Kathleen B. Pigg
My research centers on integrating the plant fossil record with extant morphological and molecular data to better understand phylogeny, biogeography and character evolution in selected families of ferns and flowering plants. Exceptionally preserved fossils that provide detailed floral and fruit structure and often anatomical preservation are used to maximize taxonomic characters that can be compared closely to those of living relatives. Currently, I am studying floras from three different sources: the late Paleocene of North Dakota, the middle Eocene of Washington and adjacent Canada, and the middle Miocene of Washington. These three floras provide fossil evidence to address significant questions in plant evolution, diversification and biogeography. The Almont flora contains the only known Paleocene-aged plants with anatomical structure, and provides unique details about the early coryloid Betulaceae (hazelnuts), the oldest record of maples (Acer) and dogwoods (Cornus) and early evidence for the herbaceous buttercup family Ranunculaceae. The Eocene Okanogan Highlands floras document the early radiation of many temperate families such as the Rosaceae, which become dominant in the later, cooler and drier conditions of the Neogene. The middle Miocene Yakima Canyon flora documents the "last gasp" of a widespread temperate deciduous forest that includes many plants with disjunct Asian/southeastern North American distributions today, such as the sweet gum Liquidambar and the chain fern Woodwardia. This flora also provides evidence of plant/animal interactions such as oak/cynipid wasp gall/fungal interactions, and fossil dung from conifer needle-eating caterpillars.
Other research includes the study of Glossopteris, a dominant Southern Hemisphere plant of Permian age. Last year (Nishida, et al. 2003) we documented the presence of flagellated sperm, considered basal in seed plants, in this interesting gymnosperm. I also have an ongoing interest in the evolution of isoetalean lycopods, a group that evolved separately from the rest of the vascular plants at an early stage in land plant evolution, and have a rich fossil record that documents their independent achievement of such evolutionary grades as arborescence and seed-like reproduction. Lycopods are inconspicuous today, yet they successfully occupy aquatic niches similar to those of their coal-forming ancestors. My teaching interests include evolutionary, structural, and economic aspects of plant biology.
Selected Publications
Pigg, K. B., S. M. Ickert-Bond, and J. Wen. 2004. Anatomically preserved Liquidambar (Altingiaceae) from the middle Miocene of Yakima Canyon, Washington state, USA, and its biogeographic implications. American Journal of Botany in press (March 2004 issue).
Pigg, KB, SR Manchester, and WC Wehr. 2003. Corylus, Carpinus and Palaeocarpinus (Betulaceae) from the middle Eocene Klondike Mountain and Allenby formations of northwestern North America. International Journal of Plant Sciences 164: 807-822
Pigg, K. B., and W. C. Wehr. 2002. Tertiary flowers, fruits and seeds of Washington State and adjacent areas--Part III. Washington Geology 30: 3-20.
Pigg, K. B. 2001. Isoetalean lycopsid evolution: from the Devonian to the present. American Fern Journal 91:99-114.
Pigg, K.B., W.C. Wehr and S.M. Ickert-Bond. 2001. Trochodendron and Nordenskioldia (Trochodendraceae) from the Middle Eocene of Washington State, U.S.A. Intern. Journal of Plant Sciences 162 (5): 1187-1198.
Pigg, KB and GW Rothwell. (2001). Anatomically preserved Woodwardia virginica (Blechnaceae) and a new filicalean fern from the middle Miocene Yakima Canyon flora of central Washington, USA. American Journal of Botany 88:777-787.
Borgardt, SJ, and KB Pigg. (1999). Petrified acorns from the Miocene of North America and their significance to the evolution of Quercus L. (Fagaceae). American Journal of Botany 86:307-325.