DOCSLIB.ORG

Skeletal Completeness of the Non‐Avian Theropod Dinosaur Fossil

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

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. Oct. 2021 [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
Recommended publications
  • A New Raptorial Dinosaur with Exceptionally Long Feathering Provides Insights Into Dromaeosaurid flight Performance

    A New Raptorial Dinosaur with Exceptionally Long Feathering Provides Insights Into Dromaeosaurid flight Performance

    ARTICLE Received 11 Apr 2014 | Accepted 11 Jun 2014 | Published 15 Jul 2014 DOI: 10.1038/ncomms5382 A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance Gang Han1, Luis M. Chiappe2, Shu-An Ji1,3, Michael Habib4, Alan H. Turner5, Anusuya Chinsamy6, Xueling Liu1 & Lizhuo Han1 Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aero- dynamic capacity. These close relatives of birds are essential for testing hypotheses explaining the origin and early evolution of avian flight. Here we describe a new ‘four-winged’ microraptorine, Changyuraptor yangi, from the Early Cretaceous Jehol Biota of China. With tail feathers that are nearly 30 cm long, roughly 30% the length of the skeleton, the new fossil possesses the longest known feathers for any non-avian dinosaur. Furthermore, it is the largest theropod with long, pennaceous feathers attached to the lower hind limbs (that is, ‘hindwings’). The lengthy feathered tail of the new fossil provides insight into the flight performance of microraptorines and how they may have maintained aerial competency at larger body sizes. We demonstrate how the low-aspect-ratio tail of the new fossil would have acted as a pitch control structure reducing descent speed and thus playing a key role in landing. 1 Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China. 2 Dinosaur Institute, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA. 3 Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China. 4 University of Southern California, Health Sciences Campus, BMT 403, Mail Code 9112, Los Angeles, California 90089, USA.
  • Late Jurassic Theropod Dinosaur Bones from the Langenberg Quarry

    Late Jurassic Theropod Dinosaur Bones from the Langenberg Quarry

    Late Jurassic theropod dinosaur bones from the Langenberg Quarry (Lower Saxony, Germany) provide evidence for several theropod lineages in the central European archipelago Serjoscha W. Evers1 and Oliver Wings2 1 Department of Geosciences, University of Fribourg, Fribourg, Switzerland 2 Zentralmagazin Naturwissenschaftlicher Sammlungen, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany ABSTRACT Marine limestones and marls in the Langenberg Quarry provide unique insights into a Late Jurassic island ecosystem in central Europe. The beds yield a varied assemblage of terrestrial vertebrates including extremely rare bones of theropod from theropod dinosaurs, which we describe here for the first time. All of the theropod bones belong to relatively small individuals but represent a wide taxonomic range. The material comprises an allosauroid small pedal ungual and pedal phalanx, a ceratosaurian anterior chevron, a left fibula of a megalosauroid, and a distal caudal vertebra of a tetanuran. Additionally, a small pedal phalanx III-1 and the proximal part of a small right fibula can be assigned to indeterminate theropods. The ontogenetic stages of the material are currently unknown, although the assignment of some of the bones to juvenile individuals is plausible. The finds confirm the presence of several taxa of theropod dinosaurs in the archipelago and add to our growing understanding of theropod diversity and evolution during the Late Jurassic of Europe. Submitted 13 November 2019 Accepted 19 December 2019 Subjects Paleontology,
  • The Princeton Field Guide to Dinosaurs, Second Edition

