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

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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.