Cretaceous Research 34 (2012) 1e9 Contents lists available at SciVerse ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes The world’s largest toothed pterosaur, NHMUK R481, an incomplete rostrum of Coloborhynchus capito (Seeley, 1870) from the Cambridge Greensand of England David M. Martill a,*, David M. Unwin b a Palaeobiology Research Group, School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth PO1 3QL, UK b School of Museum Studies, University of Leicester, 19 University Road, Leicester LE1 7RF, UK article info abstract Article history: The assignment of a fragment of the anterior tip of a pterosaur rostrum from the Cenomanian Cambridge Received 1 June 2011 Greensand of eastern England to the ornithocheirid Coloborhynchus capito (Seeley, 1870) is confirmed. Accepted in revised form 6 September 2011 The fragment represents partial left and right fused premaxillae and retains broken teeth within alveoli. Available online 29 September 2011 A width across the palate of 57.4 mm, a height at the anterior rostrum in excess of 95 mm and a tooth with a diameter of 13 mm at the base of the crown indicates a remarkably large individual, tentatively Keywords: estimated to have had a skull length in excess of 0.75 m and a wing span of up to 7 m. This fragment Pterosauria represents the largest toothed pterosaur yet reported. This find, and several other large postcranial Coloborhynchus Cretaceous fragments from the Cambridge Greensand, suggest that ornithocheirids, toothed ornithocheiroids known e England from the earliest Early to early Late Cretaceous (Valanginian Cenomanian) achieved very large, but not Evolution giant size. Pteranodontids, edentulous ornithocheiroids currently known only from the mid Upper Gigantism Cretaceous (Coniacianeearly Campanian), reached similar dimensions, up to 7.25 m in wing span. Contrary to popular myth, however, ornithocheiroids did not attain the giant sizes (wing spans of 10 m or more) achieved by azhdarchids in the late Late Cretaceous (CampanianeMaastrichtian). Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction undertaken by Hooley (1914) and, more recently, the entire pterosaur assemblage was revised by Unwin (1991, 2001) who The Cretaceous Cambridge Greensand of eastern England was confirmed the presence of the ornithocheirids Anhanguera, excavated from the mid to late 19th century as a source of phos- Coloborhynchus and Ornithocheirus, as well as the lonchodectid phate for agricultural fertiliser (Grove, 1976), during which period Lonchodectes and the indeterminate edentulous pterosaur it yielded many fossils including vertebrates (Seeley, 1969). These Ornithostoma. almost exclusively fragmentary remains were derived from Despite the fragmentary nature of the Cambridge Greensand underlying Albian strata based on the associated derived pterosaur fossils, Owen recognised that some fragments repre- (reworked) invertebrate assemblage (Unwin, 2001). Among the sented individuals of considerable size and, for one taxon, “Pter- various fossils collected, which represent fish, ichthyosaurs, odactylus” [¼Coloborhynchus] sedgwickii, he estimated a wing span plesiosaurs, crocodiles, turtles and dinosaurs (including birds), of 22 ft (w6.55 m) (Owen, 1859a). Here we describe NHMUK R481, were many hundreds of bone fragments of pterosaurs. These a fragmentary pterosaur rostrum with teeth from the Cambridge pterosaur remains were first described by Owen (1859a, b, 1860, Greensand in the collections of the Natural History Museum, 1861) and later by Seeley in more than 20 publications spanning London. The specimen, which was first mentioned, but not figured the interval 1864 to 1901 (listed in Unwin, 2001). The most or described, by Unwin (2001), is incomplete and highly damaged: important among these were the “Index” published in 1869 and a combination of ancient reworking and recent phosphate digging. “The Ornithosauria”, which appeared in 1870. Owen erected four None the less it is noteworthy because it represents the largest new species and Seeley added many more, most of which have ornithocheirid found to date and indicates a possible upper limit to proved invalid for various reasons (see Unwin, 2001; Table 1). A the size achieved by toothed pterosaurs, thereby adding to our detailed review of the Cambridge Greensand pterosaurs was understanding of pterosaur evolution in the Cretaceous. The following collection abbreviations are used: CAMSM, Sedgwick * Corresponding author. Museum of Earth Sciences, Cambridge, UK; CSRLV, Centro Studi e E-mail address: [email protected] (D.M. Martill). Ricerche Ligabue, Venice, Italy; IMCF, Iwaki Museum of Coal and 0195-6671/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2011.09.003 2 