Discovery of a new symphytan wasp in the mid-Cretaceous Kachin amber (Hymenoptera, Syspastoxyelidae)

Abstract

The mid-Cretaceous Burmese amber from Kachin State of northern Myanmar provides a scanty but rather diverse fauna of sawflies. Herein Grandixyela rasnitsyni gen. et sp. nov. is described and illustrated on the basis of a well-preserved male specimen from Myanmar amber. The new fossil genus and species is characterized by wing venation and body characters, such as 15-segmented antenna with the first flagellomere distinctly shorter than the remaining, pterostigma narrow and completely sclerotized, 1-RS distinct (not dot-like), RS distal of 2r-rs gently S-shaped, ending to pterostigma beyond its apex for a short distance. A checklist and a review of known syspastoxyelid species are discussed. Additionally, our findings not only provide important morphological characters, especially the well-preserved details of the venation and genitalia, but also broaden new data on the Cretaceous diversity of symphytan wasps and further extend the records of syspastoxyelids to six genera and seven species.