Historical Biology An International Journal of Paleobiology ISSN: 0891-2963 (Print) 1029-2381 (Online) Journal homepage: http://www.tandfonline.com/loi/ghbi20 The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil Xin Cheng, Renan A. M. Bantim, Juliana M. Sayão, Alexander W. A. Kellner, Xiaolin Wang & Antônio Á. F. Saraiva To cite this article: Xin Cheng, Renan A. M. Bantim, Juliana M. Sayão, Alexander W. A. Kellner, Xiaolin Wang & Antônio Á. F. Saraiva (2018): The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil, Historical Biology, DOI: 10.1080/08912963.2018.1491567 To link to this article: https://doi.org/10.1080/08912963.2018.1491567 Published online: 04 Jul 2018. Submit your article to this journal View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ghbi20 HISTORICAL BIOLOGY https://doi.org/10.1080/08912963.2018.1491567 ARTICLE The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil Xin Chenga,b, Renan A. M. Bantima, Juliana M. Sayãoc, Alexander W. A. Kellnerd, Xiaolin Wangb,e and Antônio Á. F. Saraivaa aLaboratório de Paleontologia, Universidade Regional do Cariri, Crato, CE, Brazil; bKey Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (CAS), Beijing, China; cLaboratório de Paleobiologia e Microestruturas, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Vitória de Santo Antão, PE, Brazil; dLaboratory of Systematics and Taphonomy of Fossil Vertebrates, Department of Geology and Paleontology,Museu Nacional/UFRJ, Rio de Janeiro, RJ, Brazil; eUniversity of Chinese Academy of Sciences, Beijing, China ABSTRACT ARTICLE HISTORY The Early Cretaceous deposits of the Araripe Basin in northeast Brazil has yielded numerous vertebrate Received 24 April 2018 fossils, in which pterosaurs are the predominant tetrapods. Almost all specimens of this extinct group of Accepted 17 June 2018 fl ying reptiles recovered from this basin come from two stratigraphic units, the Crato and Romualdo KEYWORDS Formations, with the pterosaurs from the former being usually small to middle-sized and large individuals Anhangueridae; Pterosauria; (with a maximized wingspan over 5 m) being only found in the latter. Here we report on a new specimen bone histology; Crato (MPSC R 1221) composed of a partial right wing, which is the largest pterosaur discovered from the Crato Formation; Cretaceous; Formation so far, having an estimated maximized wingspan of 5.5 m. Despite the incompleteness of this Brazil material, MPSC R 1221 can be referred to the Anhangueridae based on the length ratio between the metacarpal IV and the first wing phalanx. According to the osteohistological study and the degree of fusion, MPSC R 1221 represents a sub-adult individual, showing that the animal had not reached the maximum size before its death. The present study shows that large-sized pterosaurs were also present in the Crato Formation and that their rarity might be an artefact of preservation. Introduction 2013), which was recovered from the Romualdo Formation. It Pterosaurs are a group of extinct flying reptiles that became the has a wingspan of about 1.8 times larger than Arthurdactylus first vertebrates to developed powered flight (e.g., Wellnhofer conandoylei (SMNK 1132 PAL) whose wingspan was estimated 1991a; Kellner 2006;Chengetal.2017). The Araripe Basin being about 4.6 m (Frey and Martill 1994).Thelatterwassofarthe shows several important localities that yielded some of the best largest pterosaur from that stratigraphic unit. pterosaur material known worldwide (e.g., Wellnhofer 1985, Here we report on a partial right wing (MPSC R 1221) of the 1991b; Kellner and Tomida 2000). Several other fossils have largest pterosaur recovered from the Crato Formation so far, with been recorded in this region along the years (e.g., Kellner 1987; anestimatedwingspanexceeding5m.Wehavealsoperformed Maisey 1991), but flying reptiles predominate among tetrapods osteohistological sections to further assign the bone maturity of (e.g., Maisey 1991; Saraiva et al. 2014). Since the first specimen this new specimen. reported by Price (1971), over twenty-seven pterosaur species have been described up to now (e.g., Wellnhofer 1987;Freyand Institutional Abbreviations Martill 1994; Kellner and Campos 2002, 2007;Freyetal.2003a, AMNH-American Museum of Natural History, New York, USA. 2003b;Witton2009; Kellner 2013;Bantimetal.2014; Pêgas et al. 2016) some having exceptionally well preserved soft tissue (e.g., MN-Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Kellner 1996). Despite the controversy of taxonomic assignment of some taxa (e.g., Fastnacht 2001; Veldmeijer 2003;Rodrigues MPSC-Museu de Paleontologia Plácido