Abstract
Although the Late Jurassic of Portugal has provided abundant dinosaur fossils, material from the Early Cretaceous is scarce. This paper reports new cranial and postcranial material of the theropod dinosaur Baryonyx walkeri found in the Barremian (Papo Seco Formation) of Portugal. This specimen, found at Praia das Aguncheiras, Cabo Espichel, consists of a partial dentary, isolated teeth, pedal ungual, two calcanea, presacral and caudal vertebrae, fragmentary pubis, scapula, and rib fragments. It represents the most complete spinosaurid yet discovered in the Iberian Peninsula and the most complete dinosaur from the Early Cretaceous of Portugal. This specimen is confidently identified as a member of Baryonychinae due to the presence of conical teeth with flutes and denticles in a dentary rosette. The specimen ML1190 shares the following characteristics with Baryonyx walkeri: enamel surface with small (nearly vertical) wrinkles, variable denticle size along the carinae, 6–7 denticles per mm, wrinkles forming a 45 degree angle near the carinae, and tooth root longer than crown. In addition, dubious taxa based on teeth morphology such as Suchosaurus cultridens (Owen, 1840–1845), and Suchosaurus girardi (Sauvage 1897–98; Antunes & Mateus 2003) are discussed, based on comparisons with well-known material such as Baryonyx walkeri Charig & Milner, 1986. Suchosaurus cultridens and S. girardi are considered as nomina dubia due to the lack of diagnostic apomorphies, but both specimens are referred to Baryonychinae incertae sedis.References
Antunes, M.T. & Mateus, O. (2003) Dinosaurs of Portugal. Comptes Rendus Palevol, 2, 77–95.
Barrett, P., Benson, R., Rich, T. & Vickers-Rich, P. (2010) A definitive spinosaurid theropod from the Lower Cretaceous of Australia and its implications for Gondwanan paleobiogeography. Society of Vertebrate Paleontology, Program and Abstracts, 57A.
Benson, R.B.J. (2010) A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnean Society, 158, 882–935.
Brochu, C. (1996) Closure of neurocentral sutures during crocodilian ontogeny: implications for maturity assessment in fossil archosaurs. Journal of Vertebrate Paleontology, 16, 49–62.
Brusatte, S.L, Benson, R.B.J., Carr, T.D., Williamson, T.E. & Sereno, P.C. (2007) The systematic utility of theropod enamel wrinkles. Journal of Vertebrate Paleontology, 27, 1052–1056.
Buffetaut, E. (2007) The spinosaurid dinosaur Baryonyx (Saurischia, Theropoda) in the Early Cretaceous of Portugal. Geological Magazine, 144, 1021–1025.
Buffetaut, E. & Ouaja, M. (2002) A new specimen of Spinosaurus (Dinosauria, Theropoda) from the Lower Cretaceous of Tunisia, with remarks on the evolutionary history of the Spinosauridae. Bulletin de la Société Geologique de France, 173, 415–421.
Buffetaut, E. & Ingevat, R. (1986) Unusual theropod dinosaur teeth from the Upper Jurassic of Phu Wiang, northeastern Thailand. Revue de Paléobiologie, 5, 217–220.
Buffetaut, E., Suteethorn, V., Tong, H. & Amiot, R. (2008) An Early Cretaceous spinosaurid theropod from southern China. Geological Magazine, 145, 745–748.
Canudo, J.I. (2006) La ambiguedad paleobiogeografica de los dinosaurios ibericos durante el Cretacico Inferior. Actas de las III Jornadas Internacionales sobre Paleontologia de Dinosaurios y su Entorno, 21–45.
Carrano, M.T. (2007) The appendicular skeleton of Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the Late Cretaceous of Madagascar. Journal of Vertebrate Paleontology, 27 (suppl. to 2), 163–179.
Charig, A.J. & Milner, A.C. (1986) Baryonyx, a remarkable new theropod dinosaur. Nature, 324, 359–361.
Charig, A.J. & Milner, A.C. (1997) Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Bulletin of the Natural History Museum of London (Geology), 53, 11–70.
Choffat, P. (1904–1907) Le Crétacique dans l'Árrabida et dans la contrée d´Ericeira. Comunicações da Comissão do Serviço Geológico de Portugal, 6, 1–51.
Dinis, J.L., Rey, J., Cunha, P.P., Callapez, P. & Reis, R.P.D. (2008) Stratigraphy and allogenic controls of the western Portugal Cretaceous: an updated synthesis. Cretaceous Research, 29, 772–780.
Ferreira, O.V. (1961) Fauna ictyológica do Cretácico de Portugal. Comunicações dos Serviços Geológicos de Portugal, 45, 249–278.