    The Princeton Field Guide to Dinosaurs, Second Edition

    MASS ESTIMATES - DINOSAURS ETC (largely based on models) taxon k model femur length* model volume ml x specific gravity = model mass g specimen (modeled 1st):kilograms:femur(or other long bone length)usually in decameters kg = femur(or other long bone)length(usually in decameters)3 x k k = model volume in ml x specific gravity(usually for whole model) then divided/model femur(or other long bone)length3 (in most models femur in decameters is 0.5253 = 0.145) In sauropods the neck is assigned a distinct specific gravity; in dinosaurs with large feathers their mass is added separately; in dinosaurs with flight ablity the mass of the fight muscles is calculated separately as a range of possiblities SAUROPODS k femur trunk neck tail total neck x 0.6 rest x0.9 & legs & head super titanosaur femur:~55000-60000:~25:00 Argentinosaurus ~4 PVPH-1:~55000:~24.00 Futalognkosaurus ~3.5-4 MUCPv-323:~25000:19.80 (note:downsize correction since 2nd edition) Dreadnoughtus ~3.8 “ ~520 ~75 50 ~645 0.45+.513=.558 MPM-PV 1156:~26000:19.10 Giraffatitan 3.45 .525 480 75 25 580 .045+.455=.500 HMN MB.R.2181:31500(neck 2800):~20.90 “XV2”:~45000:~23.50 Brachiosaurus ~4.15 " ~590 ~75 ~25 ~700 " +.554=~.600 FMNH P25107:~35000:20.30 Europasaurus ~3.2 “ ~465 ~39 ~23 ~527 .023+.440=~.463 composite:~760:~6.20 Camarasaurus 4.0 " 542 51 55 648 .041+.537=.578 CMNH 11393:14200(neck 1000):15.25 AMNH 5761:~23000:18.00 juv 3.5 " 486 40 55 581 .024+.487=.511 CMNH 11338:640:5.67 Chuanjiesaurus ~4.1 “ ~550 ~105 ~38 ~693 .063+.530=.593 Lfch 1001:~10700:13.75 2 M.
  • The Origin and Early Evolution of Dinosaurs

    The Origin and Early Evolution of Dinosaurs

    Biol. Rev. (2010), 85, pp. 55–110. 55 doi:10.1111/j.1469-185X.2009.00094.x The origin and early evolution of dinosaurs Max C. Langer1∗,MartinD.Ezcurra2, Jonathas S. Bittencourt1 and Fernando E. Novas2,3 1Departamento de Biologia, FFCLRP, Universidade de S˜ao Paulo; Av. Bandeirantes 3900, Ribeir˜ao Preto-SP, Brazil 2Laboratorio de Anatomia Comparada y Evoluci´on de los Vertebrados, Museo Argentino de Ciencias Naturales ‘‘Bernardino Rivadavia’’, Avda. Angel Gallardo 470, Cdad. de Buenos Aires, Argentina 3CONICET (Consejo Nacional de Investigaciones Cient´ıficas y T´ecnicas); Avda. Rivadavia 1917 - Cdad. de Buenos Aires, Argentina (Received 28 November 2008; revised 09 July 2009; accepted 14 July 2009) ABSTRACT The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis,andPanphagia protos from the Ischigualasto Formation, Argentina, and Staurikosaurus pricei and Saturnalia tupiniquim from the Santa Maria Formation, Brazil. No uncontroversial dinosaur body fossils are known from older strata, but the Middle Triassic origin of the lineage may be inferred from both the footprint record and its sister-group relation to Ladinian basal dinosauromorphs. These include the typical Marasuchus lilloensis, more basal forms such as Lagerpeton and Dromomeron, as well as silesaurids: a possibly monophyletic group composed of Mid-Late Triassic forms that may represent immediate sister taxa to dinosaurs. The first phylogenetic definition to fit the current understanding of Dinosauria as a node-based taxon solely composed of mutually exclusive Saurischia and Ornithischia was given as ‘‘all descendants of the most recent common ancestor of birds and Triceratops’’.
  • Evaluating the Ecology of Spinosaurus: Shoreline Generalist Or Aquatic Pursuit Specialist?

    Evaluating the Ecology of Spinosaurus: Shoreline Generalist Or Aquatic Pursuit Specialist?

    Palaeontologia Electronica palaeo-electronica.org Evaluating the ecology of Spinosaurus: Shoreline generalist or aquatic pursuit specialist? David W.E. Hone and Thomas R. Holtz, Jr. ABSTRACT The giant theropod Spinosaurus was an unusual animal and highly derived in many ways, and interpretations of its ecology remain controversial. Recent papers have added considerable knowledge of the anatomy of the genus with the discovery of a new and much more complete specimen, but this has also brought new and dramatic interpretations of its ecology as a highly specialised semi-aquatic animal that actively pursued aquatic prey. Here we assess the arguments about the functional morphology of this animal and the available data on its ecology and possible habits in the light of these new finds. We conclude that based on the available data, the degree of adapta- tions for aquatic life are questionable, other interpretations for the tail fin and other fea- tures are supported (e.g., socio-sexual signalling), and the pursuit predation hypothesis for Spinosaurus as a “highly specialized aquatic predator” is not supported. In contrast, a ‘wading’ model for an animal that predominantly fished from shorelines or within shallow waters is not contradicted by any line of evidence and is well supported. Spinosaurus almost certainly fed primarily from the water and may have swum, but there is no evidence that it was a specialised aquatic pursuit predator. David W.E. Hone. Queen Mary University of London, Mile End Road, London, E1 4NS, UK. [email protected] Thomas R. Holtz, Jr. Department of Geology, University of Maryland, College Park, Maryland 20742 USA and Department of Paleobiology, National Museum of Natural History, Washington, DC 20560 USA.
  • A New Crested Theropod Dinosaur from the Early Jurassic of Yunnan

