Anuário do Instituto de Geociências - UFRJ www.anuario.igeo.ufrj.br First Record of Sauropod Remains from the Maastrichtian Marília Formation (Bauru Group) of Monte Alegre de Minas since Friderich von Huene´s Description in 1931 Os Primeiros Registros de Saurópodes Provenientes do Maastrichtiano da Formação Marília (Grupo Bauru) de Monte Alegre de Minas desde a Descrição de Friderich von Huene em 1931 Carlos Roberto dos Anjos Candeiro1,2; Diego Sullivan de Jesus Alves3; Lívia Motta Gil2 & Silvia Fernanda de Mendonça Figueirôa4 1Universidade Federal de Goiás, Laboratório de Paleontologia e Evolução, Curso de Geologia, Campus Aparecida de Goiânia, Rua Mucuri, s/n, 74968-755, Área 03, St. Conde dos Arcos, Aparecida de Goiânia, GO, Brazil 2Universidade Federal de Goiás, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biodiversidade Animal, Alameda Palmeiras, s/n, 74710-310, Chácaras Califórnia, Goiânia, GO, Brazil 3Universidade Estadual de Campinas, Instituto de Geociências, Departamento de Geografia, Rua Carlos Gomes, 250, 13083-870, Cidade Universitária, Campinas, SP, Brazil 4Universidade Estadual de Campinas, Faculdade de Educação, Avenida Bertrand Russell, 801, 13083-870, Campinas, SP, Brazil E-mails: [email protected]; [email protected]; [email protected]; [email protected] Recebido em: 20/06/2018 Aprovado em: 16/10/2018 DOI: http://dx.doi.org/10.11137/2019_2_32_39 Abstract After 86 years since the historical work by von Huene describing dinosaur remains from the Marília Formation (Bauru Group) from the Monte Alegre de Minas municipality, new bone fragments from the same locality are presented here. The materials were identified as a part of a prezygapophysis and the margin of a robust bone. The fragmentary condition of these specimens did not allow a more specific assignment, but it was possible to identify characters that are present both in titanosaurids and sauropods. Keywords: Sauropod; Triângulo Mineiro region; Late Cretaceous Resumo Após 86 anos, do trabalho histórico de von Huene que descreveu restos de dinossauros da Formação Marília (Grupo Bauru) de município de Monte Alegre de Minas, aqui se reportam fragmentos de ossos tentativamente atribuí- dos como uma parte de pré-zigapófise e borda de um osso robusto. O estado muito fragmentário de preservação destes materiais dificulta uma atribuição mais específica, mas estes apresentam características respectivas de dinossauros titanosaurídeos e saurópodes. Palavras-chave: Saurópode; Região do Triângulo Mineiro; Neocretáceo Anuário do Instituto de Geociências - UFRJ 32 ISSN 0101-9759 e-ISSN 1982-3908 - Vol. 42 - 2 / 2019 p. 32-39 First Record of Sauropod Remains from the Maastrichtian Marília Formation (Bauru Group) of Monte Alegre de Minas since Friderich von Huene´s Description in 1931 Carlos Roberto dos Anjos Candeiro; Diego Sullivan de Jesus Alves; Lívia Motta Gil & Silvia Fernanda de Mendonça Figueirôa 1 Introduction were found in the municipality of Monte Alegre de Minas at the beginning of the last century. This re- The dinosaur remains from the Monte Alegre gion showed a great potential for the exploration of de Minas municipality were identified by Friderich limestone surface deposits and, until today, limes- von Huene in 1931 when he first discovered fossil tone mining operations are still active. von Huene remains in the rocks of the Maastrichtian of Marília (1931) has briefly mentioned the femur of a titano- Formation (Bauru Group) in the Triângulo Mineiro saur dinosaur found by the Comissão Geográfica e region (Fernandes & Coimbra, 1996). After a long Geológica de São Paulo (Geographic and Geologic period without new paleontological findings from Commission of São Paulo), however, the author does the same region, this contribution confirms the pa- not give a detailed description of the specimen. This leontological potential of these rocks as dinosaur material has been used as reference by many histo- remain-bearing levels. New field works were con- rical studies on fossils from the Bauru Group of the ducted in the same area where von Huene made his Triângulo Mineiro region (e.g., Kellner & Campos, findings, and two more specimens were discovered: 2000; Candeiro et al., 2004; Candeiro, 2005, 2007; the articular facet of a prezygapophysis and the mar- Peyerl et al., 2015). gin of an unidentified sinuous and robust bone. Al- though fragmentary, this new material adds, for the The first verified mention of fossil materials first time since 1931, new dinosaur specimens to the from the Late Cretaceous of the Triângulo Mineiro records of western Minas Gerais State. region was made by the paleontologist Frederich von Huene in 1931, who reported the herbivorous The goal of the present study is to describe titanosaurid dinosaur fossils found in the region and compare these two new dinosaur specimens. of Monte Alegre de Minas. During the 1940s and These findings add new dinosaur materials to the re- 1950s, many important studies (e.g., Price, 1945, cords of this region. 