THE PECTORAL GIRDLE and FORELIMB ANATOMY of the STEM-SAUROPODOMORPH SATURNALIA TUPINIQUIM (UPPER TRIASSIC, BRAZIL) by MAX C

Total Page:16

File Type:pdf, Size:1020Kb

THE PECTORAL GIRDLE and FORELIMB ANATOMY of the STEM-SAUROPODOMORPH SATURNALIA TUPINIQUIM (UPPER TRIASSIC, BRAZIL) by MAX C [Special Papers in Palaeontology 77, 2007, pp. 113–137] THE PECTORAL GIRDLE AND FORELIMB ANATOMY OF THE STEM-SAUROPODOMORPH SATURNALIA TUPINIQUIM (UPPER TRIASSIC, BRAZIL) by MAX C. LANGER*, MARCO A. G. FRANC¸A* and STEFAN GABRIEL *FFCLRP, Universidade de Sa˜o Paulo (USP), Av. Bandeirantes, 3900, Ribeira˜o Preto 14040–901, SP, Brazil; e-mails: [email protected]; [email protected] School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK; e-mail: [email protected] Typescript received 24 February 2006; accepted in revised form 27 October 2006 Abstract: Description of the pectoral girdle (scapulocora- Although less clear than previously suggested, some traits coid) and forelimb (humerus, radius and ulna) elements of S. tupiniquim, such as a long deltopectoral crest and a of two specimens of Saturnalia tupiniquim, a stem-sauro- broad distal humeral end, are indicative of its sauropodo- podomorph from the Upper Triassic Santa Maria For- morph affinity. The taxon also bears several features previ- mation, southern Brazil, reveals a distinctive set of ously regarded as autapomorphic of Herrerasaurus plesiomorphic, derived and unique traits, which shed light ischigualastensis, alluding to their broader distribution on the function and phylogenetic significance of these skel- among basal dinosaurs. Variations within S. tupiniquim are etal elements within early dinosaurs. Autapomorphic fea- mainly robustness-related and do not necessarily imply tures of S. tupiniquim include, among others, an unusually taxonomic distinctions. long olecranon process of the ulna. Its function is still unclear, but it might have helped to sustain a quadrupedal Key words: Saturnalia tupiniquim, Dinosauria, Brazil, Trias- gait, as inferred from the structure of the entire forearm. sic, pectoral girdle, forelimb, anatomy. THE shoulder girdle and forelimb osteology of early tupiniquim is available (Langer 2003). Among the other dinosaurs is poorly known. Apart from the relatively elements resulting from preparation of two of the skele- abundant material referred to Herrerasaurus ischiguala- tons are partial shoulder girdles and forelimbs, which are stensis (Reig 1963; Novas 1986; Brinkman and Sues 1987; the subject of the present contribution. Sereno 1993), and the still undescribed skeleton of Eorap- Until now, because of the abundance of its material, tor lunensis (Sereno et al. 1993), most of the reported Herrerasaurus has been the main basis on which the remains are incomplete. A nearly complete scapulocora- anatomy of the shoulder girdle and forelimb of basal coid is part of the holotype of Guaibasaurus candelariensis dinosaurs was assessed. The constraint of using the con- (Bonaparte et al. 1999), but only scapula fragments and a dition in a single taxon, with its own set of derived and dubious proximal humerus were assigned to Staurikosau- unique features, as almost the sole window on the ples- rus pricei (Galton 2000; Bittencourt 2004). Within other iomorphic anatomy of a clade as diverse as the Dinosau- putative Triassic dinosaurs, incomplete scapula and fore- ria might lead to significant biases. The data available limb elements are among the material referred to Saltopus for S. tupiniquim is believed to alleviate this bias, adding elginensis (von Huene 1910), Spondylosoma absconditum morphological diversity to produce a better picture of (Galton 2000) and Agnosphitys cromhallensis (Fraser et al. the general anatomy of the shoulder girdle and forelimb 2002). of basal dinosaurs in general, and basal saurischians in In the austral