New fossil records of Xyelidae (Hymenoptera) from the Middle Jurassic of Inner Mongolia, China

Yan Zheng,Dong Chen,Jun Chen,Haiyan Hu,Haichun Zhang,Alexandr P Rasnitsyn

doi:10.5852/ejt.2021.733.1229

Abstract

A new genus and two new species of Xyelidae Newman, 1834 (Hymenoptera Linnaeus, 1758), Platyxyela tenuis sp. nov. and Scleroxyela daohugouensis gen. et sp. nov. are described and illustrated from the Middle Jurassic Daohugou Beds of Ningcheng, Inner Mongolia, China. Platyxyela tenuis sp. nov. (Xyelinae Newman, 1834, Liadoxyelini Rasnitsyn, 1966) can be distinguished from its congeners by short forewing length and ovipositor sheath strongly narrowed toward acute apex. Scleroxyela daohugouensis gen. et sp. nov. is placed within Macroxyelinae Ashmead, 1898, Xyeleciini Benson, 1945 based on pterositigma completely sclerotised and costal space sclerotised before ptrostigma, 1-Rs half as long as 1-M, and 1m-cu short. It is the first recorded species of Xyeleciini in Daohugou Beds. Furthermore, an updated key of identification of subfamilies and tribes of Xyelidae is provided. Our findings of new morphological data provide insights into the early evolution of Hymenoptera, as well as effectively enrich our understanding of the diversity of Xyelidae in the Mesozoic.  A correction has been published: Zheng Y., Hu H., Chen D., Chen J., Zhang H. & Rasnitsyn A.P. 2023. New fossil records of Xyelidae (Hymenoptera) from the Middle Jurassic of Inner Mongolia, China – Corrigendum. European Journal of Taxonomy 860: 181–182. https://doi.org/10.5852/ejt.2023.860.2059

Highlights

The small extant group of distinctive sawflies, Xyelidae Newman, 1834, has been considered to be the most primitive of Hymenoptera Linnaeus, 1758 (Rasnitsyn 1980; Zhang & Zhang 2000), and plays a vital role as an ancestral group in the early evolution of hymenopterans
Scleroxyela daohugouensis gen. et sp. nov. is placed within Macroxyelinae Ashmead, 1898, Xyeleciini Benson, 1945 based on pterositigma completely sclerotised and costal space sclerotised before ptrostigma, 1-Rs half as long as 1-M, and 1m-cu short
The small extant group of distinctive sawflies, Xyelidae Newman, 1834, has been considered to be the most primitive of Hymenoptera Linnaeus, 1758 (Rasnitsyn 1980; Zhang & Zhang 2000), and plays a vital role as an ancestral group in the early evolution of hymenopterans. This family has been reported as the earliest appearance on the hymenopteran cladogram from the Middle or Upper Triassic of Kyrgyzstan (Rasnitsyn 1964, 1969, 1980), and the Upper Triassic of Australia (Riek 1955; Engel 2005), South Africa (Schlüter 2000) and Argentina (Lara et al 2014)

Summary

Introduction

The small extant group of distinctive sawflies, Xyelidae Newman, 1834, has been considered to be the most primitive of Hymenoptera Linnaeus, 1758 (Rasnitsyn 1980; Zhang & Zhang 2000), and plays a vital role as an ancestral group in the early evolution of hymenopterans This family has been reported as the earliest appearance on the hymenopteran cladogram from the Middle or Upper Triassic of Kyrgyzstan (Rasnitsyn 1964, 1969, 1980), and the Upper Triassic of Australia (Riek 1955; Engel 2005), South Africa (Schlüter 2000) and Argentina (Lara et al 2014). We report the discovery of one new genus and two new species, Platyxyela tenuis sp. nov., and Scleroxyela daohugouensis gen. et sp. nov. based on two well-preserved xyelid specimens from the Middle Jurassic Daohugou Beds of European Journal of Taxonomy 733: 146–159 (2021)

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