Paleontology has undergone a renaissance in the past 50 years, expanding from an empirical field focused on stratigraphic context to the theoretically grounded discipline of paleobiology. This transformation has been propelled by conceptual advances in two broadly construed areas, evolution and paleoecology. Phylogenetic systematics has revised our understanding of the evolutionary relationships among organisms. New understanding of tempo and mode in evolution, evolutionary hierarchies, the role of mass extinctions and recoveries, and developmental evolution has led to unexpected insights on evolutionary processes. Within paleoecology, taphonomy has led to greater understanding of the nature of the fossil record. Evolutionary paleoecologists have unearthed temporal and spatial patterns, at various scales, in diversity and community organization and have investigated the processes responsible for them. Other advances in paleoecology involve trace fossils; paleobiogeography; novel uses of fossils in understanding the environment; and the new discipline of conservation paleobiology. New concepts have been furthered by incorporating tools from other disciplines, including quantitative analytical methods, biostratigraphic innovations, geochemical and molecular tools, and advanced microscopy techniques. Fueling these advances are fossil discoveries revealing previously unknown Archean-Proterozoic worlds, detailed accounts of the explosion of life in the Cambrian, and floras and faunas yielding surprising and unexpected insights into the origins and evolution of important plant and animal groups.