summer of 1998, fieldwork conducted by particular. the Museu de Cieˆncias e Tecnologia, Pontifı´cia Universi- dade Cato´lica do Rio Grande do Sul, collected three partial Institutional abbreviations. BMNH, the Natural History Museum, skeletons of a basal dinosaur in the red mudstone that London, UK; MACN, Museo Argentino de Ciencias Naturales typically crops out on the outskirts of Santa Maria (Text- ‘Bernardino Rivadavia’, Buenos Aires, Argentina; MB, Museum fig. 1), in south Brazil (Langer et al. 1999; Langer 2005a). fu¨r Naturkunde, Berlin, Germany; MCN, Fundac¸a˜o Zoobotaˆnica The material is only partially prepared, but a comprehen- do Rio Grande do Sul, Porto Alegre, Brazil; MCP, Museu de Cieˆncias e Tecnologia PUCRS, Porto Alegre, Brazil; PVL, sive description of the pelvis and hindlimb of Saturnalia ª The Palaeontological Association 113 114 SPECIAL PAPERS IN PALAEONTOLOGY, 77 TEXT-FIG. 1. Map showing the fossil-bearing sites on the eastern outskirts of Santa Maria, Rio Grande do Sul, Brazil. Shaded parts indicate urban areas. GS: ‘Grossesanga’, type locality of Staurikosaurus pricei Colbert, 1970; WS: ‘Waldsanga’, type locality of Saturnalia tupiniquim. Fundacı´on Miguel Lillo, Tucuma´n, Argentina; PVSJ, Museo de Ciencias Naturales, San Juan, Argentina; QG, National Museum of Natural History, Harare, Zimbabwe; SMNS, Staatlisches Museum fu¨r Naturkunde, Stuttgart, Germany. MATERIAL AND METHODS 45° The shoulder girdle and forelimb elements of the holo- 110° type of Saturnalia tupiniquim (MCP 3844-PV) include a nearly complete right scapulocoracoid, humerus and radius, and a right ulna lacking its distal third. Additional material belongs to one of the paratypes (MCP 3845-PV), 140° and includes two nearly complete scapulocoracoids, a 100° partial right humerus and the proximal portion of the right ulna. No carpals, metacarpals or phalanges have been recovered, and there is also no trace of any of the dermal elements of the shoulder girdle. If not explicitly TEXT-FIG. 2. Saturnalia tupiniquim, Santa Maria Formation, mentioned, the described features and elements are shared Rio Grande do Sul, Brazil. Lateral view of the right pectoral by both specimens. girdle and partial forelimb reconstructed based mainly on MCP Directional and positional terms used herein are those 3844-PV. Bones assembled in two different poses, corresponding defined in Clark (1993) and the dinosaur compendium of to maximum angles of limb retraction and forearm extension, Weishampel et al. (2004). Considering the rather uncer- and limb protraction and forearm flexion. Shaded (see-through) tain, although most probably oblique (Colbert 1989), area represents the missing distal part of the ulna, and orientation of the shoulder girdle in basal dinosaurs scapulocoracoid long axis is at an angle of about 25 degrees to (Text-fig. 2), it is treated as vertical for descriptive purpo- the horizontal. ses (Nicholls and Russell 1985). Accordingly, the coracoid lies ventral to its articulation with the scapula, whereas (Romer 1966; Coombs 1978; Gauthier 1986). Regarding the scapula blade expands dorsally. This orientation is the forelimb, the arm and forearm are described with chosen, rather than one that more closely reflects avian their long axes orientated vertically (Sereno 1993), and anatomy (Ostrom 1974), because it is plesiomorphic for with the long axis of the elbow joint being orthogonal to archosaurs (Romer 1956) and also more traditional the sagittal plane. This does not reflect their natural posi- LANGER ET AL.: PECTORAL GIRDLE AND FORELIMB OF SATURNALIA TUPINIQUIM 115 tion (see Text-fig. 2), but should render the description SYSTEMATIC PALAEONTOLOGY easier to follow. Hence, the deltopectoral crest expands cranially from the humerus and the forearm moves cau- DINOSAURIA Owen, 1842 dally during extension. SAURISCHIA