NAGALINGUM, NATHALIE S*, ANDREW N DRINNAN, STEPHEN MCLOUGHLIN, AND RICHARD LUPIA. School of Botany, The University of Melbourne, Parkville, Victoria, Australia, 3052; School of Geology and Geophysics, University of Oklahoma, Norman, OK, USA 73072. - Patterns of pteridophyte evolution and diversification in the Cretaceous of southern Gondwana.
Palynological data provide an informative record of pteridophyte
history because spores are sampled from habitats beyond the immediate
area of deposition. This data complements macrofossil data about
local fluvial and lacustrine taxa. Palynological data is recorded as
dispersed spores and pollen in numerous Cretaceous studies of
Australian and Antarctic sediments, bore cores and wells. Once
compiled into a database these records can potentially form a large
and comprehensive data set for examining patterns of pteridophyte
biogeography and evolution during the Cretaceous. The Cretaceous
North American palynofloras exhibit a decline in abundance and
diversity of ferns that coincides with the evolution and later
overwhelming floristic dominance of angiosperms. However, patterns of
fern evolution have yet to be investigated for the Southern Hemisphere
continents of Gondwana. We present the results of the analysis of
Australian and Antarctic palynomorphs from over 100 references showing
changes in fern abundance, diversity and distribution.
Key words: Antarctica, Australia, Cretaceous, palynology, pteridophyte