DOCSLIB.ORG

By Monica Hughes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
By Monica Hughes by Monica Hughes DinoWorld_covers.indd 2 6/18/07 3:36:41 PM [Intentionally Left Blank] Swimming Giants by Monica Hughes Consultant: Luis M. Chiappe, Ph.D. Director of the Dinosaur Institute Natural History Museum of Los Angeles County 1415_SwimmingGiants_FINAL.indd 1 6/13/07 12:12:53 PM Credits Cover, Title Page, 14–15, 16–17, 24: Luis Rey; 4–5: John Alston; 5, 6, 12–13, 19, 20–21, 23B: Simon Mendez; 7, 8, 9, 10–11, 18, 22, 23M, 23T: Shutterstock. Every effort has been made by ticktock Entertainment Ltd. to trace copyright holders. We apologize in advance for any omissions. We would be pleased to insert the appropriate acknowledgments in any subsequent edition of this publication. Library of Congress Cataloging-in-Publication Data Hughes, Monica. Swimming giants / by Monica Hughes. p. cm. — (I love reading. Dino world!) Includes bibliographical references and index. ISBN-13: 978-1-59716-542-6 (library binding) ISBN-10: 1-59716-542-5 (library binding) 1. Marine reptiles, Fossil—Juvenile literature. 2. Marine animals, Fossil—Juvenile literature. 3. Paleontology—Juvenile literature. I. Title. QE861.5.H846 2008 567.9’37—dc22 2007017958 Copyright © 2007 ticktock Entertainment Ltd. 2 Orchard Business Centre, North Farm Road, Tunbridge Wells, Kent, TN2 3XF, UK Published in the United States of America by Bearport Publishing Company, Inc. United States text copyright © 2008 Bearport Publishing Company, Inc. No part of this publication may be reproduced, in whole or in part, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise without prior written permission from the publisher. For more information, write to Bearport Publishing Company, Inc., 101 Fifth Avenue, Suite 6R, New York, New York 10003. Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1 1415_SwimmingGiants_FINAL.indd 2 6/26/07 4:38:21 PM Contents Swimming giants . 4 Kronosaurus . 6 Placodus . 8 Elasmosaurus . 10 Nothosaurus . 12 Cryptoclidus. 14 Ichthyosaurus . 16 Shonisaurus. 18 Tylosaurus . 20 Glossary . 22 Index . 24 Read More . 24 Learn More Online . 24 1415_SwimmingGiants_FINAL.indd 3 6/13/07 12:12:59 PM Swimming giants Many animals lived at the same time as dinosaurs. Some of these animals lived in water. Ceresiosaurus (ser-ree-see-oh-SOR-uhss) 4 1415_SwimmingGiants_FINAL.indd 4 6/13/07 12:12:59 PM Many of them had very sharp teeth. They used their teeth to catch fi sh and other animals. 5 1415_SwimmingGiants_FINAL.indd 5 6/13/07 12:13:01 PM Kronosaurus (kroh-noh-SOR-uhss) This swimmer grew to about 30 feet (9 m) long. It was about the size of a power boat. 6 1415_SwimmingGiants_FINAL.indd 6 6/13/07 12:13:03 PM Its teeth were as big as bananas. Kronosaurus ate squid and octopuses. squid octopus 7 1415_SwimmingGiants_FINAL.indd 7 6/26/07 3:17:47 PM Index Cryptoclidus 14–15 Nothosaurus 12–13 Elasmosaurus 10–11 Placodus 8–9 Ichthyosaurus 16–17 Shonisaurus 18–19, 20 Kronosaurus 6–7 Tylosaurus 20–21 Read More Lessem, Don. Sea Taylor, Barbara. Oxford Giants of Dinosaur Time. First Book of Dinosaurs. Minneapolis, MN: Lerner New York: Oxford Publications (2005). University Press (2001). Learn More Online To learn more about the world of dinosaurs, visit www.bearportpublishing.com/ILoveReading 24 1415_SwimmingGiants_FINAL.indd 24 6/13/07 12:13:52 PM [Intentionally Left Blank] Swimming Giants Amazing Dinosaur Facts Dinosaur Babies Many animals lived at the same time as dinosaurs. Instead of Dinosaur Fossils roaming the land, however, Dinosaur Hunting some of these animals lived in water. Look inside to learn how Fighting Dinosaurs these swimming giants hunted and survived in the sea. Flying Giants Really Big Dinosaurs and Other Giants Swimming Giants DinoWorld_covers.indd 2 6/18/07 3:36:41 PM.
