New Australian sauropods shed light on Cretaceous dinosaur palaeobiogeography
Stephen F. Poropat, Philip D. Mannion, Paul Upchurch, Scott A. Hocknull, Benjamin P. Kear, Martin Kundrát, Travis R. Tischler, Trish Sloan, George H. K. Sinapius, Judy A. Elliott & David A. Elliott
Scientific Reports 6, Article number: 34467 (2016)
Biogeography Palaeontology Phylogenetics Taxonomy
Received: 15 April 2016 Accepted: 13 September 2016 Published online: 20 October 2016
Australian dinosaurs have played a rare but controversial role in the debate surrounding the effect of Gondwanan break-up on Cretaceous dinosaur distribution. Major spatiotemporal gaps in the Gondwanan Cretaceous fossil record, coupled with taxon incompleteness, have hindered research on this effect, especially in Australia. Here we report on two new sauropod specimens from the early Late Cretaceous of Queensland, Australia, that have important implications for Cretaceous dinosaur palaeobiogeography. Savannasaurus elliottorum gen. et sp. nov. comprises one of the most complete Cretaceous sauropod skeletons ever found in Australia, whereas a new specimen of Diamantinasaurus matildae includes the first ever cranial remains of an Australian sauropod. The results of a new phylogenetic analysis, in which both Savannasaurus and Diamantinasaurus are recovered within Titanosauria, were used as the basis for a quantitative palaeobiogeographical analysis of macronarian sauropods. Titanosaurs achieved a worldwide distribution by at least 125 million years ago, suggesting that mid-Cretaceous Australian sauropods represent remnants of clades which were widespread during the Early Cretaceous. These lineages would have entered Australasia via dispersal from South America, presumably across Antarctica. High latitude sauropod dispersal might have been facilitated by Albian–Turonian warming that lifted a palaeoclimatic dispersal barrier between Antarctica and South America.
We would like to thank the staff from the Australian Age of Dinosaurs Natural History Museum, the Queensland Museum, and the University of Queensland, and all of the volunteers, who participated in the “Elliot” and “Wade” digs from 2001–2005, and who prepared all of the specimens. We also thank the Elliott family for reinvigorating the search for dinosaurs in western Queensland, and for allowing excavations to take place on Belmont Station from 2001–2005. We are also grateful to all those who allowed us to study sauropod material in their care. S.F.P., S.A.H. and B.P.K.’s research was funded by an Australian Research Council Linkage Grant (LP100100339). P.D.M.’s research was supported by an Imperial College London Junior Research Fellowship. P.U.’s contribution was facilitated by a Leverhulme Trust Research Grant (RPG-129). M.K. was funded by the Swedish Research Council.
Stephen F. Poropat, Philip D. Mannion & Paul Upchurch
These authors contributed equally to this work.
Department of Earth Sciences, Uppsala University, Uppsala, Sweden
Stephen F. Poropat & Benjamin P. Kear
Australian Age of Dinosaurs Museum of Natural History, The Jump-Up, Winton, Queensland, Australia
Stephen F. Poropat, Travis R. Tischler, Trish Sloan, George H. K. Sinapius, Judy A. Elliott & David A. Elliott
Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
Philip D. Mannion
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom
Geosciences, Queensland Museum, Hendra, Queensland, Australia
Scott A. Hocknull
Museum of Evolution, Uppsala University, Norbyvägen 16, SE-752 36 Uppsala, Sweden
Benjamin P. Kear
Department of Ecology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, SK-84215, Bratislava, Slovak Republic
Center for Interdisciplinary Biosciences, Faculty of Science, University of Pavol Jozef Šafárik, Jesenná 5, SK-04154, Košice, Slovak Republic
S.F.P., P.D.M., P.U., S.A.H. and B.P.K. designed the project. S.A.H., T.S., G.H.K.S., J.A.E. and D.A.E. oversaw the collection, preparation and curation of the fossils. S.F.P., P.D.M. and P.U. described the specimens, and M.K. analysed the endocranial structure of AODF 836. S.F.P., P.D.M. and P.U. scored the specimens for the phylogenetic analysis, and P.D.M. ran the analysis. P.U. ran the quantitative palaeobiogeographic analysis. S.F.P., S.A.H., M.K. and T.R.T. assembled the figures. S.F.P., P.D.M. and P.U. wrote and prepared the Supplementary Information. All authors contributed to the writing of the paper.
The authors declare no competing financial interests.
Correspondence to Stephen F. Poropat.