Geobios3 9( 2006)3 19#327 http://france.elsevier.com/direct/GEOBIO/ Original article Vertebrate fossils from the Adamantina Formation (Late Cretaceous), Prata p aleontological district, Minas Gerais State, Brazil Vertébrés fossiles du Crétacé supérieur de la Formation Adamantina, district p aléontologique de Prata, État de Minas Gerais, Brésil Vertebrados fósseis da Formação Adamantina (Neocretáceo) do Distrito Paleontológico do Prata, Estado de Minas Gerais, Brasil Carlos Roberto A . Candeiro a,b,*, Adriano R. Santos a, Thomas H. Rich c,d, Thiago S. Marinho a,b, Emerson C. Oliveira a aMuseu de minerais e rochas, Universidadef ederal de uberlândia (UFU), Avenida J oão N aves de Á vila 2160, 38408-100 Uberlândia, MG, B razil bLaboratório de macrofósseis, departamento de g eologia, Universidadef ederal do Rio de Janeiro (UFRJ), avenida B rigadeiro Trompowski, s /n, I lha do Fundão, 21949-900 Rio de Janeiro, RJ, B razil cMuseum of Victoria, P O Box 666E, M elbourne, Victoria, A ustralia dSchool of geosciences, P O Box 28E, monash University, Victoria 3800, A ustralia Received 11May 2004; accepted 21 October 2004 Available online 22 May 2006 Abstract In this contribution is given a p reliminary u p-to-date annotated list of all fossil vertebrates from the Turonian#Santonian Adamantina Forma- tion, Bauru Group where it occurs in the Prata p aleontological district which is located 45 km to the west of Prata in Minas Gerais State, Brazil. The A damantina Formation is a reddish sandstone in the Triângulo Mineiro region. These fluviolacustrine sediments were deposited in a semiarid environment. Three fossil vertebrate sites occur in the Prata p aleontological district. The diversity of vertebrates in the Adamantina Formation is modest, and its components comprise a mixture of typical austral Gondwana t axa (such as abelisaurids, A eolosaurus) and b oreal Gondwana taxa (such as Carcharodontosauridae). The absence of Laurasian taxa in the u pper p art of the Bauru Group is noteworthy. Excepting some turtles, crocodylians, and one titanosaurid, most of the specimens discovered in this Group are b ased on fragmentary and isolated remains, which make it difficult to correctly identify the fossils. For this reason, many of the t axa have only b een identified in a p reliminary manner. Despite this drawback, the dinosaurs are typical Gondwana forms with no evidence of Laurasian affinities. This is concordant with the idea that the Laurasian dinosaurs entered South America at the end of the Late Cretaceous; i.e. after the Turonian#Santonian, the age of the A damantina Formation. ©2006 Elsevier SAS. All r ights reserved. Résumé La liste des v ertébrés fossiles est mise j our dans la Formation Adamantina datée du Turonien-Santonien affleurant dans le district p aléonto- logique de Prata 45 km l$est de Prata (Minas Gerais, Brésil). La Formation A damantina est composée de grès rougeâtres dans la région du Triangle Minier. Les sédiments fluviolacustres se sont déposés dans u n environnement semi-aride. Trois sites vertébrés fossiles sont connus dans le district p aléontologique de Prata. La diversité des vertébrés de la Formation A damantina est réduite et comprend u n mélange de taxons typiques du Gondwana austral (comme des Abelisauridés, A eolosaurus) et des taxons du Gondwana b oréal (comme des Carcharodontosauridae). * Corresponding author. E-mail address: [email protected]à à (C.R.A.à Candeiro). 0016-6995/$ - see front matter ©2006 Elsevier SAS. All rights r eserved. à doi:10.1016/j.geobios.2005.10.003 320 C.R.A. Candeiro et al. / Geobios 39 (2006) 319#327 L$absence de t axons laurasiatiques dans la p artie supérieure du Groupe Bauru est r emarquable. Excepté quelques tortues, des crocodiliens et u n titanosauridé, la plupart des spécimens découverts dans ce Groupe Bauru sont r eprésentés par des restes fragmentaires et isolés. Pour cette raison, seules des identifications p réliminaires sont p roposées. Toutefois, les dinosaures sont typiques du Gondwana sans évidence d$affinité Laura- sienne. Ceci est en accord avec l$hypothèse que les dinosaures laurasiens ne seraient arrivés en Amérique du Sud qu$à la fin de Crétacé supérieur, c$est-à-dire après le Turonien-Santonien, âge de la Formation A damantina. ©2006 Elsevier SAS. All r ights reserved. Resumo Na presente contribuição é apresentada uma listagem p reliminar de todos os fósseis de vertebrados do Distrito Paleontológico do Prata (For- mação Adamantina, Turoniano-Santoniano, Grupo Bauru). As rochas da Formação Adamantina são compostas por arenitos avermelhados que afloram na região do Triângulo Mineiro. Esses sedimetnos de origem fluvio-lacustre foram depositados em u m ambiente semi-árido. São conhe- cidos três sítios de vertebrados fósseis que ocorrem no Distrito Paleontológico do Prata. A diversidade de v ertebrados na Formação Adamantina é modesta sendo representados por uma mistura típica de taxa austrais do Gondwana (abelisaurídeos e A