Carnosauria is a large group of predatory dinosaurs that lived during the Jurassic and Cretaceous periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs and their closest kin. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as Giganotosaurus and Tyrannotitan which are among the largest known predatory dinosaurs.