| dc.description.abstract | The Cedar Mountain Formation is a rich source of information on North American megafauna during the Cretaceous, preserving sediments deposited in floodplains related to the Western Interior Seaway. In this thesis, petrified wood, palynomorphs, and wood fragments are identified in the hopes of further building upon what is known about the environment within which Cretaceous megafauna lived. These remains come from the Short Canyon member at the Moore Road Cutoff section and are the first paleobotanical data from this informal member. The petrified wood is identified as Taxodioxylon albertense, a cupressaceous conifer with affinities to Sequoioidae, especially Sequoia and Sequoiadendron. The growth rings of this wood are analyzed and used to interpret water availability in the tree’s lifetime, using both seasonal and intraseasonal growth rings. A sediment sample for palynological analysis yielded pollen, spores, cuticle, and wood. Palynomorphs are identified to major group—pteridophytes (e.g., club mosses, ferns, and horsetails), gymnosperms (e.g., cycads, ginkgo, and conifers), or angiosperms (flowering plants)—and abundance counts are made to compare to previous palynological assessments in this formation. These produced pteridophyte-dominated abundances, with roughly equal proportions of angiosperm and gymnosperm pollen. Within the debris in these slides are angiosperm wood fragments. Hardwood features are identified and comparisons to angiosperms previously known from this formation (Icacinoxylon and Paraphyllathoxylon) are made. From each of these assessments, the paleoenvironment of the Short Canyon member of the Cedar Mountain Formation is interpreted to be a seasonally wet and temperate floodplain. | en_US |