Seeley, 1887 The remains of S. tupiniquim are well preserved (Lan- EUSAURISCHIA Padian, Hutchinson and Holtz,1999 ger 2003) and lack evidence of major taphonomic distor- stem SAUROPODOMORPHA von Huene, 1932 tions. This allows the recognition of various osteological traces left by the attachments of major muscle groups, Genus SATURNALIA Langer, Abdala, Richter and and some insights on pectoral girdle and limb myology Benton,1999 are presented here (Text-fig. 3). The tentative identifica- tion of the musculature corresponding to these traces Saturnalia tupiniquim Langer, Abdala, Richter and Benton, represents inferences based on a ‘phylogenetic bracket’ 1999 approach (Felsenstein 1985; Bryant and Russell 1992; Wit- Text-figures 2–9, Tables 1–3 mer 1995; Hutchinson 2001). Crocodiles and birds are evidently the main elements of comparison, because they Referred specimens. The type series is composed of the holotype are the only extant archosaurs and the closest living rela- (MCP 3844-PV) and two paratypes (MCP 3845-PV and 3846- tives of S. tupiniquim. PV) (Langer 2003). A BCD H EF I G J TEXT-FIG. 3. Saturnalia tupiniquim, Santa Maria Formation, Rio Grande do Sul, Brazil. Muscle attachment areas on A–B, right scapulocopracoid, C–F, humerus, G–H, partial ulna, I, radius, and J, distal part of radius, reconstructed based mainly on MCP 3844- PV, in lateral (A, C, G, J), medial (B, E, H–I), caudal (D), and cranial (F) views. Light shading indicates areas of muscle origin and dark shading their insertion areas. b., biceps; br., brachialis; cbr.b.d., coracobrachialis brevis pars dorsalis; cbr.b.v., coracobrachialis brevis pars ventralis; cbr.l., coracobrachialis longus; delt.s., deltoideous scapularis; delt.s.i., deltoideous scapularis inferior; e.c.r., extensor carpi radialis; e.c.u., extensor carpi ulnaris; e.d.c., extensor digitorum communis; f.c.u., flexor carpi ulnaris; f.d.l., flexor digitorum longus; f.u., flexor ulnaris; h., humeroradialis; l.d. latissimus dorsi; p. pectoralis; pr.q., pronator quadratus; s., supinator; sc., supracoracoideus; sbs., subscapularis; sh.a., scapulohumeralis
Recommended publications
  • CPY Document
    v^ Official Journal of the Biology Unit of the American Topical Association 10 Vol. 40(4) DINOSAURS ON STAMPS by Michael K. Brett-Surman Ph.D. Dinosaurs are the most popular animals of all time, and the most misunderstood. Dinosaurs did not fly in the air and did not live in the oceans, nor on lake bottoms. Not all large "prehistoric monsters" are dinosaurs. The most famous NON-dinosaurs are plesiosaurs, moso- saurs, pelycosaurs, pterodactyls and ichthyosaurs. Any name ending in 'saurus' is not automatically a dinosaur, for' example, Mastodonto- saurus is neither a mastodon nor a dinosaur - it is an amphibian! Dinosaurs are defined by a combination of skeletal features that cannot readily be seen when the animal is fully restored in a flesh reconstruction. Because of the confusion, this compilation is offered as a checklist for the collector. This topical list compiles all the dinosaurs on stamps where the actual bones are pictured or whole restorations are used. It excludes footprints (as used in the Lesotho stamps), cartoons (as in the 1984 issue from Gambia), silhouettes (Ascension Island # 305) and unoffi- cial issues such as the famous Sinclair Dinosaur stamps. The name "Brontosaurus", which appears on many stamps, is used with quotation marks to denote it as a popular name in contrast to its correct scientific name, Apatosaurus. For those interested in a detailed encyclopedic work about all fossils on stamps, the reader is referred to the forthcoming book, 'Paleontology - a Guide to the Postal Materials Depicting Prehistoric Lifeforms' by Fran Adams et. al. The best book currently in print is a book titled 'Dinosaur Stamps of the World' by Baldwin & Halstead.
