Carcharodontosauridae Explained

Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, carcharodontósauros: "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. 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 NaNMT for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500kg (1,100lb).

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).[1] 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.[2] [3] While some teeth and a maxilla discovered in Maastrichtian deposits of Brazil.[4] [5] this identification has been subsequently rejected and the material assigned to abelisaurids after better examination,[6] and there are no reliable records of carcharodontosaurs in South America beyond the end of the Turonian. In December 2011, Oliver W. M. Rauhut described a new genus and species of carcharodontosaurid from the Late Jurassic (late Kimmeridgian to earliest Tithonian faunal stage, about 154-150 million years ago) of Tendaguru Formation, southeastern Tanzania. This genus, Veterupristisaurus represents the oldest known carcharodontosaurid.[7]

Classification

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.[8] [9] 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.[10] In 1998 Paul Sereno defined Carcharodontosauridae as a clade, consisting of Carcharodontosaurus and all species closer to it than to either Allosaurus, Sinraptor, Monolophosaurus, or Cryolophosaurus. Therefore, this clade is by definition outside of the clade Allosauridae.

The cladogram below follows the analyses by Canale et al. (2022) from their description of the large carcharodontosaurine Meraxes..[11]

In his 2024 review of theropod relationships, Cau recovered the following results for the Carcharodontosauridae.

Bahariasaurus has also been proposed as a carcharodontosaurid, but its remains are too fragmentary to be certain.[12]

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.

Paleobiology

Growth

Studies of the Argentinian taxon Meraxes suggest that these allosauroids were slow-growing, taking as long as 30-40 years to reach maturity. The maximum age for the holotype specimen was estimated to be roughly 50 years at the time of its death, making it the oldest known non-avian theropod. Unlike Tyrannosaurus, to which its growth has been compared, this carcharodontosaurid kept growing throughout its life.[13]

External links

Notes and References

  1. Brusatte . S. . Benson . R. . Chure . D. . Xu . X. . Sullivan . C. . Hone . D. . 2009 . The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids . Naturwissenschaften . 96. 9. 1051–8. 10.1007/s00114-009-0565-2 . 19488730 . 2009NW.....96.1051B . 20.500.11820/33528c2e-0c9c-4160-8693-984f077ee5d0 . 25532873 . free .
  2. 2021-09-01. Testing the persistence of Carcharodontosauridae (Theropoda) in the Upper Cretaceous of Patagonia based on dental evidence. Cretaceous Research. en. 125. 104875. 10.1016/j.cretres.2021.104875. 0195-6671. Meso. J.G.. Juárez Valieri. R.D.. Porfiri. J.D.. Correa. S.A.S.. Martinelli. A.G.. Casal. G.A.. Canudo. J.I.. Poblete. F.. Dos Santos. D.. 11336/183886 . free.
  3. Novas, de Valais, Vickers-Rich, and Rich. (2005). "A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids." Naturwissenschaften,
  4. Rodrigo P. Fernandes de Azevedo . Felipe Medeiros Simbras . Miguel Rodrigues Furtado . Carlos Roberto A. Candeiro . Lílian Paglarelli Bergqvist . amp. 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 . 10.1016/j.cretres.2012.06.004.
  5. 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 . . 42 . 2 . 323–330 . 10.5327/z0375-75362012000200008 . 2024-05-08 . free .
  6. Delcourt . R. . Grillo . O.N. . Carcharodontosaurids remained extinct in the Campanian-Maastrichtian: Reassessment of a fragmentary maxilla from Presidente Prudente Formation, Brazil . Cretaceous Research . 84 . 515–524 . 2017 . 10.1016/j.cretres.2017.09.008 .
  7. Rauhut . Oliver W. M. . 2011 . Theropod dinosaurs from the Late Jurassic of Tendaguru (Tanzania) . Special Papers in Palaeontology . 86 . 195–239 .
  8. Ortega . F. . Escaso . F. . Sanz . J. L. . 2010 . A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain . Nature . 467 . 7312 . 203–206 . 10.1038/nature09181 . 20829793 . 2010Natur.467..203O . 4395795 . 2016-12-06 . 2018-10-08 . https://web.archive.org/web/20181008145947/http://pagina.jccm.es/museociencias/Ortega_etal_2010_Tero_Concavenator_Ki_Cuenca_esp_nature09181.pdf . dead .
  9. Eddy . DR . Clarke . JA . 2011 . New Information on the Cranial Anatomy of Acrocanthosaurus atokensis and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda) . PLOS ONE . 6 . 3 . e17932 . 10.1371/journal.pone.0017932 . 21445312 . 3061882. 2011PLoSO...617932E . free .
  10. Coria . R.A. . Currie . P.J. . 2006 . A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina . Geodiversitas . 28 . 1. 71–118 .
  11. Canale. J.I. . Apesteguía. S. . Gallina. P.A. . Mitchell. J. . Smith. N.D. . Cullen. T.M. . Shinya. A. . Haluza. A. . Gianechini. F.A. . Makovicky. P.J.. New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction. Current Biology . 10.1016/j.cub.2022.05.057. 2022-07-07 . 32 . 14 . 3195–3202.e5 . 35803271 . free.
  12. Rauhut, (1995). "Zur systematischen Stellung der afrikanischen Theropoden Carcharodontosaurus Stromer 1931 und Bahariasaurus Stromer 1934." Berliner geowissenschaftliche Abhandlungen, E16 (Gundolf-Ernst-Festschrift): 357-375.
  13. Web site: T. rex had huge growth spurts, but other dinos grew slow and steady: By cutting into fossils and examining growth rings, scientists learned how predatory dinosaurs got so big. ScienceDaily.