- I have focused my scientific career on several research lines within Paleobotany, a Plant Science sub-discipline, with the goal of answering some key questions such as the origin of angiosperms, the evolution of seed plant characters through time, evolution of floras in the Southern Hemisphere, the influence of climate on these floras, and paleoenvironmental reconstructions. I have concentrated in two areas that are related to one another: diversification and evolution of angiosperms and their paleoenvironments during the Cretaceous, and evolution of Late Cretaceous-Tertiary paleofloras of Patagonia, Argentina. For accomplishing these projects, I have used traditional paleobotanical approaches (descriptions and comparisons of fossils with extant materials), modern and cutting-edge laboratory techniques (SEM, TEM and CT-Scan technology with 3-D reconstructions), and combined these with modern analytical methods (e.g., the inclusion the fossils within in phylogenetic analyses, combined with molecular DNA sequence data from modern taxa). During 2000, I started a line of research with colleagues from Pennsylvania State University, the Smithsonian Institution, the Egidio Feruglio Museum in Patagonia (MEF, where I am a Adjunct Sr. Researcher), and the Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina. We are studying several floras of Early Cretaceous to Oligocene age of Patagonia, Argentina. This project is almost complete, and has vastly improved our understanding of the floristic composition, distribution patterns and migration routes of these paleofloras. These results will provide data for those researchers interested in the relationships of climate, flora, fauna and biogeography of the past and modern Southern Hemisphere. The floras we have newly described are rich in Australasian lineages (such as Eucalyptus, Ceratopetalum) and surprisingly include several elements of Northern Hemisphere origin (e.g. Juglandaceae and Bixaceae). These floras provide critical data for understanding the modern biotic distribution of both hemispheres, and will help address several questions such as how, why (climatically), when and where this extraordinary biotic diversity evolved. We are accumulating an incredible amount of data that is fundamental for answering these questions, and that has already allowed us to begin the reconstruction of paleoenvironments and climate history. I am also working on imaging and digitalization of the Cornell University Plant Anatomy Collection (CUPAC).