Dr. Miller actively researches the taxonomy of a number of Late Mesozoic to Early Cenozoic floras from the Western Cordillera of North America. Including the Upper Jurassic Temple Canyon flora from the Morrison Formation near Cañon City in Colorado, the Early Cretaceous Winthrop Formation flora from north central Washington State, and the Denver Basin flora from latest Cretaceous and Early Paleocene rocks on the eastern flank of the Front Range.
The Temple Canyon flora is a rare glimpse into a complete Late Jurassic lacustrine ecosystem. The lake beds preserve an abundant flora and fauna distinct from those previously described from the Morrison Formation. The diverse floral assemblage includes species of algae, bryophytes, ferns, ginkgophytes, horsetails, cycads, bennettites, and conifers indicative of a warm, humid climate. This is in contrast to the semiarid “savannah” ecosystem often argued as the modal paleoclimate during Morrison time. Dr. Miller is working on this flora in collaboration with colleagues at CU Boulder and Dr. Carpenter at DMNS.
Dr. Miller’s work on the Early Cretaceous (~105 Ma) Winthrop Formation flora represents a continuation of his doctoral work at Yale University. Presently, he is working on describing and naming new species of ferns from the flora and documenting paleoecological patterns of major plant clades in the formation. Results of these studies include the earliest reported examples of several important fern clades and new perspectives on the ecological distribution of angiosperm vs. non-angiosperm plants during the time of rapid radiation of the angiosperm clade.
The Denver Basin Project, an NSF-funded project to study the effects of significant environmental and tectonic events on floras, ecosystems, and climate in the Denver Basin, has led to Dr. Miller’s work on the latest Cretaceous and Early Paleocene (~68–64 Ma) Denver Basin flora. The current taxonomic project considers the description and nomenclature of the most common and well-preserved fossil species in the Denver Basin (~50 species). Results of this work will help to elucidate floral change across the KT boundary in the Denver Basin.
