Alcheringa For Peer Review Only Reappraisal of Austro saurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur Journal: Alcheringa Manuscript ID TALC-2017-0017.R1 Manuscript Type: Standard Research Article Date Submitted by the Author: n/a Complete List of Authors: Poropat, Stephen; Swinburne University of Technology, Department of Chemistry and Biotechnology; Australian Age of Dinosaurs Natural History Museum Nair, Jay; University of Queensland, Biological Sciences Syme, Caitlin; University of Queensland, Biological Sciences Mannion, Philip D.; Imperial College London, Earth Science and Engineering Upchurch, Paul; University College London, Earth Sciences, Hocknull, Scott; Queensland Museum, Geosciences Cook, Alex; Queensland Museum, Palaeontology & Geology Tischler, Travis; Australian Age of Dinosaurs Natural History Museum Holland, Timothy; Kronosaurus Korner <i>Austrosaurus</i>, Dinosauria, Sauropoda, Titanosauriformes, Keywords: Australia, Cretaceous, Gondwana URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Page 1 of 126 Alcheringa 1 2 3 4 5 6 7 1 8 9 1 Reappraisal of Austrosaurus mckillopi Longman, 1933 from the 10 11 12 2 Allaru Mudstone of Queensland, Australia’s first named 13 14 For Peer Review Only 15 3 Cretaceous sauropod dinosaur 16 17 18 4 19 20 5 STEPHEN F. POROPAT, JAY P. NAIR, CAITLIN E. SYME, PHILIP D. MANNION, 21 22 6 PAUL UPCHURCH, SCOTT A. HOCKNULL, ALEX G. COOK, TRAVIS R. TISCHLER 23 24 7 and TIMOTHY HOLLAND 25 26 27 8 28 29 9 POROPAT , S. F., NAIR , J. P., SYME , C. E., MANNION , P. D., UPCHURCH , P., HOCKNULL , S. A., 30 31 10 COOK , A. G., TISCHLER , T.R. & HOLLAND , T. 201#. Reappraisal of Austrosaurus mckillopi 32 33 11 Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous 34 35 12 sauropod dinosaur. Alcheringa XX, XX–XX. ISSN ###. 36 37 38 13 39 40 14 Austrosaurus mckillopi Longman, 1933 was the first Cretaceous sauropod reported from 41 42 15 Australia, and the first Cretaceous dinosaur reported from Queensland (northeast Australia). 43 44 16 This sauropod taxon was established on the basis of several fragmentary presacral vertebrae 45 46 17 (QM F2316) derived from the uppermost Lower Cretaceous (upper Albian) Allaru Mudstone, 47 48 18 at a locality situated 77 km west-northwest of Richmond, Queensland. Prior to its rediscovery 49 50 19 in 2014, the type site was considered lost after failed attempts to relocate it in the 1970s. 51 52 20 Excavations at the site in 2014 and 2015 led to the recovery of several partial dorsal ribs and 53 54 21 fragments of presacral vertebrae, all of which clearly pertainpertained to a single sauropod 55 56 57 58 59 60 URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Alcheringa Page 2 of 126 1 2 3 4 5 6 7 2 8 9 22 dinosaur. The discovery of new material belonging toof the type individual of Austrosaurus 10 11 23 mckillopi , in tandem with a reassessment of the type seriesmaterial collected in the 1930s , has 12 13 24 facilitated the rearticulation of the specimen. The resultant vertebral series comprises six 14 For Peer Review Only 15 25 presacral vertebrae—the posteriormost cervical and five anteriormost dorsals—in association 16 17 26 with five left dorsal ribs and one right one. The fragmentary nature of the type specimen has 18 19 27 historically hindered assessments of the phylogenetic affinities of Austrosaurus , as has the 20 21 28 fact that these evaluations were often based on a subset of the type material. The reappraisal 22 23 29 of the type series of Austrosaurus presented herein, on the basis of both external morphology 24 25 30 and internal morphology visualised through CT data, validates it as a diagnostic 26 31 titanosauriform taxon (, tentatively placed in Somphospondyli ),, and characterised by the 27 28 32 possession of an accessory lateral pneumatic foramen on dorsal vertebra I (a feature which 29 30 33 appears to be autapomorphic) and by the presence of a robust ventral midline ridge on the 31 32 34 centra of dorsal vertebrae I and II. The interpretation of the anteriormost preserved vertebra 33 34 35 in Austrosaurus as a posterior cervical has also prompted the re-evaluation of an isolated, 35 36 36 partial, posterior cervical vertebra (QM F6142, the “Hughenden sauropod”) derived from the 37 38 37 upper Albian Toolebuc Formation (which underlies the Allaru Mudstone). Although this 39 40 38 vertebra preserves an apparent unique character of its own (a spinopostzygapophyseal lamina 41 42 39 fossa), it is not able to be referred unequivocally to Austrosaurus and is retained as 43 44 40 Titanosauriformes indet. Austrosaurus mckillopi is one of the oldest known sauropods from 45 46 41 the Australian Cretaceous based on skeletal remains, and potentially provides phylogenetic 47 48 42 and/or palaeobiogeographic context for later taxa such as Wintonotitan wattsi , 49 50 43 Diamantinasaurus matildae and Savannasaurus elliottorum . 