First report of a derived abelisaurid theropod from the Bajo de la Carpa Formation (Late Cretaceous), Patagonia, Argentina


Authors: Ezcurra MD, Méndez AH

Published in: Bulletin of Geosciences, volume 84, issue 3; pages: 547 - 554; Received 4 November 2008; Accepted in revised form 6 January 2009; Online 28 July 2009

Keywords: Theropoda, Abelisauroidea, Bajo de la Carpa Formation, Río Colorado Subgroup, Late Cretaceous, Argentina,

full text (PDF, 0.78 MB)

Export to RIS



An isolated anterior caudal vertebra of a medium-large sized theropod dinosaur is reported here. It comes from the Bajo de la Carpa Formation (Santonian, Late Cretaceous), Río Colorado Subgroup, Río Negro Province, northern Patagonia, Argentina. The specimen, MACN-PV-RN 1012, exhibits several derived characters that are diagnostic among theropods. Specifically, MACN-PV-RN 1012 is referable to Abelisauroidea because it possesses a centrodiapophyseal lamina on the ventral surface of the transverse processes, and to Abelisauridae due to the presence of transverse processes that are 1.4 times longer than the anteroposterior length of the centrum, a large median depression anterior to the base of the neural spine, and the lack of a prespinal fossa. MACN-PV-RN 1012 is included within Carnotaurinae, sharing with Carnotaurus and Aucasaurus transverse processes that are oriented dorsolaterally at an angle of 45° or more with regard to the horizontal axis of the vertebra. Thus, the specimen described here constitutes the first record of a derived abelisaurid from the Bajo de la Carpa Formation.


Accarie, H., Beaudoin, B., Dejax, J., Fries, G., Michard, J.-G. & Taquet, P. 1995. Découverte d’un dinosaure théropode nouveau (Genusaurus sisteronis n. g., n. sp.) dans l’albien marin de sisteron (Alpes de Haute-Provence, France) et extension au Crétacé inférieur de la lignée cératosaurienne. Comptes rendus de l’Académie de sciences 320, 327-334.

Allain, R. & Pereda Suberbiola, X. 2003. Dinosaurs of France. Comptes Rendus Palevol 2, 27-44.View article

Allain, R., Tykoski, R.S., Aquesbi, N., Jalil, N.-E., Monbaron, M., Russell, D. & Taquet, P. 2007. An abelisauroid (Dinosauria: Theropoda) from the Early Jurassic of the High Atlas Mountains, Morocco, and the radiation of ceratosaurs. Journal of Vertebrate Paleontology 27, 610-624.View article

Alvarenga, H.M.F. & Bonaparte, J.F. 1992. A new flightless land-bird from the Cretaceous of Patagonia. In Campbell, K.E. (ed.) Papers in Avian Paleontology. Natural History Museum of Los Angeles County, Science Series 36, 51-64.

Bonaparte, J.F. 1985. A horned Cretaceous carnosaur from Patagonia. National Geographic Research 1, 149-151.

Bonaparte, J.F. 1991a. The Gondwanian theropod families Abelisauridae and Noasauridae. Historical Biology 5, 1-25.View article

Bonaparte, J.F. 1991b. Los vertebrados fósiles de la Formación Río Colorado, de la Ciudad de Neuquén y cercanías, Cretácico superior, Argentina. Revista del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Paleontología 4(3), 17-123.

Bonaparte, J.F. 1996. Cretaceous tetrapods of Argentina. Münchner Geowissenschaftliche Abhandlungen A 30, 73-130.

Bonaparte, J.F. & Novas, F.E. 1985. Abelisaurus comahuensis, n. gen., n. sp., Carnosauria del Cretácico Tardío de Patagonia. Ameghiniana 21, 259-265.

Bonaparte, J.F., Novas, F.E. & Coria, R.A. 1990. Carnotaurus sastrei Bonaparte, the horned, lightly built carnosaur from the middle Cretaceous of Patagonia. Contributions in Science, Natural History Museum of Los Angeles County 416, 1-41.

