Carnosaurs

Carnosaurs, or carnosaurians, are extinct predatory dinosaurs in the large group Carnosauria that lived during the Jurassic and Cretaceous periods. Starting from the 1990s, scientists have discovered some very large carnosaurs in the carcharodontosaurid family, such as Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan which are among the largest known predatory dinosaurs.

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. However, with the description and publication in 2019 of Asfaltovenator vialidadi, a basal allosauroid curiously displaying both primitive and derived features seen in Tetanurae, the new phylogenetic analysis has found Megalosauroidea to be a basal grade of carnosaurs in respect to Allosauroidea; thus significantly expanding Carnosauria's inclusiveness towards its original context.

Distinctive characteristics of carnosaurs include large eyes, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia).

Carnosaurs 1st appeared in the Middle Jurassic, around 176 mya. The last definite known carnosaurs, the carcharodontosaurs, became extinct in the Turonian epoch of the Cretaceous, roughly 90 mya; reportedly later remains of carcharodontosaurids, from the late Maastrichtian (70–66 Ma ago) Bauru Group in Brazil, were later interpreted as those of abelisaurids. The phylogenetically problematic megaraptorans, which may or may not be carnosaurs, became extinct around 66 mya. Unquillosaurus is another possible carnosaurian theropod that has an extended range, hailing from rocks dated to the Campanian, around 75-70 mya.