中国东北中生代沫蝉总科（昆虫纲：半翅目）生物系统学研究

The superfamily Cercopoidea is one of the most speciose insect groups of the Cicadomorpha. Both nymph and adult cercopoids injure plants through sucking plant fluids and transmitting plant viruses. The earliest cercopoids appeared in the Late Triassic. So far, A considerable amount of Mesozoic cercopoid fossils have not been studied, and only about 45 species within nearly 15 genera of three families (Procercopidae, Sinoalidae, and Cercopionidae) have been reported from Eurasia and South America. The Mesozoic strata of northeastern China yields a mass of fossil hoppers (Cicadomorpha and Fulgoromorpha), of which the most abundant group is the the superfamily Cercopoidea, that outnumber all other hoppers, such as Palaeontinoidea and Cicadoidea (Tettigarctidae). However, the research on the systematic biology of cercopoids is far from sufficiency, compared to other cicadomorph groups. Although to date, almost all of the genera of the Mesozoic Cercopoidea have been recorded in northeastern China, some reported taxa should be revised in detail and meanwhile some genera and species are still unreported. This project seeks to: 1), revise and describe taxa within the superfamily Cercopoidea from the Mesozoic of northeastern China; 2), give the key to the genera of the Mesozoic Cercopoidea and improve its taxonomic system; 3), reconstruct phylogenetic relationships within the Mesozoic cercopoids based on cladistic analysis to infer their origin, diversification, and the relationship between the early cercopoids and their modern descendants. In the middle-late stage of Mesozoic, basal cercopoids became extinct, and mordern group has already appeared and became to diversify. Our earlier study indicated that fossil cercopoids collected from the Mesozoic strata of northeastern China contains some important information about the evolutionary process that the basal cercopoids evolved to their modern descendants. Therefore, this project has great significance not only in investigating, exploring, and recording the bio-diversity of the Mesozoic cercopoidea but also in infering the history of the origin and diversification of the ancestral group of mordern cercopoids.

沫蝉是蝉下目昆虫生物多样性非常高的一个类群，最早出现于晚三叠世。目前，已报道中生代沫蝉化石种类并不十分丰富。中国东北中生代地层产出了大量沫蝉化石，其数量远超蝉类（头喙亚目）其它类群。世界上已报道中生代沫蝉绝大部分的属已在该地区发现，但其分类混乱，需要进行分类学修订，同时一些类群依然未得到正式记述。本项目拟对中国东北中生代地层已描述沫蝉类群在分类学上进行补充、整理和修订并描述新类群，进而制定中生代沫蝉分类检索表，完善其分类体系。在此基础上，利用支序分类学分析手段对早期沫蝉类群进行系统发生关系重构，并基于其结果推断沫蝉基干类群的起源、演化和古地理分布等。中生代中晚期基干沫蝉衰亡而现代沫蝉开始兴起，我们前期的研究表明中国东北中生代地层产出的沫蝉化石包含这一演化历程的重要信息，因而本项目不仅有助于更深入了解中生代基干沫蝉的生物多样性而且对探究现代沫蝉起源及早期演化也具重要意义。

沫蝉总科自三叠纪末期独立分化以来，多样性程度及个体丰度一直较高，但以往对该昆虫类群早期演化历史的研究非常薄弱，其分类体系也存在诸多问题。本项目系统收集了中国东北中生代地层产出的沫蝉化石，并以缅甸白垩纪琥珀中保存的标本为补充，1），共报道中生代沫蝉1个新亚科、1个新族、4个新属及6个新种；2），基于详尽的分类学修订，共建立7个新属种组合；3），制定了属级水平的分类检索表。以上研究工作完善了中生代沫蝉的分类体系。另外，利用支序分类学分析手段重构演化关系，揭示了沫蝉总科内系统关系为：华翅蝉科+（原沫蝉科+（Cercopionidae +现代沫蝉类群））；华翅蝉科内系统关系为：（Juroalinae +（Sinoalini + Fangyuanini））；原沫蝉科内系统关系为：（Titanocercopis + Jurocercopis + Cretocercopis）+（Procercopis + Procercopina +（Anthoscytina +（Stellularis + Sinocercopis）））。为了能够通过对比分析更好揭示早期沫蝉分化特点及演化特征，对半翅目其它类群特别是蝉下目（古蝉总科、类杆蝉总科、叶蝉总科和蝉总科）的中生代化石标本进行了研究，共报道1个新科、7个新属、15个新种、2个新属种组合。本项目研究结果表明：1）、与蝉下目其它类群相比，中生代沫蝉形态多样性程度相对较高；2）、雌性个体数量优势极其明显的Juroala daohugouensis Chen & Wang, gen. et sp. nov.的发现意味着早期沫蝉在生理、生态、行为等方面可能已强烈分化；3）、与蝉下目其它现生类群类似，沫蝉原始类群在三叠纪末期出现，侏罗纪持续繁荣，并于白垩纪中期在被子植物替代裸子植物过程中持续衰退并最终消亡，与此同时沫蝉现代类群陆续出现。本项目的研究结果对理解基干沫蝉多样性及演化特征、现代沫蝉起源历史及驱动因素等都具有重要意义。