See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/318348596 The Presence of Ankylosaur Tracks in the Guará Formation (Brazil) and Remarks on the Spatial and Temporal Distribution of... Article in Ichnos · July 2017 DOI: 10.1080/10420940.2017.1337573 CITATIONS READS 0 245 4 authors: Heitor Francischini Marcos André Fontenele Sales Universidade Federal do Rio Grande do Sul Universidade Federal do Rio Grande do Sul 25 PUBLICATIONS 33 CITATIONS 14 PUBLICATIONS 11 CITATIONS SEE PROFILE SEE PROFILE Cesar Leandro Schultz Paula Dentzien-Dias Universidade Federal do Rio Grande do Sul Universidade Federal do Rio Grande (FURG) 161 PUBLICATIONS 2,210 CITATIONS 34 PUBLICATIONS 191 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Maximizing constraints on the evolution of parasitism and complex life cycles in flatworms using µCT and trace fossils View project Recovery of continental tetrapod communities in Southwestern Pangaea following the Permo- Triassic mass extinction View project All content following this page was uploaded by Heitor Francischini on 12 October 2017. The user has requested enhancement of the downloaded file. ICHNOS https://doi.org/10.1080/10420940.2017.1337573 The Presence of Ankylosaur Tracks in the Guara Formation (Brazil) and Remarks on the Spatial and Temporal Distribution of Late Jurassic Dinosaurs Heitor Francischini a, Marcos A. F. Salesa, Paula Dentzien–Diasb, and Cesar L. Schultza aLaboratory of Vertebrate Paleontology, Institute of Geosciences, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; bLaboratory of Geology and Paleontology, Institute of Oceanography, Federal University of Rio Grande (FURG), Rio Grande, RS, Brazil ABSTRACT KEYWORDS The Guara Formation (Parana Basin, southern Brazil) is an Upper Jurassic unit that yielded a dinosaur Ankylosauria; South America; ichnoassemblage composed of theropod, ornithopod, and sauropod tracks. A new set of footprints Gondwana; Parana Basin; is described herein and its major features are heteropody, paraxony, and both manual and pedal Kimmeridgian–Tithonian tetradactyly, among others. Using ichnological, osteological, and stratigraphic approaches, we interpret these tracks as produced by an ankylosaur dinosaur. The record of these armored dinosaurs in South America is scarce and restricted to the Cretaceous units of Argentina, Bolivia, and Brazil. Therefore, the presence of these tracks in the Guara Formation provides the oldest evidence of ankylosaurs in western Gondwana and the first uncontroversial record of this group in Brazil. In addition, a comparison between the Guara Formation fossil record and other Kimmeridgian– Tithonian dinosaur-bearing units worldwide indicates that more efforts are needed to better understand the geographical distribution of Late Jurassic dinosaurs. Introduction The presence of Dinosauria in the Brazilian Mesozoic more recently reevaluated and their ornithischian nature has been noted since the second half of the 19th century was refuted (Machado and Kellner, 2007; Langer and (Allport, 1860; Marsh, 1869), and for a long time there Ferigolo, 2013). were only brief reports on occurrences of Triassic and By contrast, the dinosaur ichnological record is rela- Cretaceous units throughout the country (e.g., Mawson tively well-documented and includes theropod, sauro- and Woodward, 1907; Huene, 1942; Price, 1960, 1961; pod, and ornithischian tracks in almost all Brazilian among others). The first valid taxon from Brazil is basins (for a review, see Leonardi, 1994). Contrasting Staurikosaurus pricei (Colbert, 1970) from the Middle– with the record provided by the body remains, ornitho- Upper Triassic Santa Maria Supersequence, but since pod footprints are abundant in the Cretaceous of Brazil, then dozens of species were erected in the Brazilian terri- mainly in the Botucatu Formation of the Parana Basin tory, mainly from Lower and Upper Cretaceous units, and in the Antenor Navarro and Sousa formations of the such as the Santana and Bauru groups (Araripe and Par- Uirauna –Brejo das Freiras Basin (Leonardi, 1979; ana basins, respectively), besides several unnamed Leonardi and Spezzamonte, 1992; Carvalho, 1996, 2004; remains (for a review, see Bittencourt and Langer, 2011 Fernandes and Carvalho, 2007; Leonardi and Carvalho, and references therein). 