Cretaceous and paleogene vegetation of western Canada: organismal and floristic evolution

白垩纪和古近纪是维管植物区系演化史上最剧烈的时期。 在此期间，开花植物出现，多样化，并上升到主导地位。 蕨科蕨类植物和松科针叶植物经历了显著的进化辐射。 许多其他类群，如蕨类植物和裸子植物，多样性显著减少，或类群灭绝。 进化营业额伴随着物种丰富度的急剧增加，与生态复杂性的增加。 开花植物占主导地位的森林取代了针叶树和苏铁。 蕨类植物辐射到生态位所产生的植物群落的复杂性增加。 松科针叶树多样化，以高地和干燥的生境为主。 在森林的地面上，草本地被植物发生了显着的变化，这可以从新物种的进化中看出，包括石松、石松和木贼，以及蕨类植物的爆炸性辐射。 加拿大西部的气候发生了巨大的变化，年平均气温从热带条件下降。 阿尔伯塔和不列颠哥伦比亚省是研究这些变化的独特之地，因为它们是北美植物化石最丰富的地区。 阿尔伯塔中部和南部的压缩植物群允许描述许多新物种、全株重建以及在生长和沉积环境背景下的植物群特征。 在世界著名的普林斯顿燧石中发现了最壮观的植物化石，在温哥华岛和太平洋沿岸的碳酸盐海洋结核中发现了几种新的化石。 使用传统的技术来研究解剖学，形态学和植物发生学，以及三维重建，epifluorescence，CLSM，SEM和TEM的新方法，我们将研究来自一些网站的化石植物的进化。研究将集中在最后的前被子植物植被，早期被子植物区系和火灾的历史，水生植物区系，以及来自不列颠哥伦比亚省和阿尔伯塔始新世森林的果实和种子。

The Cretaceous and Paleogene witnessed the most dramatic floristic evolution in the history of vascular plants. During this time flowering plants appeared, diversified and rose to dominance. Filicalean ferns and pinaceous conifers underwent significant evolutionary radiations. Many other groups such as pteridophytes and gymnosperms suffered significant reductions in diversity or taxa became extinct. Evolutionary turnover was accompanied by a dramatic increase in species richness, correlated with an increase in ecological complexity. Flowering plant dominated forests replaced conifers and cycads. Ferns radiated into niches produced by increased complexity of plant communities. Pinaceous conifers diversified to dominate upland and drier habitats. On the forest floor there was significant change in herbaceous ground cover as seen by the evolution of new species of bryophytes, lycopods and horsetails, and an explosive radiation of ferns. Climate of western Canada changed dramatically as mean annual temperatures decreased from tropical conditions. Alberta and BC are uniquely suited for studying these changes because they yield some of the most abundant sources of plant fossils in North America. Compression floras of central and southern Alberta allow description of many new species, whole plant reconstructions and characterization of floras in the context of their environments of growth and deposition. The most spectacular occurrences of anatomically preserved fossil plants are from the world famous Princeton Chert and several new sources of fossils in carbonate marine nodules from Vancouver Island and the Pacific coast. Using traditional techniques to study anatomy, morphology, and phylogeny, as well as newer methods for three-dimensional reconstruction, epifluorescence, CLSM, SEM, and TEM, we will investigate the evolution of fossil plants from a number of sites. Studies will center on the last pre-angiospermous vegetation, early angiospermous floras and the history of fires, aquatic floras, and fruits and seeds of Eocene forests from British Columbia and Alberta.