    [Show full text]
  • The Braincase, Brain and Palaeobiology of the Basal Sauropodomorph Dinosaur Thecodontosaurus Antiquus
    applyparastyle “fig//caption/p[1]” parastyle “FigCapt” Zoological Journal of the Linnean Society, 2020, XX, 1–22. With 10 figures. Downloaded from https://academic.oup.com/zoolinnean/advance-article/doi/10.1093/zoolinnean/zlaa157/6032720 by University of Bristol Library user on 14 December 2020 The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus ANTONIO BALLELL1,*, J. LOGAN KING1, JAMES M. NEENAN2, EMILY J. RAYFIELD1 and MICHAEL J. BENTON1 1School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK 2Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK Received 27 May 2020; revised 15 October 2020; accepted for publication 26 October 2020 Sauropodomorph dinosaurs underwent drastic changes in their anatomy and ecology throughout their evolution. The Late Triassic Thecodontosaurus antiquus occupies a basal position within Sauropodomorpha, being a key taxon for documenting how those morphofunctional transitions occurred. Here, we redescribe the braincase osteology and reconstruct the neuroanatomy of Thecodontosaurus, based on computed tomography data. The braincase of Thecodontosaurus shares the presence of medial basioccipital components of the basal tubera and a U-shaped basioccipital–parabasisphenoid suture with other basal sauropodomorphs and shows a distinct combination of characters: a straight outline of the braincase floor, an undivided metotic foramen, an unossified gap, large floccular fossae, basipterygoid processes perpendicular to the cultriform process in lateral view and a rhomboid foramen magnum. We reinterpret these braincase features in the light of new discoveries in dinosaur anatomy. Our endocranial reconstruction reveals important aspects of the palaeobiology of Thecodontosaurus, supporting a bipedal stance and cursorial habits, with adaptations to retain a steady head and gaze while moving.
    [Show full text]
  • Journal of Vertebrate Paleontology Braincase Of
    This article was downloaded by: [Society of Vertebrate Paleontology ] On: 06 November 2013, At: 23:27 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 Journal of Vertebrate Paleontology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ujvp20 Braincase of Panphagia protos (Dinosauria, Sauropodomorpha) Ricardo N. Martínez a , José A. Haro a & Cecilia Apaldetti a b a Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan , 5400 , San Juan , Argentina b Consejo Nacional de Investigaciones Científicas y Técnicas , Buenos Aires , Argentina Published online: 08 Oct 2013. To cite this article: Ricardo N. Martínez , José A. Haro & Cecilia Apaldetti (2012) Braincase of Panphagia protos (Dinosauria, Sauropodomorpha), Journal of Vertebrate Paleontology, 32:sup1, 70-82, DOI: 10.1080/02724634.2013.819009 To link to this article: http://dx.doi.org/10.1080/02724634.2013.819009 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. However, 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. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.
    [Show full text]
  • Studies on Continental Late Triassic Tetrapod Biochronology. I. the Type Locality of Saturnalia Tupiniquim and the Faunal Succession in South Brazil
    Journal of South American Earth Sciences 19 (2005) 205–218 www.elsevier.com/locate/jsames Studies on continental Late Triassic tetrapod biochronology. I. The type locality of Saturnalia tupiniquim and the faunal succession in south Brazil Max Cardoso Langer* Departamento de Biologia, FFCLRP, Universidade de Sa˜o Paulo (USP), Av. Bandeirantes 3900, 14040-901 Ribeira˜o Preto, SP, Brazil Received 1 November 2003; accepted 1 January 2005 Abstract Late Triassic deposits of the Parana´ Basin, Rio Grande do Sul, Brazil, encompass a single third-order, tetrapod-bearing sedimentary sequence that includes parts of the Alemoa Member (Santa Maria Formation) and the Caturrita Formation. A rich, diverse succession of terrestrial tetrapod communities is recorded in these sediments, which can be divided into at least three faunal associations. The stem- sauropodomorph Saturnalia tupiniquim was collected in the locality known as ‘Waldsanga’ near the city of Santa Maria. In that area, the deposits of the Alemoa Member yield the ‘Alemoa local fauna,’ which typifies the first association; includes the rhynchosaur Hyperodapedon, aetosaurs, and basal dinosaurs; and is coeval with the lower fauna of the Ischigualasto Formation, Bermejo Basin, NW Argentina. The second association is recorded in deposits of both the Alemoa Member and the Caturrita Formation, characterized by the rhynchosaur ‘Scaphonyx’ sulcognathus and the cynodont Exaeretodon, and correlated with the upper fauna of the Ischigualasto Formation. Various isolated outcrops of the Caturrita Formation yield tetrapod fossils that correspond to post-Ischigualastian faunas but might not belong to a single faunal association. The record of the dicynodont Jachaleria suggests correlations with the lower part of the Los Colorados Formation, NW Argentina, whereas remains of derived tritheledontid cynodonts indicate younger ages.
    [Show full text]
  • 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.