eolosaurus) e boreais (carcarodotontosau- rídeos). A ausência de taxa laurasianos na p arte superior do Grupo Bauru é notável. Exceto p ela presença de tartarugas, crocodilianos e u m titanossaurídeo a maioria dos espécimes descobertos nessa unidade geológica é baseada em restos fragmentários e isolados os quais são de difícil identificação. Por essa razão, a maioria desses taxa têm sido somente identificados de forma p reliminar. Considerando essa desvantagem, se p ode afirmar que os dinossauros do Prata são tipicamente de formas gondwânicas com nenhuma evidência de formas laurasianas. Isso é concordante com a idéia de que os dinossauros laurasianos entraram n a América do Sul somente no final do N eocretáceo, ex. depois do Turoniano-Santo- niano, que é a idade da Formação Adamantina. ©2006 Elsevier SAS. All r ights reserved. Keywords: Late Cretaceous; Brazil; Crocodiles; Dinosaurs; Turtles Mots clés :Crétacé supérieur ; Brésil ; Crocodiliens ; Dinosaures ; Tortues Palabras-chaves: N eocretáceo; Brasil; Crocodilos; Dinossauros; Tartarugas 1. Introduction Since the b eginning of the last century, numerous specimens of fossil vertebrates have b een collected from continental Cre- taceous r ocks of the Adamantina Formation, Bauru Group, in the Bauru Basin, Triângulo Mineiro region, Minas Gerais State. In the same area of Minas Gerais State, the Marília For- mation (Ponte Alta and Serra da Galga Members) also has yielded fossil vertebrates. Both formations have produced fau- nas consisting p rimarily of fishes, turtles, crocodylians, and di- nosaurs. All of these fossils occur in sandstones deposited in braided river channels. A large quantity of fossil bones has b een found in the con- tinental Cretaceous rocks exposed in the Prata p aleontological district of the Triângulo Mineiro region of Minas Gerais State, Brazil (Fig. 1; Goldberg et al., 1995a, 1995b; Silva et al., 2001; Marinho, 2003; Candeiro et al., 2003; Marinho et al., 2003). For this reason, the Prata p aleontological district, located 45 km w est of the town of Prata, is k nown as one of the most important fossil locations, as it contains abundant remains of sauropod and theropod dinosaurs as w ell crocodylians and tur- tles. Many authors (Soares et al., 1980; Suguio and Barcelos, 1983; Barcelos, 1984; Candeiro, 2002) assign the sediments of Prata p aleontological district to the Adamantina Formation (Bauru Group), which was dated as Turonian#Santonian in age (Dias-Brito et al., 2001). This u nit is exposed at the Serra da Boa Vista Hill, in the vicinity of Prata. Some of the richest Cretaceous fossil vertebrate localities in Central Brazil occur in the Adamantina Formation. Many of the Adamantina Formation sites in the Prata p aleontological district have b een k nown since the 1920s (Price, 1961). Owing to a lack of reliable lithological and p aleontological data, the geological ages of these sites are not w ell established. The Adamantina Formation was formally proposed b y Soares et al. (1980). The u nit, 2#20 m t hick, consists of r ose to b rown fine grained, cross-bedded sandstone. The type sec- tion of this formation was in the town of Adamantina, São Paulo State. In Triângulo Mineiro, the A damantina Formation is the b asal lithostratigrafic u nit of the Bauru Group and is widely exposed in the area. In the Prata p aleontological district, Triângulo Mineiro (Fig. 1), three fossil vertebrate sites occur in the Adamantina Formation. These three fossil sites represent the b est record of Late Cretaceous vertebrates in the Minas Gerais State (Brazil). This makes those sites some of the most important w hen dis- cussing the fossil r ecord of Late Cretaceous in Minas Gerais State. The vertebrates reported here are from the A damantina Formation near Prata, and b elong to the following groups: abe- lisaurs, carcharodontosaurs, A eolosaurus, and titanosaur dino- saurs, turtles, and crocodylians. More is known about the dino- saurs than any other group from the Prata p aleontological district. The p aleontologist Llewellyn Ivor Price first reported to the Departamento Nacional de Produção Mineral fragmen- tary dinosaur b ones in 1940. The fossils were transferred to Rio de Janeiro (Price, 1961). Since then, there have b een nu- merous fossil collecting trips to the Prata p aleontological dis- trict that have yielded new dinosaurs and other v ertebrate fos- sils (Silva et al., 2001). However, detailed stratigraphic studies based on dinosaur remains were not attempted. C.R.A. Candeiro et al. / Geobios 39 (2006) 319#327 321 Fig. 1. Location of the Prata p aleontological district, and geographic distribution of the Cretaceous fossiliferous location. 2. Geological setting The Adamantina Formation was defined b y Soares et al. (1980) and is known in the following states of Southeast Brazil: Goiás, Mato Grosso do Sul, Minas Gerais and São Paulo. These authors regarded it as p art of the Bauru Group, which occurs in the Paraná Basin.