Fowler, D. (2007) Recently rediscovered baryonychine teeth (Dinosauria: Theropoda): new morphologic data, range extension and similarity to ceratosaurs. Journal of Vertebrate Paleontology, 27 (suppl. to 3.), 76A.
Gauthier, J.A. (1986) Saurischian monophyly and the origin of birds. Memoirs of the California Academy of Sciences, 8, 1–55.
Gilmore, C.W. (1920) Osteology of the Carnivorous dinosauria in the United States National Museum, with special reference to the genera Antrodemus (Allosaurus) and Ceratosaurus. United States National Museum, Bulletin, 110, 1–154.
Heinrich, W.-D. (1999) The taphonomy of dinosaurs from the Upper Jurassic of Tendaguru (Tanzania) based on field sketches of the German Tendaguru Expedition (1909–13). Mitteilungen aus dem Museum für Naturkunde Berlin, Geowissenschaftliche Reihe, 2, 25–61.
Kullberg, J.C., Rocha, R.B., Soares, A.F., Rey, J., Terrinha, P., Azerêdo, A.C., Callapez, P., Duarte, L.V., Kullberg, M.C., Martins, L., Miranda, J.R., Alves, C., Mata, J., Madeira, J., Mateus, O., Moreira, M. & Nogueira, C.R. (in press) A Bacia Lusitaniana: Estratigrafia, Paleogeografia e Tectónica. In: Geologia de Portugal no contexto da Ibéria. Escolar Editora. Lisboa.
Liñán, C.C. (2001) Mapa geológico de la Península Ibérica, Baleares Y Canarias. Escala 1:1.000.000. Instituto Tecnológico de España. [geological map, not paginated]
Lydekker, R. (1888) Catalogue of the fossil Reptilia and Amphibia in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. British Museum (Natural History), London, 309 pp.
Machado, E.B. & Kellner, A.W.A. (2005) Notas sobre Spinosauridae (Theropoda, Dinosauria). Anuário do Instituto de Geociências – UFRJ, 28, 158–173.
Madsen, J.H. (1976) Allosaurus fragilis: a revised osteology. Utah Geological Survey Bulletin, 109, 1–163.
Manuppella, G. (coord.) (1994) Carta Geológica de Portugal à escala 1:50 000, Folha 38-B. Setúbal. Instituto Geológico e Mineiro, Portugal. [geological map, not paginated]
Marsh, O.C. (1881) Principal characters of American Jurassic dinosaurs. Part V. The American Journal of Science and Arts, 3, 417–423.
Martill, D.M. & Hutt, S. (1996) Possible baryonychid dinosaur teeth from the Wessex Formation (Lower Cretaceous, Barremian) of the Isle of Wight, England. Proceedings of the Geologists' Association, 107, 81–84.
Martill, D.M., Cruickshank, A.R.I., Frey, E., Small, P.G. & Clarke, M. (1996) A new crested maniraptoran dinosaur from the Santana Formation (Lower Cretaceous) of Brazil. Journal of the Geological Society, 153, 5–8.
Mateus, O. (1998) Lourinhanosaurus antunesi, a new Upper Jurassic allosauroid (Dinosauria: Theropoda) from Lourinhã (Portugal). Academia de Ciências. Memórias da Academia de Ciências de Lisboa, 37, 111–124.
Mateus, O. (2006) Late Jurassic dinosaurs from the Morrison Formation (USA), the Lourinhã and Alcobaça Formations (Portugal), and the Tendaguru beds (Tanzania): a comparison. New Mexico Museum of Natural History and Science Bulletin, 36, 223–231.
Mateus, O. & Antunes, M.T. (2000) Ceratosaurus sp. (Dinosauria: Theropoda) in the Late Jurassic of Portugal. In: 31st International Geological Congress (CD-Rom with abstracts). Rio de Janeiro, Brazil.
Mateus, O. & Antunes, M.T. (2003) A new dinosaur tracksite in the Lower Cretaceous of Portugal. Ciências da Terra (UNL), 15, 253–262.
Mateus, O. & Milàn, J. (2008) Ichnological evidence for giant ornithopod dinosaurs in the Upper Jurassic Lourinhã Formation, Portugal. Oryctos, 8, 47–52.
Milner, A.C. (2003) Fish-eating theropods: a short review of the systematics, biology and palaeobiogeography of spinosaurs. II Journadas Internacionales sobre paleontologiá de Dinosaurios y su Entoro, 129–138.