    A New Crested Theropod Dinosaur from the Early Jurassic of Yunnan

    第55卷 第2期 古 脊 椎 动 物 学 报 pp. 177-186 2017年4月 VERTEBRATA PALASIATICA figs. 1-3 A new crested theropod dinosaur from the Early Jurassic of Yunnan Province, China WANG Guo-Fu1,2 YOU Hai-Lu3,4* PAN Shi-Gang5 WANG Tao5 (1 Fossil Research Center of Chuxiong Prefecture, Yunnan Province Chuxiong, Yunnan 675000) (2 Chuxiong Prefectural Museum Chuxiong, Yunnan 675000) (3 Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044 * Corresponding author: [email protected]) (4 College of Earth Sciences, University of Chinese Academy of Sciences Beijing 100049) (5 Bureau of Land and Resources of Lufeng County Lufeng, Yunnan 650031) Abstract A new crested theropod, Shuangbaisaurus anlongbaoensis gen. et sp. nov., is reported. The new taxon is recovered from the Lower Jurassic Fengjiahe Formation of Shuangbai County, Chuxiong Yi Autonomous Prefecture, Yunnan Province, and is represented by a partial cranium. Shuangbaisaurus is unique in possessing parasagittal crests along the orbital dorsal rims. It is also distinguishable from the other two lager-bodied parasagittal crested Early Jurassic theropods (Dilophosaurus and Sinosaurus) by a unique combination of features, such as higher than long premaxillary body, elevated ventral edge of the premaxilla, and small upper temporal fenestra. Comparative morphological study indicates that “Dilophosaurus” sinensis could potentially be assigned to Sinosaurus, but probably not to the type species. The discovery of Shuangbaisaurus will help elucidate the evolution of basal theropods, especially the role of various bony cranial ornamentations had played in the differentiation of early theropods.
  • The Adaptations of Antarctic Dinosaurs "Exploration Is the Physical Expression of the Intellectual Passion

    The Adaptations of Antarctic Dinosaurs "Exploration Is the Physical Expression of the Intellectual Passion

    The Adaptations of Antarctic Dinosaurs "Exploration is the physical expression of the Intellectual Passion. And I tell you, if you have the desire for knowledge and the power to give it physical expression, go out and explore. If you are a brave man you will do nothing: if you are fearful you may do much, for none but cowards have need to prove their bravery. Some will tell you that you are mad, and nearly all will say, "What is the use?" For we are a nation of shopkeepers, and no shopkeeper will look at research which does not promise him a financial return within a year. And so you will sledge nearly alone, but those with whom you sledge will not be shopkeepers: that is worth a good deal. If you march your Winter Journeys you will have your reward, so long as all you want is a penguin's egg." —Apsley Cherry-Garrard, "The Worst Journey in the World" Life Long Ago in the Antarctic Long ago during the age of the dinosaurs the basics of life and survival were not so different from today. Life was in great abundance and creatures of all sizes walked, stomped, crept and slunk all over the earth. Although many of the animals have changed and disappeared, the way all animals live have remained the same. They still need to eat, sleep and be safe. They still all strive to find way to raise a family and be happy. This was true even 185 million years ago in the continent we now call Antarctica.
  • A Re-Evaluation of the Enigmatic Dinosauriform Caseosaurus Crosbyensis from the Late Triassic of Texas, USA and Its Implications for Early Dinosaur Evolution

    A Re-Evaluation of the Enigmatic Dinosauriform Caseosaurus Crosbyensis from the Late Triassic of Texas, USA and Its Implications for Early Dinosaur Evolution

