louis Grauvogel Collection , housed in EOST, Strasbourg, France.

Diagnosis.—As for genus.

Description.— Holotype forewing over 2.3 mm long (base and apex weakly preserved), and about 0.8 mm wide (length/ width proportion may be slightly affected by distortion caused by preservation in matrix). Costal margin distinct, but not thickened. Costal cell slightly narrower than radial cell. Stem Sc+R+(M)+CuA very thick at base, straight, slightly curved at level of CuA stem separation; Sc forms deep furrow along R+M, weakened basad of CuA stem. Sc+RA 1 separated at level of M stem forking, forming basal border of stigma; RA 2 (R 1 in interpretation of Shcherbakov 2007) slightly arcuate, delimiting posterior margin of stigma; RP ~ 0.9 mm long from base to apex; RP separated well basad of stigma base, arcuate, reaching wing margin basad of apex. M stem 0.35 mm from base to apex, with sclerotised part 0.22 mm long; its base, if prolonged to stem, reaching it at shorter distance than CuA stem. M forked at level of pterostigma base; M 1+2 about 0.5 mm long, distinctly shorter than terminal M 2, terminals M 1 and M 2 subequal in length (both ~ 0.3–0.5 mm), terminal M 3+4 0.66 mm long, slightly curved in apical portion. CuA stem 0.25 mm long, diverging at 50°, short, length roughly same as the distance between common stem and first forking of M stem, and shorter than terminal CuA 2 length; terminal CuA 1 about twice as long as terminal CuA 2 (0.75–0.8 mm and 0.3–0.4 mm long respectively). Claval furrow and Pcu+A 1 not preserved. Nodal flexion line not visible (if present).

Veins and pterostigma darkened (more sclerotised?), membrane unicoloured, probably hyaline.

Figures

Fig. 1. Forewing of the early Middle Triassic (early Anisian) aphid Vosegus triassicus gen. et sp. nov. A. Reconstruction. B. Venation scheme. C. Part (No. 5916). D. Counterpart (No. 5917).