青蔵高原で中生代昆虫化石群を初発見（First Mesozoic Entomofauna Discovered on Qinghai-Tibetan Plateau）

2026-04-29 中国科学院（CAS）

中国科学院南京地質古生物研究所の王博教授らによる国際研究チームは、青海省ダチャイダン地区の下部ジュラ紀・小煤溝層から、多様な昆虫化石群「ダチャイダン昆虫相」を発見した。これは青蔵高原で初めて確認された中生代昆虫相であり、高原地域における中生代昆虫進化の解明につながる重要な成果となる。化石群は甲虫類が約48％を占め、ゴキブリ類、カワゲラ類、カメムシ類なども含まれていた。水生昆虫と陸生昆虫が共存していることから、当時の環境は湿地性の河川・沼沢地であったと考えられる。また、カワゲラ類は絶滅群ペルラリオプシス科に属し、ジュラ紀～白亜紀の地層比較や古生態解析に重要な分類群であることも判明した。さらに、この昆虫相は、陸上有機物を基盤とする低栄養型水域生態系を示しており、中国では初の確認例となった。研究は、ジュラ紀の昆虫分布や青蔵高原の古環境進化を復元する上で重要な手掛かりを提供している。

Representative fossils from Dachaidan Entomofauna (a) stonefly (Plecoptera: Perlariopseidae Sinitshenkova, 1985); (b) cockroach (Blattodea: Caloblattinidae Vršanský & Ansorge, 2000); (c) beetle (Coleoptera: ZygadeniaHandlirsch, 1906); (d) cockroach (Blattodea: Caloblattinidae Vršanský & Ansorge, 2000); (e, f) beetle (Coleoptera: Zygadenia Handlirsch, 1906); (g, h) stonefly nymphs (Plecoptera). (Image by NIGPAS)

＜関連情報＞

青海チベット高原から発見された最初の中生代昆虫相
First Mesozoic entomofauna from the Qinghai-Tibetan Plateau

Qianqi Zhang, Jun Chen, Jiahao Li, Chunpeng Xu, Zhengyu Song, Yan Fang, Daran Zheng, Edmund A. Jarzembowski, Haichun Zhang, Bo Wang
Fundamental Research Available online: 17 April 2026
DOI:https://doi.org/10.1016/j.fmre.2026.04.013

The Qinghai-Tibetan Plateau, as the highest plateau on Earth and ‘the Third Pole’, has witnessed the origin and evolution of the Tibetan biotas [1]. Mesozoic non-marine sediments are widely distributed in the northern (Qaidam Basin) and eastern parts of the Qinghai-Tibetan Plateau, containing abundant terrestrial fossils (plants and animals) [2]. Despite being the most diverse terrestrial flying animals on Earth, only a few Mesozoic insects have been reported from this plateau [3]. Here, we report a diverse fossil insect assemblage from the Lower Jurassic Xiaomeigou Formation in the Qaidam Basin, which represents the first known Mesozoic entomofauna from the Qinghai-Tibetan Plateau.

We collected 118 fossil insects from the Hongshankuangou outcrop (37°51ʹ59.39ʺ N, 95°15ʹ54.77ʺ E; H = 3141 m) in Dachaidan Town, Haixi Mongolian and Tibetan Autonomous Prefecture, Qinghai Province (Fig. S1a-b online) and therefore name them as the Dachaidan Entomofauna. The insect-bearing Lower Jurassic Xiaomeigou Formation is composed mainly of coarse fluvio-lacustrine sandstone and mudstone. The fossils were obtained from the grey mudstone intervals with interbedded coal layers in the upper member of this formation (Fig. S1c–e online). The majority of fossil insects (about 82%) are complete, suggesting they underwent only short-distance transport before burial. The insect fragments consist entirely of allochthonous terrestrial forms, primarily represented by beetle elytra and cockroach wings.