2007; Leonardi et al., 2007). Additionally, ornithopod As noted in several reviews (e.g., Kellner, 1996; Kell- tracks also occur in the Guara Formation (Parana Basin), ner and Campos, 2000; Novas, 2007; Bittencourt and which has an ichnocoenosis composed of theropod, sau- Langer, 2011), the dinosaur osteological record in Brazil ropod, and ornithopod tracks corresponding to the only is composed mainly of Saurischia. Ornithischian remains dinosaur record from the Jurassic of Brazil (Dentzien– have not been recorded in any Mesozoic strata in Brazil, Dias et al., 2007, 2008, 2012; Francischini et al., 2015). despite the putative occurrences of the group in Triassic Therefore, when taken into account, the dinosaur ich- (Ferigolo and Langer, 2006) and Cretaceous (Leonardi nological record increases the spatial and temporal and Borgomanero, 1981) units. These materials were occurrences of the group in Brazil. Unfortunately, almost CONTACT Heitor Francischini [email protected] Laboratorio de Paleontologia de Vertebrados, Departamento de Paleontologia e Estratigrafia, Instituto de Geoci^encias, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves¸ 9500, Agronomia, Porto Alegre, 91501–970, Brazil. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/gich. © 2017 Taylor & Francis Group, LLC 2 H. FRANCISCHINI ET AL. all studies on the Brazilian Dinosauria ignore and/or paleodunes of the Botucatu Formation and the volcanic underestimate the trace fossil record. Filling in some deposits of the Serra Geral Group (Scherer and Lavina, gaps in this field, we herein describe a new trackway 2005; Milani et al., 2007). from the Upper Jurassic Guara Formation of southern `The Guara Formation is composed of fluvio-eolian Brazil. This discovery represents the first unambigu- rocks that crop out only in the southern margin of the ous thyreophoran record in the country, and these Parana Basin (Fig. 1), occurring in the southwestern tracks are morphologically similar to Metatetrapous region of the State of Rio Grande do Sul, southern Brazil valdensis from the Lower Cretaceous deposits of Ger- (Scherer et al., 2000; Scherer and Lavina, 2005, 2006) many. In order to associate the body and trace fossil and in northern Uruguay, where it is known as the record and support this claim, we also review the Batovı Member of the Tacuarembo Formation (Perea presence of Thyreophora in South America and dis- et al., 2009). The northern limits of this unit are con- cussthesimilaritiesbetweentheLateJurassicfauna trolled by the Jaguari-Mata Fault Zone. Lithologically, of southern Brazil and Uruguay and other correlated they are composed of fine- to coarse-grained sandstones faunas worldwide distributed. and rare mudstones of fluvial and eolian depositional systems (Lavina et al., 1985; Scherer et al., 2000). Although variable, the Guara Formation has an average Geological and chronostratigraphical setting thickness of 200 m and unconformably overlies the flu- The Parana Basin is a South American intracratonic vial deposits of the Lower Triassic Sanga do Cabral SS, basin (1,700,000 km2) that covers part of southern Brazil, and is in its turn overlain by the eolian deposits of the Argentina, Paraguay, and Uruguay (Milani et al., 2007). Lower Cretaceous Botucatu Formation (Scherer et al., Six supersequences (SS) have been identified within the 2000; Scherer and Lavina 2005). Basin by Milani et al. (2007), from base to top: Rio Ivaı The fluvial facies thin out toward the south and are (Ordovician/Silurian); Parana (Devonian); Gondwana I interdigitated with fine- to medium-grained sandstones (Carboniferous/Early Triassic); Gondwana II (Middle to with large-scale cross-stratification and horizontal lami- Late Triassic); Gondwana III (Late Jurassic/Early Creta- nation, interpreted as eolian dune and sand sheet depos- ceous); and Bauru (Late Cretaceous). Zerfass et al. (2003) its, respectively (Scherer and Lavina, 2005). In the eolian separated the top of the Gondwana I SS strata in a new sand sheet deposits, a vertical transition between wind second-order sequence, the Early Triassic (Scythian) ripples and adhesion strata (crinkled lamination) indi- Sanga do Cabral SS. The Gondwana III SS comprises the cates changes in the substrate wetness. The accumulation Late Jurassic Sequence, which is constituted by the flu- of eolian facies in the Guara Formation was controlled vio–eolian deposits of the Guara Formation, and the by oscillations between arid and semi-arid conditions Early Cretaceous Sequence, comprising both the (Scherer and Lavina, 2005, 2006). Figure 1. Location map of the Guara Formation outcrop belt in the Rio Grande do Sul State, southern Brazil, and the occurrence of anky- losaur tracks (Modified from Scherer and Lavina, 2005). JMFZ: Jaguari–Mata Fault Zone. ICHNOS 3 Until now, the fossil record of the Guara Formation is represented by four letters (RSCT), the first two letters restricted to eolian facies and is composed of theropod, referring to the municipal district (RS, Rosario do Sul) sauropod, and ornithopod footprints,