2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 11
Presentation Time: 4:00 PM

POLLEN AND SPORE ASSEMBLAGE FROM THE LATE PALEOCENE ALMONT LAGERSTÄTTEN


PIGG, Kathleen B., School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287-4501, DEVORE, Melanie L., Department of Biological & Environmental Sciences, Georgia College & State University, 135 Herty Hall, Milledgeville, GA 31061, FARABEE, Micheal J., Estrella Mountain Community College, 3000 N Dysart Road, Avondale, AZ 85323 and ZETTER, Reinhard, Department of Palaeontology, University of Vienna, Althanstrasse 14, Vienna, A-1090, Austria, kpigg@asu.edu

The Almont flora is known for its rich array of plant megafossils. The depositional environment responsible for the exceptional preservation of leaves, fruits, and seeds also preserves a rich pollen and spore assemblage within the silicified shale. Unlike material from lignites, silicification permits the three dimensional preservation needed to assess key systematic features. The assemblage includes 65 taxa of pteridophytes (5), gymnosperms (11), and angiosperms (49). The dominant taxa include Juglandaceae, Betulaceae and other wind dispersed forms. Of particular significance are forms lacking a megafossil record that are represented among the microfossils. These include: pteridophytes, Araucariaceae, Podocarpaceae, Bignoniaceae, Ericaceae, Eucommiaceae, and Ulmaceae. A unique opportunity exists to assess variation of taxonomic forms since in situ material from the Cupressaceae, Hamamelidaceae, Juglandaceae, and Platanaceae is present. Pollen may also be of predictive value in documenting the occurrence of families that may also be present in the megafossil record (e.g. possibly Buxaceae). Together the Almont mega- and microfloras provide a rare snapshot of the diversity of Late Paleocene floras and their systematic affinities.