Paleodiversity of Paleogene hymenopteran insects and their interactions with flowers

无论是现在还是过去，昆虫在陆地生态系统中都扮演着至关重要的角色，并表现出显著的生物多样性，但它们仍未得到充分的研究。特别是种类繁多的膜翅目昆虫在植物-昆虫相互作用和传粉生物学中起着重要作用。本项目旨在利用古近纪与现代的直接古生物学证据，研究昆虫-花相互作用的进化和选定膜翅目昆虫群体的古生态学。化石膜翅目昆虫的古生物多样性将与现存分类群进行密切比较。通过分析保存在这些昆虫身上或体内的花粉粒，该项目旨在推断不同膜翅目昆虫科和属的生态作用，并确定它们所访问的植物群。对觅食行为、摄食行为和授粉生物学的深入了解将有助于我们理解花虫相互作用在地质时期的演变。膜翅目昆虫因其与开花植物之间复杂的生态相互作用而特别适合我们的计划调查。研究将集中在Fossillagerstätten Messel和Enspel（都位于德国），它们分别提供了始新世和渐新世时期的见解。这些时间窗口将与当前进行比较，从而提供一个供分析的时间表。始新世特别有趣，因为它的二氧化碳水平升高，全球气候变暖，它可以作为我们未来气候的模拟物。Messel和Enspel都发现了许多保存完好的膜翅目化石，并且可以从这些化石中提取保存完好的花粉粒。将采用创新的方法对化石花粉进行可靠的鉴定，并将其与现存植物科和属进行分类。对花粉采集和传粉的不同生态方面的结论将成为可能。这些发现将丰富研究类群的化石记录，拓宽古生态学的知识。这些分析将与现存的膜翅目昆虫和开花植物分类群进行密切比较，为研究这些类群在当前气候变化方面的进化提供机会。群落生态学和网络分析方法的应用可以为膜翅目昆虫与开花植物的相互作用以及与现代生态系统的比较提供独特的见解。

Both today and in the past insects play crucial roles in terrestrial ecosystems and exhibit remarkable biodiversity, yet they remain understudied. Especially the mega-diverse hymenopteran insects play major roles in plant-insect interactions and pollination biology. This project aims to investigate the evolution of insect-flower interactions and the paleoecology of selected groups of hymenopteran insects by using direct paleontological evidence from the Paleogene in comparison to the present day. The paleobiodiversity of fossil hymenopterans will be investigated in close comparison to extant taxa. By analyzing in-situ pollen grains preserved on or in the bodies of these insects, the project aims to infer the ecological roles of different hymenopteran families and genera and identify the plant groups they visited. Insights into foraging behavior, feeding behavior, and pollination biology will contribute to our understanding of the evolution of flower-insect interactions over geological time. Hymenopteran insects are especially suited for our planned investigations due to their complex ecological interactions with flowering plants. The research will focus on the Fossillagerstätten Messel and Enspel (both located in Germany), which offer insights into the Eocene and Oligocene periods, respectively. These time windows will be compared with the present day, providing a timeline for analysis. The Eocene is of special interest, because with its elevated CO2-level and globally warm climate, it may serve as an analog for our future climate. Both Messel and Enspel have yielded numerous excellent preserved hymenopteran fossils, and exquisitely preserved in-situ pollen grains can be extracted from those fossils. Innovative methods will be employed to reliably identify the fossil pollen, classifying them with extant plant families and genera. Conclusions on different ecological aspects of foraging of pollen and pollination will be possible. These findings will enrich the fossil record of the studied groups and widen the knowledge on paleoecology. The analyses will be done in close comparison to extant taxa of both hymenopteran insects and flowering plants, providing opportunities for investigating the evolution of these groups in regard to the current climate change. Application of community ecology and network analysis approaches can provide unique insights into the former interactions of hymenopteran insects with flowering plants and how this compares to modern ecosystems.