DOI: 10.5327/Z2317-48892013000200006 Cretaceous chelonians from Marília Formation, Peirópolis, Minas Gerais, Bauru Basin, Brazil Quelônios do cretáceo da Formação Marília, Peirópolis, Minas Gerais, Bacia Bauru, Brasil Daniel Wagner Rogério1*, Ismar de Souza Carvalho2, Lucas del Mouro1 ABSTRACT: In the Upper Cretaceous deposits of Bauru Basin, the RESUMO: Nos depósitos do Cretáceo Superior da Bacia Bauru, são complete specimens of chelonians are rare. However, a large amount raros os espécimes completos de quelônios. No entanto, encontra-se of bone fragments of Pleurodyra suborder is found. In the paleon- uma grande quantidade de fragmentos ósseos da subordem Pleurodi- tological sites located at Peirópolis (Uberaba, Minas Gerais), which ra. Em afloramentos situados em Peirópolis (Uberaba, Minas Gerais), belong to Marília Formation (Maastrichtian – Campanian), there is pertencentes à Formação Marília (Maastrichtiano – Campaniano), one of the best fossil registers for this group in Brazil. The 315 skel- há um dos melhores registros fossíliferos para este grupo. As 315 peças etal remains collected in these outcrops and housed in the Complexo desarticuladas, coletadas nestes afloramentos, pertencentes à coleção Cultural e Científico de Peirópolis of Universidade Federal do Triân- do Complexo Cultural e Científico de Peirópolis da Universidade gulo Mineiro allow an assessment of the diversity and abundance of Federal do Triângulo Mineiro, possibilitam uma avaliação da di- Testudines during the Upper Cretaceous. A comparative analysis of versidade e da abundância destes animais durante o Neocretáceo. A these fossils with specimens from other localities from Bauru Basin análise comparativa destes fósseis com exemplares de outras localida- enabled a better understanding of the chelonians of the region in the des da Bacia Bauru possibilitou o melhor entendimento dos quelônios Cretaceous period. da região durante o Cretáceo. KEYWORDS: Bauru Basin; chelonians; Cretaceous. PALAVRAS-CHAVE: Bacia Bauru; quelônios; Cretáceo. INTRODUCTION Bauru Basin was originated in the Upper Cretaceous and extended through the Brazilian states of Mato Grosso In the Brazilian Upper Cretaceous, the fossiliferous do Sul, Goiás, Minas Gerais, São Paulo and Paraná occu- record of chelonian is concentrated in Adamantina and pies an area of approximately 350,000 km2 (Fig. 2). Its Marília Formations, both in the Bauru Basin. Seven spe- origin is related to the basaltic magmatism and tectonism cies are formally described in this basin (sensu Gaffney during the rupture of the gondwanic continent and ope- et al. 2011). In Triângulo Mineiro´s region, in the Marília ning of the South Atlantic Ocean (Fernandes & Coimbra Formation sediments, many fossil fragments that belong 2000). This basin has Santonian-Maastrichtian age, and to chelonian are found. These fossils are usually fragmen- elliptical shape with an elongated shaft in the NE direction ted and complete skeletons are rare, like the specimen (Dal Bó et al. 2009). MCT-1499-R (Fig. 1) housed in Departamento Nacional According to Dias-Brito et al. (2001), Bauru Basin ro- de Produção Mineral (DNPM) collection. There are few cks comprise a set dominated by sandstones, siltstones, studies about these fossils, which make the analysis of this and mudstones/shales, which were accumulated in seve- material important for understanding the chelonian diver- ral depositional systems ranging from alluvial, aeolian, sity from Marília Formation. fluvial, and lacustrine. It is divided into two major units: 1Programa de Pós-Graduação em Geologia, Instituto de Geociências da Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro (RJ), Brasil. E-mail: [email protected], [email protected] 2Instituto de Geociências, Departamento de Geologia da Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro (RJ), Brasil. E-mail: [email protected] *Corresponding author Manuscrito ID 27923. Recebido em: 02/07/2012. Aprovado em: 18/04/2013 273 Brazilian Journal of Geology, 43(2): 273-284, June 2013 Cretaceous chelonians from Marília Formation, Brazil & Suguio 1987). This unit was divided in three members: Ponte Alta, Serra da Galga, and Echaporã. The Ponte Alta Member is found predominantly at Triângulo Mineiro region and it is the basal portion of Marília Formation (Ribeiro 2001). The Echaporã Member occurs at the top edge of the basin, being more significant in the region of Marília, Echaporã, and Monte Alto, in São Paulo State. The Serra da Galga Member oc- curs only at Triângulo Mineiro region, and concentrates the most important fossiliferous sites of large vertebrates in the Bauru Basin. FOSSIL CHELONIANS OF BAURU BASIN The Bauru Basin presents a very diversified fauna of fos- sil reptile (Bertini 1994, Carvalho 2000). Many