51 52 44 53 54 55 56 57 58 59 60 URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Page 3 of 126 Alcheringa 1 2 3 4 5 6 7 3 8 9 45 Stephen F. Poropat [[email protected]; [email protected]] (corresponding 10 11 46 author), Department of Chemistry and Biotechnology, Swinburne University of Technology, 12 13 47 John St, Hawthorn, Victoria 3122, Australia and Australian Age of Dinosaurs Museum of 14 For Peer Review Only 15 48 Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia; 16 17 49 Jay P. Nair [[email protected]; [email protected]] School of Biological Sciences, The 18 19 50 University of Queensland, St Lucia, Queensland 4072, Australia; Caitlin E. Syme 20 21 51 [[email protected]] School of Biological Sciences, The University of 22 23 52 Queensland, St Lucia, Queensland 4072, Australia; Philip D. Mannion 24 25 53 [[email protected]] Department of Earth Science and Engineering, Imperial 26 54 College London, South Kensington Campus, London SW7 2AZ, United Kingdom; Paul 27 28 55 Upchurch [[email protected]] Department of Earth Sciences, University College 29 30 56 London, Gower Street, London WC1E 6BT, United Kingdom; Scott A. Hocknull 31 32 57 [[email protected]] Geosciences, Queensland Museum, 122 Gerler Rd, Hendra, 33 34 58 Queensland 4011, Australia; Alex G. Cook [[email protected]] School of Earth 35 36 59 Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Travis R. 37 38 60 Tischler [[email protected]] Australian Age of Dinosaurs Museum of Natural 39 40 61 History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia; Timothy 41 42 62 Holland [[email protected]] Kronosaurus Korner, 91 Goldring St, Richmond, 43 44 63 Queensland 4822, Australia. Received XX.X.201X; revised XX.X.201X; accepted XX.X.201X. 45 46 64 47 48 49 65 Key words: Austrosaurus ; Dinosauria; Sauropoda; Titanosauriformes; Australia; Cretaceous; 50 51 66 Gondwana. 52 53 54 67 55 56 57 58 59 60 URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Alcheringa Page 4 of 126 1 2 3 4 5 6 7 4 8 9 68 SAUROPOD dinosaur fossils were not reported from Australia until 1926, despite the 10 11 69 fact that the first discovery of an Australian sauropod specimen was made in 1913. This 12 13 70 incomplete humerus (QM F311)—found in Cretaceous strata near the town of Blackall in 14 For Peer Review Only 15 71 Queensland—was not determined to pertain to a dinosaur, let alone a sauropod, until 1980 16 17 72 (Molnar 2001b). The first Australian sauropod specimen that was recognised as such was 18 19 73 discovered in 1924 near the town of Roma, Queensland. This partial skeleton (QM F1659) 20 21 74 was designated the type of Rhoetosaurus brownei and remains one of only two Jurassic 22 23 75 sauropod specimens known from Australia (Longman 1926, 1927a, b, 1929, Thulborn 1985, 24 25 76 Vickers-Rich & Rich 1993, Rich & Vickers-Rich 2003, Nair & Salisbury 2012). The other, a 26 77 distal caudal vertebra (UWA 82468), was found in the mid-1970s in Middle Jurassic rocks 27 28 78 near Geraldton, Western Australia (Long 1992). 29 30 31 79 Cretaceous sauropod remains are only known from three Australian states. Footprints 32 33 80 found in the Broome Sandstone (Valanginian–Barremian) of the Dampier Peninsula 34 35 81 constitute the only evidence of Cretaceous sauropods in Western Australia (Thulborn et al. 36 37 82 1994, Thulborn 2012, Salisbury et al. in press2017 ), whereas opalised sauropod teeth (AM 38 39 83 F66769, AM F66770) from the Griman Creek Formation (middle Albian) of Lightning Ridge 40 41 84 are all that has been reported from New South Wales (Smith & Smith 1999, Molnar & 42 43 85 Salisbury 2005, Molnar 2011b). In Queensland, the Griman Creek Formation has yielded two 44 86 possible sauropod elements: a fragmentary right ischium (QM F54817) and a possible 45 46 87 vertebral fragment (QM F11043; Molnar 2011b). 47 48 49 88 The Eromanga Basin in Queensland has produced the overwhelming majority of 50 51 89 Australia’s sauropod skeletal remains. Rare specimens have been described from the 52 53 90 Toolebuc Formation and the Allaru Mudstone, both of which constitute upper Albian marine 54 55 56 57 58 59 60 URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Page 5 of 126 Alcheringa 1 2 3 4 5 6 7 5 8 9 91 deposits (Molnar & Salisbury 2005). However, the bulk of the known sauropod remains from 10 11 92 the Eromanga Basin derive from the youngest Cretaceous unit preserved therein, the 12 13 93 uppermost Albian–lower Turonian Winton Formation (Coombs & Molnar 1981, Molnar & 14 For Peer Review Only 15 94 Salisbury 2005, Greentree 2011, Bryan et al.