Terrestrial plant diversity experienced dramatic changes during the Cretaceous Period (145-66 Ma). Throughout this time angiosperms (flowering plants) experienced their initial radiation and as a result terrestrial ecosystems began to resemble modern ones as many forests transitioned from gymnosperm dominated to angiosperm dominated. This triggered diversification events in bryophytes and ferns while conifers and other gymnosperms are believed to have experienced dramatic turnovers. Therefore, in order to further our understanding of how modern terrestrial floras developed, it is critical to study plant evolution and diversity during the Cretaceous. My research program focuses on furthering our understanding of this evolutionary event by recovering and characterizing Late Cretaceous (100-66 Ma) fossils that are three dimensionally-preserved, often down to the cellular level, from undersampled regions including the western coast of North America and western Antarctica. Such fossils are providing unparalleled and critical details in the systematics, phylogenetic diversification, and biology during this important interval of biotic change.