An Acad Bras Cienc (2021) 93(Suppl. 2): e20201557 DOI 10.1590/0001-3765202120201557 Anais da Academia Brasileira de Ciências | Annals of the Brazilian Academy of Sciences Printed ISSN 0001-3765 I Online ISSN 1678-2690 www.scielo.br/aabc | www.fb.com/aabcjournal PALEONTOLOGY The fi rst Jurassic theropod from the Running title: A Jurassic theropod Sergi Formation, Jatobá Basin, Brazil of Brazil KAMILA L.N. BANDEIRA, ARTHUR S. BRUM, RODRIGO V. PÊGAS, LUCY G. DE Academy Section: SOUZA, PAULO VICTOR LUIZ G.C. PEREIRA & ANDRÉ EDUARDO P. PINHEIRO PALEONTOLOGY Abstract: Archosaur osteological remains are abundant in Brazil, particularly from the Triassic and Cretaceous strata, but in Jurassic, the record is predominantly represented by ichnofossils. The Upper Jurassic archosaur records comprise the Paralligatoridae e20201557 Batrachomimus pastosbonensis, from the Pastos Bons Formation (Parnaíba Basin), remains of Mesoeucrocodylia from the Aliança Formation (Jatobá Basin), and fragments of Dinosauria from the Brejo Santo Formation (Araripe Basin) with a dubious assignment. 93 Here, we present the fi rst undoubted Dinosauria record for the Jurassic of Brazil, MCT (Suppl. 2) 2670-LE, a middle to distal caudal vertebra belonging to a theropod. MCT 2670-LE was 93(Suppl. 2) excavated in the 60s by prof. Ignacio Machado Brito, being primarily attributed to DOI strata of the Aliança Formation but the rock matrix involving the specimen allows us to 10.1590/0001-3765202120201557 correlate MCT 2670-LE to Sergi Formation, marking this specimen as the fi rst archosaur record of this unit. The caudal vertebra is assigned to Carcharodontosauria based on the hourglass shaped centrum and the deep and narrow ventral groove. The specimen provides new data to the paleogeographic distribution of carcharodontosaurians before the South America-Africa break-up, as well as understanding the theropod faunal turnover of paleoenvironments during the Jurassic-Cretaceous transition in Brazil. Key words: Theropoda, Carcharodontosauria, Caudal Vertebra, Upper Jurassic, Sergi For- mation, Jatobá Basin. INTRODUCTION & Langer 2011), due to the sedimentation and tectonic conditions unfavorable to the In Brazil, archosaur remains are well-known, preservation of bone elements (e.g., Milani 2007). especially those dating from the Mesozoic Era, This scenario makes challenging the study and the Triassic and Cretaceous deposits are the and the consequent interpretations of Jurassic main fossiliferous ones (Bittencourt & Langer fossil data on Brazil (e.g., Gallo & Brito 2004, 2011). The Cretaceous represents the most Gallo 2005, Bittencourt & Langer 2011). Thus, the expressive interval with abundant vertebrate Jurassic record for Brazil is best represented by fossil record (Bittencourt & Langer 2011, Brusatte the ichnofossils (e.g., Leonardi et al. 2007, but et al. 2017), both on the Lower (e.g, Pereira et al. see Table I), while the Araripe Basin (Brejo Santo 2020a, b) and Upper levels (e.g., Pinheiro et al. Formation and Missão Velha Formation), the 2018, Bandeira et al. 2019, Delcourt et al. 2020). Parnaíba Basin (Pastos Bons Formation) and Archosaurs are the predominant fossil records the Jatobá Basin (Aliança Formation), all from especially on the Upper Cretaceous strata Upper Jurassic, are the only units with tetrapod (Bandeira et al. 2018). However, rock exposures bone elements - mostly, archosaurs. The from the Brazilian Jurassic are scarce (Bittencourt Paralligatoridae Batrachomimus pastosbonensis An Acad Bras Cienc (2021) 93(Suppl. 2) KAMILA L.N. BANDEIRA et al. A JURASSIC THEROPOD OF BRAZIL Montefeltro et al. 2013, from the Pastos Bons 2670-LE is identified as a middle caudal vertebra Formation, is the only archosaur species of a carcharodontosaurian theropod. The new described so far for the Brazilian Jurassic specimen improves the understanding of the (Montefeltro et al. 2013). rare archorsaur remains from the Jurassic period Other records consist of small axial in Brazil. It is also possible to link MCT 2670-LE to elements (about 3-4 cm) found in the Brejo Santo theropods of other basins with Jurassic outcrops, Formation (Melo & Carvalho 2017), along with allowing an evaluation of the paleogeographic Mesoeucrocodylia teeth. These axial elements distribution of tetrapods recognized in these (which do not have a collection number) were formations, as well as the evolutionary and proposed as the first Dinosauria record for the faunal changes of paleoenvironments during Brazilian Jurassic (Melo & Carvalho 2017). However, the Jurassic-Cretaceous transition in Brazil. the authors provided no diagnostic feature for this classification, and the description of these elements is superficial. The specimen images HISTORICAL REMARKS also depict just a ventral