Grandixyela Zheng, 2021

Zheng, Yan, Kopylov, Dmitry S., Zhang, Qi, Zhang, Hai-Guang, Qin, Min, Chen, Jun & Zhang, Hai-Chun, 2021, Discovery of a new symphytan wasp in the mid-Cretaceous Kachin amber (Hymenoptera, Syspastoxyelidae), Palaeoentomology 4 (6), pp. 629-636 : 630

Genus Grandixyela Zheng , gen. nov.

Type species. Grandixyela rasnitsyni Zheng , sp. nov.

Etymology. The generic name derives from the Latin “grandis” meaning large and the generic name Xyela . The gender is feminine.

Diagnosis. Head large and broad. Antennal thread (remaining portion of flagellum, that is, flagellomeres 2–13) 12-segmented and distinctly longer than first flagellomere. Pronotum distinctly shorter than wide. Pterostigma narrow (3.6× as long as wide), completely sclerotized.2r-rs positioned near midlength of pterostigma. 1-RS elongate (not dot-like), much shorter than 1-M. RS distal of 2r-rs gently curved S-like, reaching wing margin scarcely beyond pterostigma. RS+M arched. Cell 1mcu slightly longer than wide, nearly pentagon-shaped. Crossvein 2m-cu gently bent, r-m and 2cu-a meeting at distinct angle. Fore tibia with a row of thick setae at flexor surface. Femora not particularly swollen.

Remarks. Grandixyela is assigned to Syspastoxyelidae based on the synapomorphies of the family including forewing venation strongly contracted basally, with distal 0.4 of wing veinless and densely longitudinally corrugated, antennal thread with much elongated composite first flagellomere, cerci 3-segmented and tibiae strongly spinose. Grandixyela is distinct from all known syspastoxyelids by the narrow and completely sclerotized pterostigma and, except for Syspastoxyela , by RS reaching wing margin at a short distance from pterostigma.

Grandixyela is distinguished from other genera in having pronotum short (vs. pronotum remarkably elongate; a unique feature in Deltoxyela ); pterostigma narrow and completely sclerotized (vs. narrow and not sclerotized in Pinguixyela , wide and completely sclerotized in Deltoxyela , Pinguixyela and Striaexyela , wide and not sclerotized in Syspastoxyela ); RS reaching wing margin beyond apex of pterostigma (vs. joining pterostigma in all genera but Syspastoxyela ), 1-RS elongate, not dot-like (vs. dot-like in Burmoxyela ), 2r-rs positioned near midlength of pterostigma (vs. near one-third length of pterostigma in Pinguixyela ). With the body almost 5 mm long, G. rasnitsyni is the largest syspastoxyelid sawfly known. All comparisons are shown in Table 1 .