Cretaceous Paleobotany and Its Bearing on the Biogeography of Austral Angiosperms

Abstract

Plant fossils from Antarctica have played a major role in developing concepts of the geological history of the Southern Hemisphere. Disjunct austral distributions of extant taxa (e.g., Hooker 1853) and the strong floristic similarities between the Permo-Triassic Glossopteris floras on the austral land masses (e.g., Halle 1937) were important in establishing that now separate continental areas were once contiguous. Since widespread acceptance of continental drift, paleobotanical contributions to ideas of continental realignment have emphasized the delimitation of floristic provinces (``phytochoria'' sensu Meyen 1987) and assessments of overall similarities among fossil floras from different areas (e.g., Chaloner and Meyen 1973, Chaloner and Lacey 1973, Vakhrameev et al. 1978, Chaloner and Creber 1988). An alternative approach, made possible by recent developments in systematics, uses patterns of phylogenetic relationship in different taxa to develop and test hypotheses about relationships between different areas and patterns of geographical fragmentation (Brundin 1966, Rosen 1978, Nelson and Platnick 1981, Nelson and Rosen 1981, Platnick and Nelson 1978, Humphries and Parenti 1986).