Load more

Recommended publications
  • Cranial Anatomy, Taxonomic Implications
    [Palaeontology, Vol. 55, Part 4, 2012, pp. 743–773] CRANIAL ANATOMY, TAXONOMIC IMPLICATIONS AND PALAEOPATHOLOGY OF AN UPPER JURASSIC PLIOSAUR (REPTILIA: SAUROPTERYGIA) FROM WESTBURY, WILTSHIRE, UK by JUDYTH SASSOON1, LESLIE F. NOE` 2 and MICHAEL J. BENTON1* 1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, UK; e-mails: [email protected], [email protected] 2Geociencias, departamento de Fisica, Universidad de los Andes, Bogota´ DC, Colombia; e-mail: [email protected] *Corresponding author. Typescript received 5 December 2010; accepted in revised form 6 April 2011 Abstract: Complete skulls of giant marine reptiles of the genera. The two Westbury Pliosaurus specimens share many Late Jurassic are rare, and so the discovery of the 1.8-m- features, including the form of the teeth, but marked differ- long skull of a pliosaur from the Kimmeridge Clay Forma- ences in the snout and parietal crest suggest sexual dimor- tion (Kimmeridgian) of Westbury, Wiltshire, UK, is an phism; the present specimen is probably female. The large important find. The specimen shows most of the cranial size of the animal, the extent of sutural fusion and the and mandibular anatomy, as well as a series of pathological pathologies suggest this is an ageing individual. An erosive conditions. It was previously referred to Pliosaurus brachy- arthrotic condition of the articular glenoids led to pro- spondylus, but it can be referred reliably only to the genus longed jaw misalignment, generating a suite of associated Pliosaurus, because species within the genus are currently in bone and dental pathologies.
    [Show full text]
  • O'keefe, F. R. 2006
    12 Neoteny and the Plesiomorphic Condition of the Plesiosaur Basicranium F. Robin O’Keefe Introduction Historically, the systematics of the Plesiosauria (Reptilia, Sauroptery- gia) were based largely on postcranial characters (Persson, 1963; Brown, 1981). Several factors account for this bias: plesiosaur skulls tend to be del- icate and are often crushed even when preserved, postcranial elements are relatively common and cranial elements are not, lack of knowledge about the relationships of stem-group sauropterygians, and lack of knowledge of plesiosaur cranial anatomy itself. However, recent detailed examinations of plesiosaur cranial anatomy have identified many characters of use in plesiosaur systematics (Brown, 1993; Cruickshank, 1994; Storrs & Taylor, 1996; Storrs, 1997; Carpenter, 1997; Evans, 1999; O’Keefe, 2001, 2004), and the systematics of the group have changed markedly in response (Carpenter, 1997; O’Keefe, 2001, 2004). The work of Rieppel and others has clarified the anatomy and relationships of stem-group sauropterygians (Storrs, 1991; see Rieppel, 2000, for review). This work has laid the anatomic and phylogenetic foundations for a better understanding of ple- siosaur cranial anatomy. The purpose of this paper is to describe the condition of the braincase in stratigraphically early and morphologically primitive plesiosaurs. In- formation on the braincase of plesiomorphic taxa is important because it establishes the polarity of characters occurring in more derived ple- siosaurs. This paper begins with a short review of braincase anatomy in stem-group sauropterygians. Data on braincase morphology of the ple- siomorphic plesiosaur genera Thalassiodracon and Eurycleidus are then presented and interpreted via comparison with other plesiosaurs, stem- group sauropterygians, and stem diapsids (Araeoscelis).