chelonian fossils are found in its sediments and so far seven species 10 cm closely related and included in the family Podocnemididae Figure 1. Chelonian carapace (MCT 1499-R) from were described, as seen in Fig. 2 (Oliveira & Romano Peirópolis and housed at Departamento Nacional de 2007, Gaffney et al. 2011). Produção Mineral (DNPM) collection. The first formal description of a chelonian from the Bauru Basin was “Podocnemis” harrisi Pacheco, 1913, from a location next to the municipality of Colina, São Paulo the Caiuá and Bauru Groups. The Caiuá Group happens State. Later, based on five photographs, a new species was in Paraná, São Paulo, and Mato Grosso do Sul, and also described in the São Paulo State, “Podocnemis” brasiliensis appearing in Northeastern Paraguay. This group is subdivi- Staesch, 1937 (Price 1953). ded in three formations: Rio Paraná, Goio Êre, and Santo Price (1953) examined the material described by Anastácio. There are fine to very fine sandstones interpre- Staesche (1937) and observed that the photographed ma- ted as sand sheets, wadis, and dunes. The Bauru Group terial and the one described as “Podocnemis” brasiliensis occurs mainly in Triângulo Mineiro region, in São Paulo were actually two distinct species. Thus, based on the ho- State and in the North of Paraná State. It is divided into lotype of “Podocnemis” brasiliensis, a new species was des- Adamantina, Uberaba, and Marília formations. It is obser- cribed, Roxochelys wandeleyi Price, 1953. Furthermore, ved in this group the presence of conglomerates, mudsto- Broin (1988) and Kischlat (1994) noticed a similarity nes, and siltstones interpreted as alluvial fan systems, flu- grouping “Podocnemis” harrisi and Roxochelys wanderleyi in vial and swamps (Fernandes & Coimbra 2000). a single genus, Roxochelys. The fact that the holotype of Reptile fossils (crocodylomorpha, chelonian, and di- “Podocnemis” harrisi was lost precludes any confirmation. nosaurs), fish, anuran, mollusks, crustaceans and plants, Then, “Podocnemis” harrisi should be considered as nomi- as well as vertebrate and invertebrate ichnofossils (Dias- na dubia (Kischlat et al. 1994, Oliveira & Romano 2007). Brito et al. 2001, Carvalho 2000) are found in Bauru A fourth species found among the cities of Presidente Basin. In Marília Formation, at Triângulo Mineiro region, Prudente and Pirapózinho, in São Paulo State, was descri- are found the chelonian fossils analyzed here. Dias-Brito bed by Suárez (1969), Podocnemis elegans. This species was et al. (2001) suggested Neo-Maastrichtian age to the sedi- first assigned to the genus Roxochelys (Broin 1971); but la- ments in Marília Formation. This formation is extended ter Kischlat and Azevedo (1991) concluded that it could through Goiás and São Paulo states and Triângulo Mineiro not be assigned to this genus. Kischlat (1994) proposed Region in Minas Gerais State. Its sediments consist of fine a new genus: Bauruemys, in which Podocnemis elegans to medium sandstones intercalated with conglomeratic le- and Podocnemis brasiliensis were included. Kischlat (1994) and vels (Fúlfaro & Barcelos 1991). The depositional system Kischlat et al. (1994) indicated that there are no morpholo- would be a combination of alluvial fans reworked by a gical features to add “Podocnemis” harrisi and “Podocnemis” braided fluvial system, with lacustrine limestones (Barcelos brasiliensis in the genus Podocnemis. Therefore, these 274 Brazilian Journal of Geology, 43(2): 273-284, June 2013 Daniel Wagner Rogério et al. 50° 54° 52° GO 18° MG Peirópolis 20° "Podocnemis" brasiliensis Colina Roxochelys wanderleyi Cambaremys langertoni Pricemys calera Peiropemys mezzalirai MS SP Araçatuba "Podocnemis" harrisi Bauruemys elegans Pirapózinho 22° Rio Ivaí PR 0 50 100m Bauru Group Marília Formation Uberaba Formation Adamantina Formation Caiuá Group Santo Anastácio Formation Rio Paraná Formation Goio Erê Formation Figure 2. Map indicating the location of Bauru Basin, where the formation of Bauru Group and Caiuá Groups emerge, emphasizing the place of the chelonian species described to the basin (based on Fernandes 2004). species correspond respectively to Roxochelys harrisi and Basin. These fossils are housed at Complexo Cultural Bauruemys brasiliensis. e Científico de Peirópolis of Universidade Federal do França and Langer (2005) designated a new species Triângulo Mineiro (CCCP/UFTM) collection. All spe- from Peirópolis locality, at Uberaba city in Minas Gerais, cimens have already been prepared and are well-preser- which was named Cambaremys langertoni. However, they ved, although most of them are not articulated. There stated that this could represent a juvenile individual of are stratigraphic controls of all materials deposited in Bauruemys brasiliensis.