    [Show full text]
  • Download the Article
    A couple of partially-feathered creatures about the The Outside Story size of a turkey pop out of a stand of ferns. By the water you spot a flock of bigger animals, lean and predatory, catching fish. And then an even bigger pair of animals, each longer than a car, with ostentatious crests on their heads, stalk out of the heat haze. The fish-catchers dart aside, but the new pair have just come to drink. We can only speculate what a walk through Jurassic New England would be like, but the fossil record leaves many hints. According to Matthew Inabinett, one of the Beneski Museum of Natural History’s senior docents and a student of vertebrate paleontology, dinosaur footprints found in the sedimentary rock of the Connecticut Valley reveal much about these animals and their environment. At the time, the land that we know as New England was further south, close to where Cuba is now. A system of rift basins that cradled lakes ran right through our region, from North Carolina to Nova Scotia. As reliable sources of water, with plants for the herbivores and fish for the carnivores, the lakes would have been havens of life. While most of the fossil footprints found in New England so far are in the lower Connecticut Valley, Dinosaur Tracks they provide a window into a world that extended throughout the region. According to Inabinett, the By: Rachel Marie Sargent tracks generally fall into four groupings. He explained that these names are for the tracks, not Imagine taking a walk through a part of New the dinosaurs that made them, since, “it’s very England you’ve never seen—how it was 190 million difficult, if not impossible, to match a footprint to a years ago.
    [Show full text]
  • 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’’.
    [Show full text]
  • The Sauropodomorph Biostratigraphy of the Elliot Formation of Southern Africa: Tracking the Evolution of Sauropodomorpha Across the Triassic–Jurassic Boundary
    Editors' choice The sauropodomorph biostratigraphy of the Elliot Formation of southern Africa: Tracking the evolution of Sauropodomorpha across the Triassic–Jurassic boundary BLAIR W. MCPHEE, EMESE M. BORDY, LARA SCISCIO, and JONAH N. CHOINIERE McPhee, B.W., Bordy, E.M., Sciscio, L., and Choiniere, J.N. 2017. The sauropodomorph biostratigraphy of the Elliot Formation of southern Africa: Tracking the evolution of Sauropodomorpha across the Triassic–Jurassic boundary. Acta Palaeontologica Polonica 62 (3): 441–465. The latest Triassic is notable for coinciding with the dramatic decline of many previously dominant groups, followed by the rapid radiation of Dinosauria in the Early Jurassic. Among the most common terrestrial vertebrates from this time, sauropodomorph dinosaurs provide an important insight into the changing dynamics of the biota across the Triassic–Jurassic boundary. The Elliot Formation of South Africa and Lesotho preserves the richest assemblage of sauropodomorphs known from this age, and is a key index assemblage for biostratigraphic correlations with other simi- larly-aged global terrestrial deposits. Past assessments of Elliot Formation biostratigraphy were hampered by an overly simplistic biozonation scheme which divided it into a lower “Euskelosaurus” Range Zone and an upper Massospondylus Range Zone. Here we revise the zonation of the Elliot Formation by: (i) synthesizing the last three decades’ worth of fossil discoveries, taxonomic revision, and lithostratigraphic investigation; and (ii) systematically reappraising the strati- graphic provenance of important fossil locations. We then use our revised stratigraphic information in conjunction with phylogenetic character data to assess morphological disparity between Late Triassic and Early Jurassic sauropodomorph taxa. Our results demonstrate that the Early Jurassic upper Elliot Formation is considerably more taxonomically and morphologically diverse than previously thought.
    [Show full text]
  • 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.