    [Show full text]
  • Carpenter 1999 EL PLESIOSAURIO DE VILLA DE LEYVA (BOYACÁ, COLOMBIA)
    Boletín de Geología Vol. 23, No. 38, Enero-Junio de 2001 Callawayasaurus colombiensis (Welles) Carpenter 1999 EL PLESIOSAURIO DE VILLA DE LEYVA (BOYACÁ, COLOMBIA). ¿UN NUEVO ESPÉCIMEN? Jerez Jaimes, J. H1.; Narváez Parra, E. X1. RESUMEN En los depósitos del Cretácico (Aptiano) de Villa de Leyva se han reportado dos especies de plesiosaurios, un pliosaurio Kronosaurus boyacensis Hampe 1992, y un plesiosaurio Callawayasaurus colombiensis (Welles) Carpenter, 1999 (= Alzadasaurus colombiensis Welles, 1962). Se realiza la determinación de un espécimen de elasmosaurio encontrado por los pobladores de la zona rural de Villa de Leyva en 1999 con base en material fotográfico del mismo, siendo muy probable que corresponda a la especie Callawayasaurus colombiensis (Welles) Carpenter, 1999. Palabras Claves: Cretácico, Plesiosaurios, Villa de Leyva. ABSTRACT In the deposits of the Cretaceous (Aptian) of Villa de Leyva two plesiosaurs species have been reported, a pliosaur Kronosaurus boyacensis Hampe 1992, and a plesiosaur Callawayasaurus colombiensis (Welles) Carpenter, 1999 (= Alzadasaurus colombiensis Welles, 1962). We carried out the determination of elasmosaur specimen found by the inhabitants of the rural area of Villa de Leyva in 1999, on the basis of photographic material of it. Probably it corresponds to the Callawayasaurus colombiensis specie (Welles) Carpenter, 1999. Key Words: Cretaceous, Plesiosaurs, Villa de Leyva. 1Biólogos, Calle 10A # 24-68 Bucaramanga, Santander (Colombia). Correo electrónico: [email protected] Callawayasaurus
    [Show full text]
  • Cryptoclidid Plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert
    Journal of Vertebrate Paleontology ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/ujvp20 Cryptoclidid plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert Rodrigo A. Otero , Jhonatan Alarcón-Muñoz , Sergio Soto-Acuña , Jennyfer Rojas , Osvaldo Rojas & Héctor Ortíz To cite this article: Rodrigo A. Otero , Jhonatan Alarcón-Muñoz , Sergio Soto-Acuña , Jennyfer Rojas , Osvaldo Rojas & Héctor Ortíz (2020): Cryptoclidid plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert, Journal of Vertebrate Paleontology, DOI: 10.1080/02724634.2020.1764573 To link to this article: https://doi.org/10.1080/02724634.2020.1764573 View supplementary material Published online: 17 Jul 2020. Submit your article to this journal Article views: 153 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=ujvp20 Journal of Vertebrate Paleontology e1764573 (14 pages) © by the Society of Vertebrate Paleontology DOI: 10.1080/02724634.2020.1764573 ARTICLE CRYPTOCLIDID PLESIOSAURS (SAUROPTERYGIA, PLESIOSAURIA) FROM THE UPPER JURASSIC OF THE ATACAMA DESERT RODRIGO A. OTERO,*,1,2,3 JHONATAN ALARCÓN-MUÑOZ,1 SERGIO SOTO-ACUÑA,1 JENNYFER ROJAS,3 OSVALDO ROJAS,3 and HÉCTOR ORTÍZ4 1Red Paleontológica Universidad de Chile, Laboratorio de Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile, [email protected]; 2Consultora Paleosuchus Ltda., Huelén 165, Oficina C, Providencia, Santiago, Chile; 3Museo de Historia Natural y Cultural del Desierto de Atacama. Interior Parque El Loa s/n, Calama, Región de Antofagasta, Chile; 4Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario, Concepción, Región del Bío Bío, Chile ABSTRACT—This study presents the first plesiosaurs recovered from the Jurassic of the Atacama Desert that are informative at the genus level.