D.M. Martill, D.M. Unwin / Cretaceous Research 34 (2012) 1e9 Table 1 3. Systematic palaeontology Metric data (in millimetres) for Coloborhynchus robustus (NSM-PV 19892, RGM 401 880) and Coloborhynchus capito (NHMUK R481, CAMSM B 54625). Abbreviations: HL, Pterosauria Kaup, 1834 humerus length; RD, depth of anterior rostral facia; RW, width of anterior rostral facia; SL, skull length; TD, maximum diameter of tooth in dental alveolus # 2; WS, Pterodactyloidea Plieninger, 1901 wing span. Data from Unwin (1991), Kellner and Tomida (2000) and Veldmeijer Ornithocheiroidea Seeley, 1891 (2003). Estimate based on restoration in Fig. 4 shown in parentheses. Ornithocheiridae Seeley, 1870 RW RD TD SL HL WS Genus Coloborhynchus Owen, 1874 NHMUK R481 57.4 (60) 56 13.6 eee CAMSM B 54625 48 44 13.0 eee Junior synonyms. Amblydectes Hooley, 1914; Siroccopteryx Mader NSM-PV 19892 25 21 8.5 616 257 4700 and Kellner, 1999; Tropeognathus (partim) Wellnhofer, 1987; a RGM 401 880 36 35 9.6 712 290 5300e5800 Uktenadactylus Rodrigues and Kellner, 2008. a Estimate based on comparison with NSM-PV 19892 (Kellner and Tomida, 2000) and SMNK 1132PAL (Frey and Martill, 1994). Type species. Coloborhynchus clavirostris Owen, 1874. Fossils, Iwaki, Japan; NHMUK, Natural History Museum, Temporal range. Valanginian to Late Albian (Fastnacht, 2001). London, UK; NSM, National Science Museum, Tokyo, Japan; RGM, National Natuurhistorisch Museum, Leiden, Netherlands; SMNK, Staatliches Museum für Naturkunde, Karlsruhe, Germany; YORM, Yorkshire Museum, York, UK. 2. Locality and stratigraphy The Cambridge Greensand is a thin (w0.6 m) remané deposit occurring at the base of the Chalk Formation in eastern England around the City of Cambridge (Fig. 1). It was extensively excavated between Barrington and Horningsea, Cambridgeshire in the 19th century (Grove,1976) but, with the exception of Barrington Chalk Pit (Mortimore et al., 2001), there are few exposures of this horizon available today. Although the deposit itself is generally considered to be of late Cretaceous, Cenomanian age, its macrofossil assemblage is thought to be derived largely from the underlying early Cretaceous, Albian, Gault Formation, on the basis of derived ammonites asso- ciated with the vertebrate fossils (e.g. Spath, 1923e1943; Owen, 1979; Morter and Wood, 1983). An early Cenomanian age for deposition of the Cambridge Greensand is based on an apparently autochthonous foraminiferan assemblage (Hart, 1973), but Morter and Wood (1983) could not rule out the possibility of a very late Albian age due to the presence of the bivalve Aucinella. The age of the derived vertebrates is now considered to be no older than the Cal- lihoplites auritus ammonite subzone and most likely no younger than upper Stoliczkaia dispar Zone (Cooper and Kennedy, 1977), and they are thus of late Albian age (Unwin, 2001; Fig. 2). Fig. 2. Stratigraphic column for the AlbianeCenomanian (Early/Late Cretaceous) of Fig. 1. Outcrop map of the Gault Clay and Upper Greensand in Eastern England. The Eastern England (modified from Unwin, 2001). Cambridge Greensand Member fossils vertebrate-bearing Cambridge Greensand occurs only in the narrow region between come from hiatus phosphate horizons (indicated by pebble stipple) within the Cen- the arrows. CGS, Cambridge Greensand Member. Based on Mortimore et al. (2001). omanian, but are of Albian age. ?, uncertainty of zonal boundary. D.M. Martill, D.M. Unwin / Cretaceous Research 34 (2012) 1e9 3 Geographic range. England, Texas, Brazil, North Africa, and perhaps As preserved NHMUK R481 is 95 mm high, and 38 mm long Mongolia (Owen, 1874; Lee, 1994; Mader and Kellner, 1999; Unwin with a width of 57.4 mm (Fig. 3AeG). The restored width across the and Bakhurina, 2000; Fastnacht, 2001; Veldmeijer, 2003; Rodrigues anterior palate is approximately 60 mm (Fig. 4). In anterior aspect and Kellner, 2008). the specimen comprises a pair of fused premaxillae with a rounded triangular, boss-like termination within which are located alveoli Coloborhynchus capito Seeley, 1870. for the first pair of teeth. The rostral boss is composed of the dorsally reflected palate (“anterior rostral facies” of Fastnacht, Synonym. Coloborhynchus sp. indet. Martill, 2010, p. 307, fig. 14. 2001) and is approximately 56 mm high with an estimated width of 60 mm at its base. The right alveolus of the first tooth pair Description. The specimen described here is a highly worn fragment of contains a broken tooth with a circular cross-section and a diam- anterior rostrum with broken teeth and is deposited in the collection eter at the crown root junction of w8 mm. The left alveolus is of the Natural History Museum, London, specimen number NHMUK empty with highly abraded margins, but appears to have