    A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution MATTHEW G. BARON and MEGAN E. WILLIAMS Baron, M.G. and Williams, M.E. 2018. A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution. Acta Palaeontologica Polonica 63 (1): 129–145. The holotype specimen of the Late Triassic dinosauriform Caseosaurus crosbyensis is redescribed and evaluated phylogenetically for the first time, providing new anatomical information and data on the earliest dinosaurs and their evolution within the dinosauromorph lineage. Historically, Caseosaurus crosbyensis has been considered to represent an early saurischian dinosaur, and often a herrerasaur. More recent work on Triassic dinosaurs has cast doubt over its supposed dinosaurian affinities and uncertainty about particular features in the holotype and only known specimen has led to the species being regarded as a dinosauriform of indeterminate position. Here, we present a new diagnosis for Caseosaurus crosbyensis and refer additional material to the taxon—a partial right ilium from Snyder Quarry. Our com- parisons and phylogenetic analyses suggest that Caseosaurus crosbyensis belongs in a clade with herrerasaurs and that this clade is the sister taxon of Dinosauria, rather than positioned within it. This result, along with other recent analyses of early dinosaurs, pulls apart what remains of the “traditional” group of dinosaurs collectively termed saurischians into a polyphyletic assemblage and implies that Dinosauria should be regarded as composed exclusively of Ornithoscelida (Ornithischia + Theropoda) and Sauropodomorpha. In addition, our analysis recovers the enigmatic European taxon Saltopus elginensis among herrerasaurs for the first time.
  • Difficulties with the Origin of Dinosaurs: a Short Comment on the Current Debate

    Difficulties with the Origin of Dinosaurs: a Short Comment on the Current Debate

    REVIEW ARTICLE Difficulties with the origin of dinosaurs: a short comment on the current debate MATTHEW G. BARON BPP University, 144 Uxbridge Road, London W12 8AA, UK E-mail: [email protected] Abstract: The origin and early evolutionary history of the dinosaurs is a topic that has recently gone through a period of renewed interest and academic debate. For 130 years, one way of classifying the various dinosaur subgroups persisted as the accepted model, with increasing levels of research in the past quarter-century also providing evidence for the hypothesis that dinosaur origination occurred in the Southern Hemisphere, particularly in South America. It is, after all, from within the Late Triassic strata of countries like Argentina and Brazil that we get some of the very best early dinosaur specimens; many of these specimens are the earliest known representatives of some of the major dinosaur subgroups, such as the theropods and sauropodomorphs. However, some recent analyses have brought about a shift in terms of what is currently accepted and what is now disputed regarding the origin of dinosaurs – the Southern Hemisphere origination hypothesis was questioned (although this was based upon observations and not with quantitative analysis techniques), as has the shape of the dinosaur tree. Responses to the new hypothesis were numerous and robust, and new analyses further supported a Southern Hemisphere point of origin. Whilst the interrelationships between the major dinosaur clades remains to be fully resolved, the current data does seem to comprehensively answer the question of where the dinosaurs first originated. However, it is arguable whether or not the current data that is being used in such palaeobiogeographical analyses is sufficient to provide a meaningful answer to the question of where specifically the dinosaur clade first appeared.
  • The Nonavian Theropod Quadrate II: Systematic Usefulness, Major Trends and Cladistic and Phylogenetic Morphometrics Analyses

    The Nonavian Theropod Quadrate II: Systematic Usefulness, Major Trends and Cladistic and Phylogenetic Morphometrics Analyses

    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/272162807 The nonavian theropod quadrate II: systematic usefulness, major trends and cladistic and phylogenetic morphometrics analyses Article · January 2014 DOI: 10.7287/peerj.preprints.380v2 CITATION READS 1 90 3 authors: Christophe Hendrickx Ricardo Araujo University of the Witwatersrand Technical University of Lisbon 37 PUBLICATIONS 210 CITATIONS 89 PUBLICATIONS 324 CITATIONS SEE PROFILE SEE PROFILE Octávio Mateus University NOVA of Lisbon 224 PUBLICATIONS 2,205 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Nature and Time on Earth - Project for a course and a book for virtual visits to past environments in learning programmes for university students (coordinators Edoardo Martinetto, Emanuel Tschopp, Robert A. Gastaldo) View project Ten Sleep Wyoming Jurassic dinosaurs View project All content following this page was uploaded by Octávio Mateus on 12 February 2015. The user has requested enhancement of the downloaded file. The nonavian theropod quadrate II: systematic usefulness, major trends and cladistic and phylogenetic morphometrics analyses Christophe Hendrickx1,2 1Universidade Nova de Lisboa, CICEGe, Departamento de Ciências da Terra, Faculdade de Ciências e Tecnologia, Quinta da Torre, 2829-516, Caparica, Portugal. 2 Museu da Lourinhã, 9 Rua João Luis de Moura, 2530-158, Lourinhã, Portugal. s t [email protected] n i r P e 2,3,4,5 r Ricardo Araújo P 2 Museu da Lourinhã, 9 Rua João Luis de Moura, 2530-158, Lourinhã, Portugal. 3 Huffington Department of Earth Sciences, Southern Methodist University, PO Box 750395, 75275-0395, Dallas, Texas, USA.
  • Index of Subjects