    [Show full text]
  • Massospondylus Carinatus Owen 1854 (Dinosauria: Sauropodomorpha) from the Lower Jurassic of South Africa: Proposed Conservation of Usage by Designation of a Neotype
    Massospondylus carinatus Owen 1854 (Dinosauria: Sauropodomorpha) from the Lower Jurassic of South Africa: Proposed conservation of usage by designation of a neotype Adam M. Yates1* & Paul M. Barrett2 1Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Private Bag 3, WITS, 2050 Johannesburg, South Africa 2Department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, U.K. Received 17 February 2010. Accepted 12 November 2010 The purpose of this article is to preserve the usage of the binomen Massospondylus carinatus by designating a neotype specimen. Massospondylus is the most abundant basal sauropodomorph dinosaur from the Early Jurassic strata of southern Africa. This taxon forms the basis for an extensive palaeobiological literature and is the eponym of Massospondylidae and the nominal taxon of a biostratigraphical unit in current usage, the ‘Massospondylus Range Zone’. The syntype series of M. carinatus (five disarticulated and broken vertebrae) was destroyed during World War II, but plaster casts and illustrations of the material survive. Nonetheless, these materials cannot act as type material for this taxon under the rules of the ICZN Code. In order to avoid nomenclatural instability, we hereby designate BP/1/4934 (a skull and largely complete postcranial skeleton) as the neotype of Massospondylus carinatus. Keywords: Dinosauria, Sauropodomorpha, Massospondylidae, Massospondylus, Massospondylus carinatus, neotype, South Africa, upper Elliot Formation, Early Jurassic. INTRODUCTION same taxon, possibly even the same individual, as at least Richard Owen described and named Massospondylus some of the syntype series of Massospondylus carinatus. carinatus (1854, p. 97) with carinatus as the type species of Their initial separation from Massospondylus carinatus the genus by monotypy.
    [Show full text]
  • The Anatomy and Phylogenetic Relationships of Antetonitrus Ingenipes (Sauropodiformes, Dinosauria): Implications for the Origins of Sauropoda
    THE ANATOMY AND PHYLOGENETIC RELATIONSHIPS OF ANTETONITRUS INGENIPES (SAUROPODIFORMES, DINOSAURIA): IMPLICATIONS FOR THE ORIGINS OF SAUROPODA Blair McPhee A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2013 i ii ABSTRACT A thorough description and cladistic analysis of the Antetonitrus ingenipes type material sheds further light on the stepwise acquisition of sauropodan traits just prior to the Triassic/Jurassic boundary. Although the forelimb of Antetonitrus and other closely related sauropododomorph taxa retains the plesiomorphic morphology typical of a mobile grasping structure, the changes in the weight-bearing dynamics of both the musculature and the architecture of the hindlimb document the progressive shift towards a sauropodan form of graviportal locomotion. Nonetheless, the presence of hypertrophied muscle attachment sites in Antetonitrus suggests the retention of an intermediary form of facultative bipedality. The term Sauropodiformes is adopted here and given a novel definition intended to capture those transitional sauropodomorph taxa occupying a contiguous position on the pectinate line towards Sauropoda. The early record of sauropod diversification and evolution is re- examined in light of the paraphyletic consensus that has emerged regarding the ‘Prosauropoda’ in recent years. iii ACKNOWLEDGEMENTS First, I would like to express sincere gratitude to Adam Yates for providing me with the opportunity to do ‘real’ palaeontology, and also for gladly sharing his considerable knowledge on sauropodomorph osteology and phylogenetics. This project would not have been possible without the continued (and continual) support (both emotionally and financially) of my parents, Alf and Glenda McPhee – Thank you.
    [Show full text]
  • Postcranial Skeletal Pneumaticity in Sauropods and Its
    Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung by Mathew John Wedel B.S. (University of Oklahoma) 1997 A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Integrative Biology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Kevin Padian, Co-chair Professor William Clemens, Co-chair Professor Marvalee Wake Professor David Wake Professor John Gerhart Spring 2007 1 The dissertation of Mathew John Wedel is approved: Co-chair Date Co-chair Date Date Date Date University of California, Berkeley Spring 2007 2 Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung © 2007 by Mathew John Wedel 3 Abstract Postcranial Pneumaticity in Dinosaurs and the Origin of the Avian Lung by Mathew John Wedel Doctor of Philosophy in Integrative Biology University of California, Berkeley Professor Kevin Padian, Co-chair Professor William Clemens, Co-chair Among extant vertebrates, postcranial skeletal pneumaticity is present only in birds. In birds, diverticula of the lungs and air sacs pneumatize specific regions of the postcranial skeleton. The relationships among pulmonary components and the regions of the skeleton that they pneumatize form the basis for inferences about the pulmonary anatomy of non-avian dinosaurs. Fossae, foramina and chambers in the postcranial skeletons of pterosaurs and saurischian dinosaurs are diagnostic for pneumaticity. In basal saurischians only the cervical skeleton is pneumatized. Pneumatization by cervical air sacs is the most consilient explanation for this pattern. In more derived sauropods and theropods pneumatization of the posterior dorsal, sacral, and caudal vertebrae indicates that abdominal air sacs were also present.
    [Show full text]