Calvo, J.O., Rubilar-Rogers, D.&Moreno, K. 2004. A new Abelisauridae (Dinosauria: Theropoda) from northwest Patagonia. Ameghiniana 41, 555-564.

Canale, J.I., Scanferla, C.A., Agnolin, F.L. & Novas, F.E. 2008. New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods. Naturwissenschaften.View article

Carrano, M.T., Sampson, S.D. & Forster, C.A. 2002. The osteology of Masiakasaurus knopfleri, a small abelisauroid (Dinosauria: Theropoda) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology 22, 510-534.View article

Carrano, M.T. & Sampson, S.D. 2008. The phylogeny of Ceratosauria (Dinosauria: Theropoda). Journal of Systematic Palaeontology 6, 183-236.View article

Chiappe, L.M. & Calvo, J.O. 1994. Neuquenornis volans, a new Late Cretaceous bird (Enantiornithes: Avisauridae) from Patagonia, Argentina. Journal of Vertebrate Paleontology 14, 230-246.

Coria, R.A. 2001. New theropod from the Late Cretaceous of Patagonia, 3-9. In Tanke, D.H. & Carpenter, K. (eds) Mesozoic vertebrate life. Indiana University Press, Bloomington.

Coria, R.A., Chiappe, L.M.&Dingus, L. 2002.Anew close relative of Carnotaurus sastrei Bonaparte 1985 (Theropoda: Abelisauridae) from the Late Cretaceous of Patagonia. Journal of Vertebrate Paleontology 22, 460-465.View article

Coria, R.A., Currie, P.J. & Carabajal, A.P. 2006. A new abelisauroid theropod from Northwestern Patagonia. Canadian Journal of Earth Sciences 43, 1283-1289.View article

Coria, R.A. & Salgado, L. 2000. A basal Abelisauria, Novas 1992 (Theropoda-Ceratosauria) from the Cretaceous of Patagonia. Gaia 15, 89-102.

Currie, P.J. & Zhao, X. 1993. A new carnosaur (Dinosauria, Theropoda) from the Jurassic of Xinjiang, People’s Republic of China. Canadian Journal of Earth Sciences 30, 2037-2081.

Ezcurra, M.D. & Cuny, G. 2007. The coelophysoid Lophostropheus airelensis, nov. gen.: a review of the systematics of “Liliensternusairelensis from the Triassic-Jurassic outcrops of Normandy (France). Journal of Vertebrate Paleontology 27, 73-86.View article

Holtz, T.R. Jr. 1994. The phylogenetic position of the Tyrannosauridae: implications for theropod systematics. Journal of Paleontology 68, 1100-1117.

Huene, F. 1934. Ein neuer Coelurosaurier in der thuringischen Trias. Paläontologische Zeitschrift 16, 145-170.

Hugo, C.A.&Leanza, H.A. 2001. Hoja Geológica 3969-IV, General Roca, provincias del Neuquén y Río Negro. Instituto de Geología y Recursos Naturales, Segemar, Boletín 308, 1-71.

Juárez Valieri, R.D., Fiorelli, L.E. & Cruz, L.E. 2007. Quilmesaurus curriei Coria, 2001 (Dinosauria, Theropoda). Su validez taxonómica y relaciones filogenéticas. Revista del Museo Argentino de Ciencias Naturales, n.s. 9, 59-66.

Lamanna, M.C.,Martínez, R.D. & Smith, J.B. 2002. A definitive abelisaurid theropod dinosaur from the early Late Cretaceous of Patagonia. Journal of Vertebrate Paleontology 22, 58-69.View article

Leanza, H.A., Apesteguía, S., Novas, F.E. & De la Fuente, M.S. 2004. Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages. Cretaceous Research 25, 61-87.View article

Madsen, J.H. Jr. 1976. Allosaurus fragilis: a revised osteology. Utah Geological Survey Bulletin 109, 1-163.

Madsen, J.H. Jr. & Welles, S.P. 2000. Ceratosaurus (Dinosauria, Theropoda) a revised osteology. Utah Geological Survey Miscellaneous Publication 00-2, 1-80.