Norman, D.B. & Barrett, P.M. (2002) Ornithischian dinosaurs from the Lower Cretaceous (Berriasian) of England. Special Papers in Palaeontology, 68, 161–190.
Owen, R. (1840–1845) Odontography, or, a treatise on the comparative anatomy of the teeth. Hippolyte Bailliere, London, 655 pp.
Owen, R. (1842). Report on British fossil reptiles. Part II. Report of the British Association for the Advancement of Science for 1841, 11, 60–204.
Owen, R. (1878) Monograph of the fossil Reptilia of the Wealden and Purbeck Formations. Supplement VIII, (Goniopholis, Pterosuchus, and Suchosaurus). Palaeontographical Society Monographs, London, 1–15.
Rauhut, O.W.M. (2003) The interrelationships and evolution of basal theropod dinosaurs. Special Papers in Palaeontology, 69, 1–213.
Rayfield, E.J, Milner, A.C., Xuan, V.B. & Young, P.G. (2007) Functional morphology of spinosaur ‘crocodile-mimic’ dinosaurs. Journal of Vertebrate Paleontology, 27, 892–901.
Rey, J. (1972) Recherches geológiques sur le Crétacé inferieur de l'Estremadura (Portugal). Memórias dos Serviços Geológicos de Portugal, 21, 477 pp
Rey, J. (1992) Les unités lithostratigraphiques du Crétacé inférieur de la région de Lisbonne. Comunicações dos Serviços Geológicos de Portugal, 78, 103–124.
Rey, J., Graciansky, P.C. & Jacquin, T. (2003) Les séquences de dépôt dans le Crétacé inférieur du Bassin Lusitanien. Comunicações do Instituto Geológico e Mineiro, 90, 15–42.
Rey, J., Dinis, J.L., Callapez, P. & Cunha, P.P. (2006) Da rotura continental à margem passiva. Composição e evolução do Cretácico de Portugal. Cadernos de Geologia de Portugal, INETI, Lisbon, 75 pp.
Ricqlès, A. de, Mateus, O., Antunes, M.T. & Taquet, P. (2001) Histomorphogenesis of embryos of Upper Jurassic theropods from Lourinhã (Portugal). Comptes Rendus de l'Académie des Sciences-Series IIA - Earth and Planetary Science, 332, 647–656.
Ruiz-Omenãca, J.I., Canudo, J.I. & Cuenca-Bescós, G. (1998) Primera cita de dinosaurios barinonícidos (Saurischia: Theropoda) en el Barremiense superior (Cretácico Inferior) de Vallipón (Castellote, Teruel). Mas de las Matas, 17, 201–223.
Ruiz-Omenãca, J.I., Canudo, J.I., Cruzado-Cabalero, J.I., Infante, P. & Moreno-Azanza, M. (2005) Baryonychine teeth (Theropoda: Spinosauridae) from the Lower Cretaceous of La Cantalera (Josa, NE Spain). Darmstädter Beiträge zur Naturgeschichte, 14, 59–63.
Sauvage, H.E. (1897–98) Vertébrés fossiles du Portugal. Contribution à l’étude des poissons et des reptiles du Jurassique et du Crétacé. Direction Travaux. Géologique. Portugal, 1–47.
Sereno, P.C., Beck, A.L., Dutheil, D.B., Gado, B., Larsson, H.C.E., Lyon, G.H., Marcot, J.D., Rauhut, O.W.M., Sadleir, R.W., Sidor, C.A., Varricchio, D.J., Wilson, G.P. & Wilson, J.A. (1998) A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. Science, 282, 1298–1302.
Smith, J.B., Vann, D.R. & Dodson, P. (2005) Dental morphology and variation in theropod dinosaurs: implications for the taxonomic identification of isolated teeth. Anatomical Record, 285, 699–736.
Stromer, E. (1915) Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharîje-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen., nov. spec. Abhandlungen der Königlichen Bayerischen Akademie der Wissenshaften, mathematisch-physikalische Klasse, 28, 1–32.
Sues, H.-D., Frey, E., Martill, D.M. & Scott, D.M. (2002) Irritator challengeri, a spinosaurid (Dinosauria: Theropoda) from the Lower Cretaceous of Brazil. Journal of Vertebrate Paleontology, 22, 535–547.
Taquet, P. & Russell, D.A. (1998) New data on spinosaurid dinosaurs from the Early Cretaceous of the Sahara. Comptes Rendus de l’Academie des Sciences, Paris, Sciences de la terre et des planetes, 327, 347–353.
Ziegler, P.A. (1988) Evolution of the Arctic–North Atlantic and the western Tethys. American Association of Petroleum Geologists Memoir, 43, 1–198.