1950a, b, 1951, 1955) were published about the fos- sils from the Uberaba and the Marília formations. 1.1 Brief History of the Geology and These works comprise the most important systema- Paleontology of Monte Alegre de Minas tic studies about the reptile fauna from Peirópolis/ Uberaba, in the Triângulo Mineiro region. Titanosauria is the only sauropod clade with re- cords from the Bauru Group of Central Brazil. Many According to Figueirôa (1997), the first geo- isolated remains from the Triângulo Mineiro region logical surveys to the Triângulo Mineiro region were have been described thus far (e.g., von Huene, 1931; based on three main lines of action: territorial de- Kellner & Campos, 2000; Bertini et al., 2001; San- marcation, exploration of minerals for industrial use, tucci & Bertini, 2001; Almeida et al., 2004; Marinho and offering of general services. Moreover, impor- & Candeiro, 2005; Lopes & Buchmann, 2008; San- tant studies were made during this period in order to tucci, 2008; Candeiro, 2010; Bittencourt & Langer, delimit the frontiers between the states of São Paulo 2011). The following taxa have been formally des- and Minas Gerais. The southern border of the Triân- cribed to this geological unit: Maxakalisaurus topai gulo Mineiro region is limitrophe with the São Paulo Kellner, Campos, Azevedo, Trotta, Henriques, Graik State, and it was part of an important area of mineral & Silva 2006, from the Adamantina Formation of resources and of significant interest to the surveys the municipality of Prata; Baurutitan britoi Kellner, made by the Comissão Geográfica e Geológica de Campos & Trotta 2005; Trigonosaurus pricei Cam- São Paulo (Figueirôa, 1997; Candeiro et al., 2014). pos, Kellner, Bertini & Santucci 2005; and Ubera- batitan ribeiroi Salgado & Carvalho, 2008, from the Milward (1935) was the first to mention the Marília Formation of the municipality of Uberaba. great extension of the outcrops in the Triângulo Mi- neiro region. These outcrops are characterized by The first fossils from the Triângulo Mineiro elevated lowlands and steep slopes. The geological region described by Friedrich von Huene (1931) unit was formed by fluvial systems that eroded and Anuário do Instituto de Geociências - UFRJ ISSN 0101-9759 e-ISSN 1982-3908 - Vol. 42 - 2 / 2019 p. 32-39 33 First Record of Sauropod Remains from the Maastrichtian Marília Formation (Bauru Group) of Monte Alegre de Minas since Friderich von Huene´s Description in 1931 Carlos Roberto dos Anjos Candeiro; Diego Sullivan de Jesus Alves; Lívia Motta Gil & Silvia Fernanda de Mendonça Figueirôa exposed the outcrops throughout a large area across Echaporã members (Figure 1) (Barcelos, 1984). Ac- the geographical boundaries of the Triângulo Minei- cording to Batezelli et al. (2003), this geological unit ro region that are delimited by the rivers Rio Grande, is composed of calciferous sandstones (Ponte Alta Rio Paranaíba, and Rio Araguari. Member), conglomerates, conglomerate sandstones, claystones, and siltstones, associated with calcretes Hasui (1969) described the western portion and silcretes (Serra da Galga Member), as well as of the Marília Formation in the Triângulo Mineiro of sandstones and conglomerates cemented by cal- region where rocks composed of clay were predo- cium carbonate (Echaporã Member). The deposition minant, indicating the past occurrence of short pe- of the Marília Formation occurred by the association riods of erosive phases that could be interpreted as of alluvial fan, fluvial, and ephemeral lake systems alternate floods and sedimentation. This author was (Barcelos, 1984; Fernandes & Coimbra, 2000; Gol- the first to systematically describe the stratigraphic dberg & Garcia, 2000). Aeolian sand sheet deposits units that outcrop in the Triângulo Mineiro region, indicate the periodicity of the sedimentation episo- and characterized these rocks as the Bauru and Ube- des and soil development (Dal’ Bó, 2009; Basilici raba formations. et al., 2009), and the presence of an alluvial braided river (Batezelli & Ladeira, 2016). Dias-Brito et al. (2001) suggest that the Marília Formation is of Ma- 2 Geological Setting astrichtian age. The Marília Formation (Bauru Group) (Figure In this region, the Marília Formation outcrops 1) is subdivided in the Ponte Alta, Serra da Galga and reach 3 m in thickness (Figure 2) and are charac- Figure 1 Lithostratigraphic map of the Bauru Group (modified from Batezelli, 2015). Anuário do Instituto de Geociências - UFRJ 34 ISSN 0101-9759 e-ISSN 1982-3908 - Vol. 42 - 2