Potrerilloxyela menendezi Lara et al. 2014 (Hymenoptera: Xyelidae) from the Upper Triassic of Argentina revisited to explore transformation of the cubital vein in Hymenoptera

Abstract

Here, we report on our restudy of the holotype of Potrerilloxyela menendezi Lara, Rasnitsyn and Zavattieri 2014, focusing on the forewing. We found that the bases of cubitus and the anterior cubitus vein, normally lost in Hymenoptera, are present in Potrerilloxyela menendezi probably as a reversion (atavism). Other cases of reversions are rare in Hymenoptera: this being the oldest known, and the most similar to the groundplan of cubital system in Pterygota. Additionally, we discuss modifications of the cubital system observed in fossil and extant hymenopterans.