Martinelli, A.G. 2003. New cranial remains of the bizarre notosuchid Comahuesuchus brachybuccalis (Archosauria, Crocodyliformes) from the Late Cretaceous of Río Negro Province (Argentina). Ameghiniana 40, 559-572.

Martinelli, A.G. & Pais, D.F. 2008. A new baurusuchid crocodyliform (Archosauria) from the Late Cretaceous of Patagonia (Argentina). Comptes Rendus Palevol 7, 371-381.View article

Martinelli, A.G. & Vera, E.I. 2007. Achillesaurus manazzonei, a new alvarezsaurid theropod (Dinosauria) from the Late Cretaceous Bajo de la Carpa Formation, Río Negro Province, Argentina. Zootaxa 1582, 1-17.

Martínez, R., Giménez, O., Rodríguez, J. & Bochatey, G. 1986. Xenotarsosaurus bonapartei nov. gen. et sp. (Carnosauria, Abelisauridae), un nuevo Theropoda de la Formacion Bajo Barreal, Chubut, Argentina. Simposio de evolución de los vertebrados mesozoicos: IV Congreso Argentino de Paleontologia y Bioestratigrafía, 23-31.

Martínez, R., Novas, F.E. & Ambrosio, A. 2004. Abelisaurid remains (Theropoda, Ceratosauria) from Southern Patagonia. Ameghiniana 41, 577-585. O’Connor, P.M. 2007. The postcranial axial skeleton of Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar, 127-162. In Sampson, S.D. & Krause, D.W. (eds) Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar. Society of Vertebrate Paleontology Memoir 8.

Pol,D. 2005. Postcranial remains of Notosuchus terrestris Woodward (Archosauria: Crocodyliformes) from the Upper Cretaceous of Patagonia, Argentina. Ameghiniana 42, 21-38.

Porfiri, J.D, Calvo, J.O, Juárez-Valieri, R.D. & Santos, D.D. 2008. A new large theropod dinosaur from the Bajo de la Carpa Formation (Late Cretaceous) of Neuquén, Patagonia. III Congreso Latinoamericano de Paleontologia de Vertebrados, 202.

Rauhut, O.W.M. 2003. The interrelationships and evolution of basal theropod dinosaurs. Special Papers in Palaeontology 69, 1-214.

Rauhut, O.W.M. 2005. Post-cranial remains of ‘coelurosaurs’ (Dinosauria, Theropoda) from the Late Jurassic of Tanzania. Geological Magazine 142, 97-107.View article

Rauhut, O.W.M., Cladera, G., Vickers-Rich, P. & Rich, T.H. 2003. Dinosaur remains from the Lower Cretaceous of the Chubut Group, Argentina. Cretaceous Research 24, 487-497.View article

Sereno, P.C., Wilson, J.A. & Conrad, J.L. 2004. New dinosaurs link southern landmasses in the mid-Cretaceous. Proceedings of the Royal Society of London B, 1-6.

Sereno, P.C. & Brusatte, S.L. 2008. Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger. Acta Palaeontologica Polonica 53, 15-46.

Welles, S.P. 1984. Dilophosaurus wetherilli (Dinosauria, Theropoda): osteology and comparisons. Palaeontographica, Abteilung A 185, 85-180.

Woodward, A.S. 1896. On two Mesozoic crocodilians Notosuchus (genus novum) and Cynodontosuchus (genus novum) from the red sandstones of the territory of Neuquén (Argentina Republic). Annales del Museo de La Plata, Paleontologia 4, 1-20.

Woodward, A.S. 1901. On some extinct reptiles from Patagonia of the genera Miolania, Dinilysia and Genyodectes. Proceedings of the Zoological Society of London 1901, 169-184.

Zhao, X. & Currie, P.J. 1993. A large crested theropod from the Jurassic of Xinjiang, People’s Republic of China. Canadian Journal of Earth Sciences 30, 2027-2036.