Integrated phylogenomic and fossil evidence of stick and leaf insects (Phasmatodea) reveal a Permian-Triassic co-origination with insectivores

Stick and leaf insects (Phasmatodea) are a distinctive insect order whose members are characterised by mimicking various plant tissues such as twigs, foliage, and bark. Unfortunately, the phylogenetic relationships among phasmatodean subfamilies and the timescale of their evolution remain uncertain. Recent molecular clock analyses have suggested a Cretaceous-Palaeogene origin of crown Phasmatodea and a subsequent Cenozoic radiation, contrasting with fossil evidence. Here we analysed transcriptomic data from a broad diversity of phasmatodeans and, combined with the assembly of a new suite of fossil calibrations, we elucidate the evolutionary history of stick and leaf insects. Our results differ from recent studies in the position of the leaf insects (Phylliinae), which are recovered as sister to a clade comprising Clitumninae, Lancerocercata, Lonchodinae, Necrosciinae, and Xenophasmina. We recover a Permian to Triassic origin of crown Phasmatodea coinciding with the radiation of early insectivorous parareptiles, amphibians, and synapsids. Aschiphasmatinae and Neophasmatodea diverged in the Jurassic–Early Cretaceous. A second spur in origination occurred in the Late Cretaceous, coinciding with the Cretaceous Terrestrial Revolution, and was likely driven by visual predators such as stem birds (Enantiornithes) and the radiation of angiosperms.

竹节虫目（Phasmatodea）是一类极具辨识度的昆虫类群，其所有成员均以拟态枝条、叶片、树皮等多种植物组织为典型特征。遗憾的是，竹节虫各亚科间的系统发育关系，以及该类群的演化时间尺度至今仍未明确。此前的分子钟分析曾提出，冠群竹节虫起源于白垩纪-古近纪，并在新生代发生后续的辐射演化，这一观点与化石证据存在矛盾。本研究通过分析涵盖广泛类群的竹节虫转录组数据，并结合全新构建的化石校准数据集，系统阐明了竹节虫的演化历史。本研究结果与近期相关研究关于叶䗛亚科（Phylliinae）系统位置的结论存在显著差异：叶䗛亚科被推断为包含棒竹节虫亚科（Clitumninae）、刺尾类群（Lancerocercata）、长角竹节虫亚科（Lonchodinae）、瘦竹节虫亚科（Necrosciinae）以及异竹节虫属（Xenophasmina）的演化支的姊妹群。本研究推断，冠群竹节虫的起源时间为二叠纪至三叠纪，这一时间节点与早期食虫副爬行动物、两栖动物以及合弓动物的辐射演化高度重合。阿氏竹节虫亚科（Aschiphasmatinae）与新竹节虫下目（Neophasmatodea）在侏罗纪至早白垩世发生分化。第二次起源加速事件发生于晚白垩世，与白垩纪陆地革命（Cretaceous Terrestrial Revolution）的时间窗口高度吻合，其驱动机制可能包括以反鸟类（Enantiornithes）为代表的基干视觉捕食者的演化，以及被子植物的辐射扩张。