9801607 Foote The origin of the seed in the Late Devonian was a key innovation that facilitated the exploitation of a wide range of terrestrial environments and diverse ecological strategies during the early evolution of plants on land. Throughout the late Paleozoic, seed plants radiated in environments with ecological dynamics and organization that were fundamentally different from those of the Recent, most notably in the absence of tetrapod herbivory, limited direct plant-insect interactions, and strong phylogenetic partitioning of ecological strategies among different plant groups. The fossil seed record of the late Paleozoic provides an opportunity to study how increasing complexity and modernization of ecological interactions was reflected in structural adaptations to protect and disperse propagules. The research proposed here includes analyses of taxonomic diversity and morphological disparity in subclades of late Devonian to Permian fossil seed plants. The evolutionary significance of seed size will be examined by testing for trends in volume. A morphospace based on seed morphology will be used to test hypothesized patterns of morphological and ecological overlap among seed plant subclades. This research will be the first quantitative treatment of macroevolutionary patterns during the early history of a major group of land plants and will contribute to understanding of the unique structure of late Paleozoic terrestrial ecosystems.