Cidade Nuvens, and Kellner 2008; Martill and Unwin 2012; Pinheiro and Universidade Regional do Cariri, Santana do Cariri, Ceará, Brazil. Rodrigues 2017), two pterosaur groups, the toothed anhanguerids SMNK-Staatliches Museum für Naturkunde, Karlsruhe, and the toothless tapejarids, predominate (e.g., Campos and Germany. Kellner 1985; Kellner 1989;VilaNovaandSayão2012). Almost all these materials were discovered from two distinct UP-University of Portsmouth School of Earth and Environmental Sciences, UK. stratigraphic units: the Crato (Aptian) and the Romualdo (Aptian/ Albian) Formations (Pons et al. 1990; Kellner and Campos 1999; Neumann and Cabrera 1999; Valença et al. 2003; Kellner et al. Material and methods 2013), with only one exception (Martill 2008)whoseprovenance needstobeconfirmed. Among the most interesting findsisthe The specimen (MPSC R 1221) is composed of an incomplete right largest pterosaur species of Gondwanan deposit (Kellner et al. wing with the first wing phalanx exposed in ventral view. It was CONTACT Xin Cheng [email protected] © 2018 Informa UK Limited, trading as Taylor & Francis Group Published online 04 Jul 2018 2 X. CHENG ET AL. discovered by Plácido Cidade Nuvens, former director of the local Specimen paleontological museum at a quarry situated close to the town MPSC R 1221, partial front limb housed in the Santana do Cariri (Ceará State). The specimen arrived at the Palaeontology Museum Plácido Cidade Nuvens, Santana do museum having several parts put together by a plastic acrylic Cariri, CE, Brazil. resin, with a small misplacement at the manual digits area. At Locality and horizon the museum, the specimen was prepared mechanically by steel Crato Formation, Early Cretaceous (Aptian), Araripe needle and pneumatic micro tools under a microscope (PDV Basin, Santana do Cariri, Crato, Northeastern Brazil. TS-30Y). Comments MPSC R 1221 was measured, photographed and described The specimen is not complete enough to allow a classifica- for bone microstructure investigation before sectioned, tion at the generic or specific level. Wing element ratios are according to the methodology proposed by Lamm (2013). generally used in the classification of incomplete pterosaur Traditionally, osteohistological studies use the area of the materials (e.g., Vila Nova and Sayão 2012). Based on the bone diaphysis since this region preserves a comparatively comparison of the proportion between the first wing phalanx larger amount of cortical tissue and growth markers (e.g., and the wing metacarpal among several clades (Table 1), the Francillon-Vieillot et al. 1990; Andrade and Sayão 2014). ratio of MPSC R 1221 is consistent with the Anhangueridae, However, some samples were sectioned in the portion of the to which this specimen is referred. Although not exclusive of metaphysis (second wing phalanx) following original the Araripe deposits (e.g., Rodrigues and Kellner 2013), this breakages of the limestone plates. A sample (approximately clade is well represented in the Romualdo Formation (e.g., 1cm of thickness) from the first and second wing digits was Kellner and Tomida 2000). obtained for osteohistological sections. The sectioned samples were immersed in clear epoxy resin Resapol T-208 catalyzed Description and comparison with Butanox M50. They were cut with the aid of a micro rectify (Dremel 4000 with extender cable 225) coupled to a MPSC R 1221 was preserved in a pale-yellow limestone diamond disk and left to dry. The section was ground and slab and the bones were flattened, a typical feature of the polished in a metal polishing machine (AROPOL-E, fossils recovered from the Crato Formation (Figure 1). AROTEC LTDA) using AROTEC abrasive grit (grit size 60/ The specimen is composed of an incomplete right wing, P60, 120/P120, 320/P400, 1200/P2500) to remove scratches including proximal and distal carpals, wing metacarpal, from the block. After the blocks were polished, they were another metacarpal (probably metacarpal I), manual glued on glass slides and thinned again, in order to make the digits, and first and second wing phalanges. The metacar- blocks translucent enough to enable the observation of osteo- pals and wing phalanges are still articulated while the histological structures under a biological microscope (Zeiss carpals and manual digits are displaced not far from Axio Imager 2). As usually used for paleobiological interpre- their original anatomical position. tations, all slabs were oriented exclusively in transversal view The carpal region is exposed in dorsal view, with all elements (see Lamm 2013 for a review). of the proximal and distal carpal series