This article was downloaded by: [University College London] On: 05 May 2015, At: 06:13 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Historical Biology: An International Journal of Paleobiology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ghbi20 An analysis of pterosaurian biogeography: implications for the evolutionary history and fossil record quality of the first flying vertebrates Paul Upchurcha, Brian Andresb, Richard J. Butlerc & Paul M. Barrettd a Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK b Department of Geology, University of South Florida, 4202 East Fowler Avenue, SCA528, Tampa, FL 33630, USA c Click for updates School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK d Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK Published online: 28 Jul 2014. To cite this article: Paul Upchurch, Brian Andres, Richard J. Butler & Paul M. Barrett (2014): An analysis of pterosaurian biogeography: implications for the evolutionary history and fossil record quality of the first flying vertebrates, Historical Biology: An International Journal of Paleobiology, DOI: 10.1080/08912963.2014.939077 To link to this article: http://dx.doi.org/10.1080/08912963.2014.939077 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. 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This article may be used for research, teaching, and private study purposes. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions It is essential that you check the license status of any given Open and Open Select article to confirm conditions of access and use. Historical Biology, 2014 http://dx.doi.org/10.1080/08912963.2014.939077 An analysis of pterosaurian biogeography: implications for the evolutionary history and fossil record quality of the first flying vertebrates Paul Upchurcha*, Brian Andresb, Richard J. Butlerc and Paul M. Barrettd aDepartment of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK; bDepartment of Geology, University of South Florida, 4202 East Fowler Avenue, SCA528, Tampa, FL 33630, USA; cSchool of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; dDepartment of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK (Received 24 April 2014; accepted 24 June 2014) The biogeographical history of pterosaurs has received very little treatment. Here, we present the first quantitative analysis of pterosaurian biogeography based on an event-based parsimony method (Treefitter). This approach was applied to a phylogenetic tree comprising the relationships of 108 in-group pterosaurian taxa, spanning the full range of this clade’s stratigraphical and geographical extent. The results indicate that there is no support for the impact of vicariance or coherent dispersal on pterosaurian distributions. However, this group does display greatly elevated levels of sympatry. Although sampling biases and taxonomic problems might have artificially elevated the occurrence of sympatry, we argue that our results probably reflect a genuine biogeographical signal. We propose a novel model to explain pterosaurian distributions: pterosaurs underwent a series of ‘sweep-stakes’ dispersal events (across oceanic barriers in most cases), resulting in the founding of sympatric clusters of taxa. Examination of the spatiotemporal distributions of pterosaurian occurrences indicates that their fossil record is extremely patchy. Thus, while there is likely to be genuine information on pterosaurian diversity and biogeographical patterns in the current data-set, caution is required in its interpretation. Keywords: dispersal; diversity; pterosaur; sympatry; Treefitter; vicariance 1. Introduction these and other hypotheses by applying a cladistic After their origin in the Middle or Late Triassic, pterosaurs biogeographical analysis using Treefitter 1.2b (Ronquist acquired a virtually global distribution and their remains 1998; Sanmartin and Ronquist 2004), to a recent are now known from every continent, including Antarctica phylogeny for pterosaurs (Andres et al. 2014) termed (Barrett et al. 2008; see Fossilworks and The Paleobiology here the ‘reference phylogeny’ (Figures 1 and 2), in order Database). As with dinosaurs and many other clades, to determine whether there is any statistical support for pterosaurian evolution took place against a backdrop of particular distribution patterns. Such analyses also enable profound changes in palaeogeography driven by the an assessment of the relative importance of processes such fragmentation of Pangaea, major fluctuations in sea level as vicariance, dispersal, extinction and sympatric specia- and shifts in climatic zones. It is therefore surprising that tion in pterosaurian evolution. Finally, we end with a brief there has been very little detailed study of pterosaurian discussion of the quality of the pterosaurian fossil record biogeographical history (though see Unwin 1996; Wang and future requirements and prospects for further work on et al. 2005, 2007, 2012). This neglect may reflect the the biogeographical history of this clade. Downloaded by [University College London] at 06:13 05 May 2015 intense focus on the flight mechanics of these organisms, and/or the implicit assumption that the geographical distributions of flying organisms are affected more by 2. Pterosaurian distributions through space and time specific ecological requirements rather than large-scale Below, we use the atlas of pterosaurian distributions by vicariance and coherent dispersal patterns. In this paper, Barrett et al. (2008) (with revisions based on The we present the first detailed analytical study of Paleobiology Database (http://paleobiodb.org/#/), Fossil- pterosaurian biogeographical history. First, we provide works (http://fossilworks.org/) and Brian Andres, pers. an overview of the pterosaurian fossil record, summarising obs.) to generate an overview of this group’s spatiotem- where and when particular clades are represented and poral distribution (Figures 3–7, Table 1). This review adding further information based on ghost ranges. Second, provides a framework for the analyses that follow and also we briefly review the small number of previous studies that raises several issues that we believe should be addressed have proposed hypotheses to account for aspects of the by future studies. The reader should note that there are spatiotemporal distributions of pterosaurs. Third, we test some inconsistencies between the various classifications of *Corresponding author. Email: [email protected] q 2014 The Author(s). Published by Taylor & Francis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted. 2 P. Upchurch et al. Figure 1. The pterosaur relationships and stratigraphical/geographical ranges used in the ‘all taxa’ Treefitter data-set. This tree is based on the cladogram presented by Andres et al. (2014) and shows the more basal portion in detail (Eupterodactyloidea has been condensed to a single branch – see Figure 2). The thick branches represent known stratigraphical ranges (based on data in The Paleobiology Database); thin branches represent estimated ghost ranges and connectors used to demarcate phylogenetic relationships. Time-sliced data-sets were derived from this tree by appropriate inclusion/exclusion of taxa. Most stratigraphical stage and taxon abbreviations are listed in the legend of Table 1. Additional abbreviations: CA, Central Asia; CO, Coniacian; EA, East Asia; Eop, Eopterosauria; EU, Europe; Euc, Euctenochasmatia; KI, Kimmeridgian; NA, North America; OX, Oxfordian; RH, Rhaetian; SA (after taxon name), South America; SA (time scale), Santonian; TU, Turonian. pterosaurs applied by Barrett et al.
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