New fossils of the giant African crocodyliform Sarcosuchus imperator clarify its skeletal anatomy, growth patterns, size, longevity, and phylogenetic position. The skull has an expansive narial bulla and elongate jaws studded with stout, smooth crowns that do not interlock. The jaw form suggests a generalized diet of large vertebrates, including fish and dinosaurs. S. imperator is estimated to have grown to a maximum body length of at least 11 to 12 meters and body weight of about 8 metric tons over a life-span of 50 to 60 years. Unlike its closest relatives, which lived as specialized piscivores in marginal marine habitats, S. imperator thrived in fluvial environments.