view of the material, We describe a new fossil material collected close and more detailed comparisons become to the municipality of Petrolândia (Pernambuco) impossible. Due to the difficulty of knowing in 1962 by Prof. Dr Ignacio Machado Brito. the origin in which institution these specimens In the notes associated with the specimen, are allocated, as well as unclear diagnostic Brito mentioned that it was recovered in the characteristics that allow a more accurate margins of the São Francisco River upstream the systematic assignment, we assume here that the Petrolândia municipality. attribution to Dinosauria of these specimens This contribution is a tribute to Diogenes is doubtful. The Missão Velha Formation has de Almeida Campos, the paleontologist of the a rich fossil assemblage, including anurans, Museu de Ciências da Terra (Serviço Geológico do lizards, turtles, mesoeucrocodylians and even Brasil – CPRM), who had prof. Ignacio as advisor nonavian dinosaurs (sensu Brito et al. 1994), but and paleontology undergraduate professor. most elements require a formal description and Ignacio led Diogenes to his first collecting fossils systematic review. fieldwork at this same region. Besides this, Finally, for the Upper Jurassic of Aliança Diogenes made a prospect in the area in the Formation, there is a brief report of some 1980s aiming for the rescue of paleontological Mesoeucrocodylia remains (Silva et al. 2011) material prior to the construction of the Luis which are more recently reviewed and described Gonzaga hydroelectric plan. Therefore, the together with new mesoeucrocodylian findings material here described connects Diogenes with (Carvalho et al. 2021). Thus, we present the first his past advisor and to a region on which he had confirmed Dinosauria record for the Jurassic important historical action. of Brazil, MCT 2670-LE, collected in 1962 by prof. Ignacio Machado Brito at São Francisco riverbank (see Geological Settings). MCT An Acad Bras Cienc (2021) 93(Suppl. 2) e20201557 2 | 30 KAMILA L.N. BANDEIRA et al. A JURASSIC THEROPOD OF BRAZIL Table I. Jurassic sedimentary basins in Brazil, and their respective fossil contents, (when found). Abbreviations: Fm, Formation, Mb, Member. lithology geological distribution fossil record age references unit and depositional context Parecis Basin fine-grained to southeast of Schobbenhaus et aphanitic basalts, Rondônia (RO) to al. 1984, Marzoli et with subordinate Lower Jurassic - Fm. Anari the Northwest of no fossils related al. 1999, Silva et al. coarsed diabase Hettangian Mato Grosso (MT) 2003. Pedreira & bodies. Volcanic state Bahia 2004 flows similar to basalts from Schobbenhaus et comprises the Anari Formation, al. 1984, Marzoli et Fm Tapirapuã massif in Lower Jurassic - with columnar no fossils related al. 1999, Silva et al. Tapirapuã Mato Grosso (MT) Hettangian disjunction 2003. Pedreira & state and spheroidal Bahia 2004 exfoliation Outcrops in north reddish, friable of General Carneiro, and eolic in the valley of sandstones with Silva et al. 2003, Fm Rio Ávila the Culuene river no macrofossils related Jurassic rounded grains, Bahia, 2007 and northwest well to poorly of Vilhena, Mato selected Grosso (MT) state Outcrops in West of large scale cross- Rondônia (RO) and bedded bimodal no macrofossils or Pedreira & Bahia Fm. Botucatu small exposures in Jurassic sandstones. ichnofossils related 2000, 2004 southeast of Mato Aeolian dunes Grosso (MT) Parnaíba Basin arround the tholeiitic Schobbenhaus et municipality flood basalts, Lower–Middle al. 1984, Bellieni et Fm Mosquito of Fortaleza no macrofossils related interbedded with Jurassic al. 1992, Santos & dos Nogueiras, sandstones Carvalho 2004 Maranhão (MA) state Alparcata Basin for the base, se- ostracods; quences of conchostracans; siltstone, dark palynomorphs; shale, and occurs as a south- central belt in plant cuticles; Schobbenhaus et greenish and fishes Lepidotus( Upper Jurassic - Fm Pastos brownish mud- Maranhão (MA) al. 1984, Gallo, 2005, Bons state, with some piauhyensis, probable Oxfordian– Montefeltro et al. stones. The upper exposure in west of Semionotus and Kimmeridgian 2013 strata consist Piauí (PI) pleuropholids); of gray to green Crocodyliformes shales with wavy (i.e., Batrachomimus lamination pastosbonensis); An Acad Bras Cienc (2021) 93(Suppl. 2) e20201557 3 | 30 KAMILA L.N. BANDEIRA et al. A JURASSIC THEROPOD OF BRAZIL Table I. Continuation Paraná Basin widespread abundant ichnofossils: mostly composed occurrence in the as footprints and of fine-to Paraná Basin, which tracks produced cover great áreas by invertebrates Schobbenhaus et medium-grained of São Paulo (SP), (arachnids and insects) al. 1984, Scherer, quartz sandstones. Paraná (PR), Santa and tetrapods (small 2000, Friable, rounded Catarina