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Skeletal Completeness of the Non‐Avian Theropod Dinosaur Fossil

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University of Birmingham Skeletal completeness of the non-avian theropod dinosaur fossil record Cashmore, Daniel; Butler, Richard DOI: 10.1111/pala.12436 License: Creative Commons: Attribution (CC BY) Document Version Publisher's PDF, also known as Version of record Citation for published version (Harvard): Cashmore, D & Butler, R 2019, 'Skeletal completeness of the non-avian theropod dinosaur fossil record', Palaeontology, vol. 62, no. 6, pp. 951-981. https://doi.org/10.1111/pala.12436 Link to publication on Research at Birmingham portal Publisher Rights Statement: Cashmore, D & Butler, R (2019), 'Skeletal completeness of the non-avian theropod dinosaur fossil record', Palaeontology, vol. 62, no. 6, pp. 951-981. © 2019 The Authors 2019. https://doi.org/10.1111/pala.12436 General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive. If you believe that this is the case for this document, please contact [email protected] providing details and we will remove access to the work immediately and investigate. Download date: 01. Mar. 2020 [Palaeontology, 2019, pp. 1–31] SKELETAL COMPLETENESS OF THE NON-AVIAN THEROPOD DINOSAUR FOSSIL RECORD by DANIEL D. CASHMORE and RICHARD J. BUTLER School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK; [email protected] Typescript received 14 January 2019; accepted in revised form 20 April 2019 Abstract: Non-avian theropods were a highly successful conservation Lagerst€atten are excluded, possibly indicating clade of bipedal, predominantly carnivorous, dinosaurs. that both records are primarily driven by geology and sam- Their diversity and macroevolutionary patterns have been pling availability. Our results reveal relatively weak temporal the subject of many studies. Changes in fossil specimen com- sampling biases acting on the theropod record but relatively pleteness through time and space can bias our understanding strong spatial and environmental biases. Asia has a signifi- of macroevolution. Here, we quantify the completeness of cantly more complete record than any other continent, the 455 non-avian theropod species using the skeletal complete- mid northern latitudes have the highest abundance of finds, ness metric (SCM), which calculates the proportion of a and most complete theropod skeletons come from lacustrine complete skeleton preserved for a specimen. Temporal pat- and aeolian environments. We suggest that these patterns terns of theropod skeletal completeness show peaks in the result from historical research focus, modern climate dynam- Carnian, Oxfordian–Kimmeridgian and Barremian–Aptian, ics, and depositional transportation energy plus association and lows in the Berriasian and Hauterivian. Lagerst€atten pri- with conservation Lagerst€atten, respectively. Furthermore, we marily drive the peaks in completeness and observed taxo- find possible ecological biases acting on different theropod nomic diversity in the Oxfordian–Kimmeridgian and the subgroups, but body size does not influence theropod com- Barremian–Aptian. Theropods have a significantly lower dis- pleteness on a global scale. tribution of completeness scores than contemporary sauro- podomorph dinosaurs but change in completeness through Key words: Theropoda, dinosaurs, skeletal, completeness time for the two groups shows a significant correlation when metrics, Lagerst€atten, sampling bias. T HEROPODS are a major clade of bipedal saurischian patterns have received substantial attention (Sereno 1997, dinosaurs. The non-avian species first appeared in the 1999; Carrano 2006; Lloyd et al. 2008, 2016; Brusatte Late Triassic, dispersed and diversified in the Jurassic, et al. 2008a, b; Le Loeuff 2012; Benson & Choiniere 2013; became dominant in predatory guilds (Holtz 2012) and Benson et al. 2014, 2016, 2018; Xu et al. 2014; Sakamoto gave rise to birds (Padian & Chiappe 1998; Xu et al. et al. 2016), with many recent studies attempting to esti- 2014; Brusatte et al. 2015), but ultimately went extinct at mate relative or absolute changes in their diversity the end of the Cretaceous (66 Ma). They were predomi- through time (Barrett et al. 2009; Lloyd 2011; Upchurch nantly carnivorous, but some derived lineages evolved et al. 2011; Brusatte et al. 2014; Starrfelt & Liow 2016; omnivorous and herbivorous diets (Barrett 2005, 2014; Tennant et al. 2018). Zanno & Makovicky 2013; Novas et al. 2015; Lauten- The fossil record has temporal, geographical, environ- schlager 2017). Non-avian theropod fossils have been mental and skeletal gaps (Newell 1959; Foote & Raup found on all continents and in all environments, occupy- 1996; Kidwell & Holland 2002), and it is essential that ing an array of ecological niches (Henderson 1998; Amiot these limitations are considered when making interpreta- et al. 2010; Godefroit et al. 2013; Sales et al. 2016; Laut- tions about the evolutionary patterns of a group. In enschlager 2017; Frederickson et al. 2018), and exhibit recent decades much research has focused on the impact high taxonomic diversity, morphological disparity (Bru- of this incompleteness on our interpretations drawn from satte et al. 2012a, b; Griffin & Nesbitt 2016; Barta et al. the fossil record (e.g. Dingus 1984; Foote & Sepkoski 2018) and body size variation (O’Gorman & Hone 2012; 1999; Benton et al. 2000, 2011; Smith 2001, 2007; Cooper Benson et al. 2014, 2018). Theropods have been one of et al. 2006). Many assessments have focused on the rela- the most intensely studied groups of fossil vertebrates tive proportions of species or species ranges represented (Benton 2008, 2010). Theropod macroevolutionary in the fossil record. This has been assessed by quantifying © 2019 The Authors. doi: 10.1111/pala.12436 1 Palaeontology published by John Wiley & Sons Ltd on behalf of The Palaeontological Association. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 2 PALAEONTOLOGY the extent to which fossil occurrence ranges represent is likely to yield more complete skeletons (Bernard et al. ‘true’ temporal ranges of species (Benton & Storrs 1994, 2010). Incomplete skeletons may also be difficult to diag- 1996; Foote & Raup 1996; Eiting & Gunnell 2009), and nose, resulting in either a reduction in diversity estimates by the level of congruence, or percentage of gaps (ghost for a group or time bin or, conversely, increasing diver- ranges), between the stratigraphical order of fossil occur- sity as a result of taxonomic oversplitting (Brocklehurst & rences and order of phylogenetic tree branching (Dingus Frobisch€ 2014). Previous studies have found varying cor- 1984; Benton & Storrs 1994, 1996; Teeling et al. 2005; relations between completeness metrics and changes in Upchurch & Barrett 2005; Dyke et al. 2009; O’Connor diversity and fossil record sampling metrics through time, et al. 2011a). as well as various geographical and environmental differ- Over the last two decades, many assessments of the qual- ences between the fossil records of different groups (Man- ity of the fossil record have focused on the variation in nion & Upchurch 2010a; Brocklehurst et al. 2012; information content provided by fossil specimens of a Walther & Frobisch€ 2013; Brocklehurst & Frobisch€ 2014; group (Benton et al. 2004; Fountaine et al. 2005; Smith Cleary et al. 2015; Dean et al. 2016; Verriere et al. 2016; 2007; Dyke et al. 2009; Benton 2010; Mannion & Davies et al. 2017; Tutin & Butler 2017; Driscoll et al. Upchurch 2010a; Brocklehurst et al. 2012; Walther & 2018; Brown et al. 2019), thus highlighting major biases Frobisch€ 2013; Brocklehurst & Frobisch€ 2014; Cleary et al. that influence different fossil records to various extents. 2015; Dean et al. 2016; Verriere et al. 2016; Davies et al. Dinosaurs have featured prominently in discussions of 2017; Driscoll et al. 2018; Brown et al. 2019). Using these the quality of the fossil record (Butler & Upchurch 2007; approaches, a high-quality fossil record would be one that Benton 2008, 2010; Lloyd et al. 2008; Barrett et al. 2009; contains many highly complete specimens. Early methods Mannion & Upchurch 2010a; Tarver et al. 2011; Brockle- for quantifying specimen completeness were relatively sub- hurst et al. 2012). Studies have demonstrated that: (1) jective, and scored the completeness of
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  • Kimmeridgian (Late Jurassic) Cold-Water Idoceratids (Ammonoidea) from Southern Coahuila, Northeastern Mexico, Associated with Boreal Bivalves and Belemnites

