Assessing the temporal patterns of mid-Cretaceous floral change in Portugal - a palynological and chemostratigraphic approach

在白垩纪中期，被子植物在生态上占主导地位的同时，许多裸子植物和蕨类植物谱系的多样性急剧下降。与早期被子植物的生物学和系统关系的丰富信息相反，它们的进化和辐射的时间模式及其对共存植物群落的影响仍然受到很大的限制。在这里，我建议研究的海洋近岸和大陆沉积物的化石花粉协会，从葡萄牙卢西塔尼亚盆地，一个地区众所周知的特殊被子植物中化石植物群。含花粉的海相地层的年龄确定将以生物地层学以及高分辨率C和Sr同位素地层学为基础。这两个研究领域的孢粉植物区系将进行定性和定量分析，使用最新的显微镜技术（DIC-TL，CLSM，SEM），特别侧重于被子植物花粉。与海洋来源的花粉记录的相关性将提供一个改进的年龄限制著名的中化石植物群的北方卢西塔尼亚盆地。结合化学地层学和孢粉学的方法，这一建议将提供新的见解陆地生态系统的动态在阿尔比-早森诺曼期间的被子植物的显着多样化的关键阶段。

The rise of angiosperms to ecological dominance during the mid-Cretaceous coincided with a dramatic drop in the diversity of many gymnosperm and pteridophyte lineages. In contrast to the wealth of information available on the biology and systematic relationships of early angiosperms, the temporal patterns of their evolution and radiation and its impact on coexisting plant communities are still poorly constrained. Here, I propose to study the fossil pollen associations of marine near-shore and continental deposits from the Portuguese Lusitanian Basin, an area well known for its exceptional angiosperm mesofossil floras. Age assignment of the pollen-bearing marine strata will be based on biostratigraphy coupled with high-resolution C- and Sr-isotope stratigraphy. The palynofloras of both study areas will be analysed qualitatively and quantitatively using up-to-date microscopy techniques (DIC-TL, CLSM, SEM) with special focus on angiosperm pollen. Correlation with the marine-derived pollen record will provide an improved age constraint for the famous mesofossil floras of the northern Lusitanian Basin. The combined chemostratigraphic and palynological approach of this proposal will provide new insights into terrestrial ecosystem dynamics during a critical phase of pronounced diversification of angiosperms during the Albian-Early Cenomanian.