    Index of Subjects

    Cambridge University Press 978-1-108-47594-5 — Dinosaurs 4th Edition Index More Information INDEX OF SUBJECTS – – – A Zuul, 275 276 Barrett, Paul, 98, 335 336, 406, 446 447 Ankylosauridae Barrick, R, 383–384 acetabulum, 71, 487 characteristics of, 271–273 basal dinosauromorph, 101 acromial process, 271, 273, 487 cladogram of, 281 basal Iguanodontia, 337 actual diversity, 398 defined, 488 basal Ornithopoda, 336 adenosine diphosphate, see ADP evolution of, 279 Bates, K. T., 236, 360 adenosine triphosphate, see ATP ankylosaurids, 275–276 beak, 489 ADP (adenosine diphosphate), 390, 487 anpsids, 76 belief systems, 474, 489 advanced characters, 55, 487 antediluvian period, 422, 488 Bell, P. R., 162 aerobic metabolism, 391, 487 anterior position, 488 bennettitaleans, 403, 489 – age determination (dinosaur), 354 357 antorbital fenestra, 80, 488 benthic organisms, 464, 489 Age of Dinosaurs, 204, 404–405 Arbour, Victoria, 277 Benton, M. J., 2, 104, 144, 395, 402–403, akinetic movement, see kinetic movement Archibald, J. D., 467, 469 444–445, 477–478 Alexander, R. M., 361 Archosauria, 80, 88–90, 203, 488 Berman, D. S, 236–237 allometry, 351, 487 Archosauromorpha, 79–81, 488 Beurien, Karl, 435 altricial offspring, 230, 487 archosauromorphs, 401 bidirectional respiration, 350 Alvarez, Luis, 455 archosaurs, 203, 401 Big Al, 142 – Alvarez, Walter, 442, 454 455, 481 artifacts, 395 biogeography, 313, 489 Alvarezsauridae, 487 Asaro, Frank, 455 biomass, 415, 489 – alvarezsaurs, 168 169 ascending process of the astragalus, 488 biosphere, 2 alveolus/alveoli,
  • New Transitional Fossil from Late Jurassic of Chile Sheds Light on the Origin of Modern Crocodiles Fernando E

    New Transitional Fossil from Late Jurassic of Chile Sheds Light on the Origin of Modern Crocodiles Fernando E

    www.nature.com/scientificreports OPEN New transitional fossil from late Jurassic of Chile sheds light on the origin of modern crocodiles Fernando E. Novas1,2, Federico L. Agnolin1,2,3*, Gabriel L. Lio1, Sebastián Rozadilla1,2, Manuel Suárez4, Rita de la Cruz5, Ismar de Souza Carvalho6,8, David Rubilar‑Rogers7 & Marcelo P. Isasi1,2 We describe the basal mesoeucrocodylian Burkesuchus mallingrandensis nov. gen. et sp., from the Upper Jurassic (Tithonian) Toqui Formation of southern Chile. The new taxon constitutes one of the few records of non‑pelagic Jurassic crocodyliforms for the entire South American continent. Burkesuchus was found on the same levels that yielded titanosauriform and diplodocoid sauropods and the herbivore theropod Chilesaurus diegosuarezi, thus expanding the taxonomic composition of currently poorly known Jurassic reptilian faunas from Patagonia. Burkesuchus was a small‑sized crocodyliform (estimated length 70 cm), with a cranium that is dorsoventrally depressed and transversely wide posteriorly and distinguished by a posteroventrally fexed wing‑like squamosal. A well‑defned longitudinal groove runs along the lateral edge of the postorbital and squamosal, indicative of a anteroposteriorly extensive upper earlid. Phylogenetic analysis supports Burkesuchus as a basal member of Mesoeucrocodylia. This new discovery expands the meagre record of non‑pelagic representatives of this clade for the Jurassic Period, and together with Batrachomimus, from Upper Jurassic beds of Brazil, supports the idea that South America represented a cradle for the evolution of derived crocodyliforms during the Late Jurassic. In contrast to the Cretaceous Period and Cenozoic Era, crocodyliforms from the Jurassic Period are predomi- nantly known from marine forms (e.g., thalattosuchians)1.