    Kimmeridgian (Late Jurassic) Cold-Water Idoceratids (Ammonoidea) from Southern Coahuila, Northeastern Mexico, Associated with Boreal Bivalves and Belemnites

    REVISTA MEXICANA DE CIENCIAS GEOLÓGICAS Kimmeridgian cold-water idoceratids associated with Boreal bivalvesv. 32, núm. and 1, 2015, belemnites p. 11-20 Kimmeridgian (Late Jurassic) cold-water idoceratids (Ammonoidea) from southern Coahuila, northeastern Mexico, associated with Boreal bivalves and belemnites Patrick Zell* and Wolfgang Stinnesbeck Institute for Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234, 69120 Heidelberg, Germany. *[email protected] ABSTRACT et al., 2001; Chumakov et al., 2014) was followed by a cool period during the late Oxfordian-early Kimmeridgian (e.g., Jenkyns et al., Here we present two early Kimmeridgian faunal assemblages 2002; Weissert and Erba, 2004) and a long-term gradual warming composed of the ammonite Idoceras (Idoceras pinonense n. sp. and trend towards the Jurassic-Cretaceous boundary (e.g., Abbink et al., I. inflatum Burckhardt, 1906), Boreal belemnites Cylindroteuthis 2001; Lécuyer et al., 2003; Gröcke et al., 2003; Zakharov et al., 2014). cuspidata Sachs and Nalnjaeva, 1964 and Cylindroteuthis ex. gr. Palynological data suggest that the latest Jurassic was also marked by jacutica Sachs and Nalnjaeva, 1964, as well as the Boreal bivalve Buchia significant fluctuations in paleotemperature and climate (e.g., Abbink concentrica (J. de C. Sowerby, 1827). The assemblages were discovered et al., 2001). in inner- to outer shelf sediments of the lower La Casita Formation Upper Jurassic-Lower Cretaceous marine associations contain- at Puerto Piñones, southern Coahuila, and suggest that some taxa of ing both Tethyan and Boreal elements [e.g. ammonites, belemnites Idoceras inhabited cold-water environments. (Cylindroteuthis) and bivalves (Buchia)], were described from numer- ous localities of the Western Cordillera belt from Alaska to California Key words: La Casita Formation, Kimmeridgian, idoceratid ammonites, (e.g., Jeletzky, 1965), while Boreal (Buchia) and even southern high Boreal bivalves, Boreal belemnites.