Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, carcharodontósauros: "shark-toothed lizards") is a group of carnivorous theropoddinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled Tyrannosaurus in size. Estimates give a maximum weight of 8–10 metric tons (8.8–11.0 short tons) for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500 kilograms (1,100 lb).
Evolution
Along with the spinosaurids, carcharodontosaurids were the largest predators in the early and middle Cretaceous throughout Gondwana, with species also present in North America (Acrocanthosaurus), Europe (Concavenator) and Asia (Shaochilong).[6] Carcharodontosaurids range throughout the Cretaceous from the Barremian (127-121 million years ago) to the Turonian (94-90 million years ago). Past the Turonian, they were replaced by the smaller abelisaurids in Gondwana and by tyrannosaurids in North America and Asia.[7][8] While some teeth and a maxilla discovered in Maastrichtian deposits of Brazil.[9][10] this identification has been subsequently rejected and the material assigned to abelisaurids after better examination,[11] and there are no reliable records of carcharodontosaurs in South America beyond the end of the Turonian.[7] In December 2011, Oliver W. M. Rauhut described a new genus and species of carcharodontosaurid from the Late Jurassic (late Kimmeridgian to earliest Tithonianfaunal stage, about 154-150 million years ago) of Tendaguru Formation, southeastern Tanzania. This genus, Veterupristisaurus represents the oldest known carcharodontosaurid.[12]
The family Carcharodontosauridae was originally named by Ernst Stromer in 1931 to include the single newly discovered species Carcharodontosaurus saharicus. A close relative of C. saharicus, Giganotosaurus, was added to the family when it was described in 1995. Additionally, many paleontologists have included Acrocanthosaurus in this family (Sereno et al. 1996, Harris 1998, Holtz 2000, Rauhut 2003, Eddy & Clarke, 2011, Rauhut 2011), though others place it in the related family Allosauridae (Currie & Carpenter, 2000; Coria & Currie, 2002). Carcharodontosaurids are characterized by the following morphological characters : Dorsoventral depth of anterior maxillary interdental plates more than twice anteroposterior width, squared, sub-rectangular anterior portion of the dentary, teeth with wrinkled enamel surfaces, presence of four premaxillary alveoli and a premaxillary body taller than long in lateral aspect, opisthocoelous cervical vertebrae with neural spines more than 1.9 times the height of the centrum, large, textured rugosities on the lacrimal and postorbital formed by roofing and forming broad orbital shelves, and a proximomedially inclined femoral head.[13][14]
With the discovery of Mapusaurus in 2006, Rodolfo Coria and Phil Currie erected a subfamily of Carcharodontosauridae, the Giganotosaurinae, to contain the most advanced South American species, which they found to be more closely related to each other than to the African and European forms. Coria and Currie did not formally refer Tyrannotitan to this subfamily, pending a more detailed description of that genus, but noted that based on characteristics of the femur, it may be a gigantosaurine as well.[15]
Bahariasaurus has also been proposed as a carcharodontosaurid, but its remains are too fragmentary to be certain.[17]
Carcharodontosaurids have been proposed as more closely related to abelisaurids, as opposed to the allosaurids. This is due to these two clades sharing some cranial features. However, these similarities appear to derive from parallel evolution between these two groups. A larger number of cranial and postcranial characters support their relationship with allosaurids.[citation needed]
Paleobiology
Growth
Osteohistological analysis of the Meraxes holotype specimen suggests the individual could have been between 39 and 53 years old when it died, having reached skeletal maturity approximately 4 years prior to its death (between 35 and 49 years old), making it the longest-lived non-avian theropod currently known. Meraxes was determined to have grown to large size by extending its growth period (hypermorphosis), rather than increasing its relative growth rate (acceleration) through development as in Tyrannosaurus, to which it was compared.[2][18]
^Novas, de Valais, Vickers-Rich, and Rich. (2005). "A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids." Naturwissenschaften,
^Rodrigo P. Fernandes de Azevedo; Felipe Medeiros Simbras; Miguel Rodrigues Furtado; Carlos Roberto A. Candeiro & Lílian Paglarelli Bergqvist (2013). "First Brazilian carcharodontosaurid and other new theropod dinosaur fossils from the Campanian–Maastrichtian Presidente Prudente Formation, São Paulo State, southeastern Brazil". Cretaceous Research. 40: 131–142. doi:10.1016/j.cretres.2012.06.004.
^Carlos Roberto Candeiro; Philip Currie; Lílian Bergqvist (2012). "Theropod teeth from the Marília Formation (late Maastrichtian) at the Paleontological Site of Peirópolis in Minas Gerais State, Brazil". Revista Brasileira de Geociências. 42 (2): 323–330. doi:10.5327/z0375-75362012000200008 (inactive 1 November 2024).{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
^Delcourt, R.; Grillo, O.N. (2017). "Carcharodontosaurids remained extinct in the Campanian-Maastrichtian: Reassessment of a fragmentary maxilla from Presidente Prudente Formation, Brazil". Cretaceous Research. 84: 515–524. doi:10.1016/j.cretres.2017.09.008.
^Coria, R.A.; Currie, P.J. (2006). "A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina". Geodiversitas. 28 (1): 71–118.