Cretaceous Research 32 (2011) 236e243 Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes A new pterodactyloid pterosaur from the Santana Formation (Cretaceous) of Brazil David M. Martill School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth PO1 3QL, United Kingdom article info abstract Article history: A partial skull comprising fused maxilla/premaxilla and palate of a ctenochasmatoid pterosaur from the Received 13 July 2009 Santana Formation of the Araripe Basin in NE Brazil is named as the new genus and species Unwindia Accepted in revised form 1 December 2010 trigonus gen. et sp. nov. on account of its long slender rostrum, isodonty with raised dental alveoli and Available online 14 December 2010 dentition of seven tooth pairs restricted to the portion of the rostrum anterior to the nasoantorbital fenestra. Unwindia is assigned to the Ctenochasmatoidea, and is probably basal within the clade. Keywords: Ó 2010 Elsevier Ltd. All rights reserved. Pterosauria Ctenochasmatoidea Unwindia trigonus gen. et sp. nov. Santana Formation Brazil Early Cretaceous 1. Introduction world, surpassing the Jurassic Solnhofen Limestone (Wellnhofer, 1970, 1975) and approaching the diversity of the combined Yixian Pterosaur remains are both abundant and diverse in the Santana and Jiufotang formations of the Chinese Jehol Group (Lü et al., Formation fossil Lagerstätte of Brazil with some 12 nominal genera 2006a). A new partial pterosaur skull described here indicates the (Anhanguera, Araripedactylus, Araripesaurus, Brasileodactylus, Colo- presence of a new genus and species of ctenochasmatoid pterosaur borhynchus, Cearadactylus, Criorhynchus, Pricesaurus, Santana- in the Santana Formation assemblage, a group that were wide- dactylus, Tapejara, Thalassodromeus, Tupuxuara) and an undescribed spread in the Early Cretaceous of South America. edentulous form similar perhaps to Chaoyangopterus. The genera encompass more than 20 species (Price, 1971; Wellnhofer, 1985, 1987, 1991; Buisonjé de, 1980; Leonardi and Borgomanero, 1985; 2. The new specimen Wellnhofer and Kellner, 1991; Dalla Vecchia, 1993; Kellner and Tomida, 2000; Fastnacht, 2001; Unwin, 2002; Veldmeijer, 2002, The new specimen was obtained from a fossil digger in the small 2003, 2006; Martill and Naish, 2006) although some are of town of Santana do Cariri, southern Ceará, in north east Brazil. This dubious validity (e.g. Araripedactylus dehmi Wellnhofer, 1977; Ara- region is palaeontologically rich and a thriving commercial trade in ripesaurus castilhoi' Price, 1971; Brasileodactylus araripensis Kellner, fossils has developed, especially within the confines of what is now 1984; Pricesaurus megalodon Martins-Neto,1986). Nevertheless, the the Araripe Geopark World Heritage Site (Martill and Heads, 2007). assemblage is diverse and includes Tapejaridae, Thalassodromidae, Although not obtained from in situ, there is little reason to doubt Ornithocheiridae and Ctenochasmatidae (Table 1). The Santana that the specimen comes from the Santana do Cariri region, and Formation pterosaurs occur either as partly crushed, but frequently from the Romualdo Member of the Santana Formation, which articulated specimens in late diagenetic concretions, and as yields abundantly fossiliferous concretions of comparable lithology uncrushed, 3-D specimens, sometimes with soft tissues preserved (Martill, 1993; Fara et al., 2005). in eodiagenetic carbonate concretions (Martill, 1988, 1997; Martill The specimen, housed in the collection of the Museum für and Unwin, 1990). This abundance and diversity make the San- Naturkunde, Karlsruhe, Germany, SMNK PAL 6597 comprises tana Formation one of the richest sources of pterosaur fossils in the a fused left and right premaxilla and maxilla in a carbonate concretion that has been split to reveal the right side of the rostrum (Fig. 1). The counterpart to the concretion is missing. Some bone compacta has fallen away from the specimen revealing an internal Abbreviations: NHMU, Natural History Museum, London, UK; CAMS, Sedgwick mould of crystalline calcite. Four teeth are present in the anterior Museum, Cambridge, UK; SMNK, Staatliches Museum für Naturkunde, Karlsruhe, Germany; YORM, Yorkshire Museum, York, UK. jaws of the right side (Fig. 1b) and mechanical preparation has been E-mail address: [email protected]. employed to reveal the anterior border of the nasoantorbital 0195-6671/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2010.12.008 D.M. Martill / Cretaceous Research 32 (2011) 236e243 237 Table 1 three-dimensionality of the right side and palatal surface has Names applied to Santana Formation pterosaurs. survived. Anhanguera santanae (Wellnhofer, 1985) Anhanguera blittersdorffi (Campos and Kellner, 1985) Araripesaurus castilhoi (Price, 1971) 2.1. Systematic palaeontology Araripedactylus dehmi (Wellnhofer, 1977) nomen dubium Brasileodactylus araripensis (Kellner, 1984) PTEROSAURIA (Kaup, 1834) Cearadactylus atrox (Leonardi and Borgomanero, 1985) PTERODACTYLOIDEA (Plieninger, 1901) Cearadactylus? ligabuei (Dalla Vecchia, 1993) LOPHOCRATIA (Unwin, 2003) CTENOCHASMATOIDEA (Unwin, 1995) Coloborhynchus robustus (Fastnach, 2001) Coloborhynchus speilbergei (Veldmeijer, 2003) UNWINDIA gen. nov. Coloborhynchus piscator (Kellner and Tomida, 2000) Pricesaurus megalodon (Martins-Neto, 1986) Diagnosis and etymology: see for type and only species below. Santanadactylus pricei (Wellnhofer, 1985) Unwindia trigonus gen. et sp. nov. Santanadactylus araripensis (Wellnhofer, 1985) Santanadactylus brasiliensis (Buisonjé de, 1980) Santanadactylus spixi (Wellnhofer, 1985) Derivation of name: Unwindia, after Dr David Unwin; trigonus, referring to the triangular cross-section of the rostrum. Tropeognathus mesembrinus (Wellnhofer, 1987) Tropeognathus robustus (Wellnhofer, 1987) Tapejara wellnhoferi (Kellner, 1989) Holotype: partial rostrum with teeth, SMNK PAL 6597 Tupuxuara longicristatus (Kellner and Campos, 1988) (Fig. 1aec). Tupuxuara leonardi (Kellner and Campos, 1994) Tupuxuara deliridamus (Witton, 2009) Thalassodromeus sethi (Kellner and Campos, 2002) Type locality: Santana do Cariri region, southern Ceará, NE Brazil. Type horizon and age: Romualdo Member of the Santana fenestra of the left side (Fig. 1c) and parts of the palate. The region Formation, Araripe Group. Late Early Cretaceous, probably latest of the nasoantorbital fenestra of the right side has suffered from Albian (see Martill, 2007). fracturing and is not clearly discernible (Fig. 1a). Complete prepa- ration of the specimen has not occurred due to the very fragile Diagnosis: U. trigonus can be distinguished from other ptero- nature of the thin bone compacta. The matrix of the concretion is an saurs by the reduced dentition of the maxilla/premaxilla of only 7 ostracod limestone of light buff shade, one of several typical tooth pairs all of which lie anterior to the nasoantorbital fenestra: lithologies of Santana Formation concretions (Martill, 1997). this is apomorphic for the species. The teeth are of similar size, Crushing of the anterior premaxilla on the left side indicates that distinguishing them from the marked heterodonty of other Santana the concretion is not of the earliest diagenetic variety, but some formation tooth-bearing pterosaurs. Fig. 1. New ctenochamatoid pterosaur Unwindia trigonus (SMNK PAL 6597) from the Romualdo Member of the Santana Formation, NE Brazil. (a) Rostrum within concretion seen in right lateral view. The line diagram above highlights the bones and teeth; (b) detail of the dentition and anterior alveoli; (c) anterior margin of the nasoantorbital fenestra (nasoantorbital fenestra) of the left side with the premaxilla/maxilla suture arrowed. Scale bars 10 mm. 238 D.M. Martill / Cretaceous Research 32 (2011) 236e243 Table 2 compaction and it is possible, though unlikely that one more Table of measurements. alveolus could have been accommodated in the jaw tip. Teeth are Length of specimen 221.0 mm present in the posterior most four alveoli of the right side. The teeth Length from anterior border 192.0 mm are simple, slightly laterally compressed cones slightly deflected of Nasoantorbital Fenestra to est. toward the midline of the palate. The largest tooth has a recon- anterior tip of rostrum structed height of 9 mm (Table 2), the smallest, and anterior most Height of rostrum at anterior 36.0 mm border of Nasoantorbital Fenestra tooth is a partially erupted example only 5 mm high. The dental Length of alveolus 1 indet. (3.5 mm) alveoli have a slightly oval outline with the long axis parallel with (number in brackets ¼ distance to next alveolus) the rostral long axis. The anterior two alveoli are slightly more Length of alveolus 2 5.5 mm (4.0 mm) round than those located posteriorly. The alveolar borders are Length of alveolus 3 5.0 mm (3.0 mm) Length of alveolus 4 4.0 mm (4.0 mm) slightly raised. There is a very slight lateral expansion distally of the Length of alveolus 5 5.5 mm (6.5 mm) tooth-bearing part of the rostrum and alveoli 2 and 3 are more Length of alveolus 6 5.5 mm (8.0 mm) laterally located than the posterior alveoli. Length of alveolus 7 5.0 mm The anterior border of the nasoantorbital fenestra is sharply Width of rostrum at 7th alveolus 10.0 mm rounded such that the dorsal and ventral margins must have been nearly parallel along much of its length. Although the suture 2.1.1. Description between the maxilla and premaxilla is distinct, the