    [Show full text]
  • Estimating the Evolutionary Rates in Mosasauroids and Plesiosaurs: Discussion of Niche Occupation in Late Cretaceous Seas
    Estimating the evolutionary rates in mosasauroids and plesiosaurs: discussion of niche occupation in Late Cretaceous seas Daniel Madzia1 and Andrea Cau2 1 Department of Evolutionary Paleobiology, Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland 2 Independent, Parma, Italy ABSTRACT Observations of temporal overlap of niche occupation among Late Cretaceous marine amniotes suggest that the rise and diversification of mosasauroid squamates might have been influenced by competition with or disappearance of some plesiosaur taxa. We discuss that hypothesis through comparisons of the rates of morphological evolution of mosasauroids throughout their evolutionary history with those inferred for contemporary plesiosaur clades. We used expanded versions of two species- level phylogenetic datasets of both these groups, updated them with stratigraphic information, and analyzed using the Bayesian inference to estimate the rates of divergence for each clade. The oscillations in evolutionary rates of the mosasauroid and plesiosaur lineages that overlapped in time and space were then used as a baseline for discussion and comparisons of traits that can affect the shape of the niche structures of aquatic amniotes, such as tooth morphologies, body size, swimming abilities, metabolism, and reproduction. Only two groups of plesiosaurs are considered to be possible niche competitors of mosasauroids: the brachauchenine pliosaurids and the polycotylid leptocleidians. However, direct evidence for interactions between mosasauroids and plesiosaurs is scarce and limited only to large mosasauroids as the Submitted 31 July 2019 predators/scavengers and polycotylids as their prey. The first mosasauroids differed Accepted 18 March 2020 from contemporary plesiosaurs in certain aspects of all discussed traits and no evidence Published 13 April 2020 suggests that early representatives of Mosasauroidea diversified after competitions with Corresponding author plesiosaurs.
    [Show full text]
  • A Revision of the Classification of the Plesiosauria with a Synopsis of the Stratigraphical and Geographical Distribution Of
    LUNDS UNIVERSITETS ARSSKRIFT. N. F. Avd. 2. Bd 59. Nr l. KUNGL. FYSIOGRAFISKA SÅLLSKAPETS HANDLINGAR, N. F. Bd 74. Nr 1. A REVISION OF THE CLASSIFICATION OF THE PLESIOSAURIA WITH A SYNOPSIS OF THE STRATIGRAPHICAL AND GEOGRAPHICAL DISTRIBUTION OF THE GROUP BY PER OVE PERSSON LUND C. W. K. GLEER UP Read before the Royal Physiographic Society, February 13, 1963. LUND HÅKAN OHLSSONS BOKTRYCKERI l 9 6 3 l. Introduction The sub-order Plesiosauria is one of the best known of the Mesozoic Reptile groups, but, as emphasized by KuHN (1961, p. 75) and other authors, its classification is still not satisfactory, and needs a thorough revision. The present paper is an attempt at such a revision, and includes also a tabular synopsis of the stratigraphical and geo­ graphical distribution of the group. Some of the species are discussed in the text (pp. 17-22). The synopsis is completed with seven maps (figs. 2-8, pp. 10-16), a selective synonym list (pp. 41-42), and a list of rejected species (pp. 42-43). Some forms which have been erroneously referred to the Plesiosauria are also briefly mentioned ("Non-Plesiosaurians", p. 43). - The numerals in braekets after the generic and specific names in the text refer to the tabular synopsis, in which the different forms are numbered in successional order. The author has exaroined all material available from Sweden, Australia and Spitzbergen (PERSSON 1954, 1959, 1960, 1962, 1962a); the major part of the material from the British Isles, France, Belgium and Luxembourg; some of the German spec­ imens; certain specimens from New Zealand, now in the British Museum (see LYDEK­ KER 1889, pp.
    [Show full text]
  • Vertebrate Remains Are Relatively Well Known in Late Jurassic Deposits of Western Cuba. the Fossil Specimens That Have Been Coll
    Paleontología Mexicana, 3 (65): 24-39 (versión impresa), 4: 24-39 (versión electrónica) Catalogue of late jurassiC VerteBrate (pisCes, reptilian) speCiMens froM western CuBa Manuel Iturralde-Vinent ¹, *, Yasmani Ceballos Izquierdo ² A BSTRACT Vertebrate remains are relatively well known in Late Jurassic deposits of western Cuba. The fossil specimens that have been collected so far are dispersed in museum collections around the world and some have been lost throughout the years. A reas- sessment of the fossil material stored in some of these museums’ collections has generated new data about the fossil-bearing lo- calities and greatly increased the number of formally identified specimens. The identified bone elements and taxa suggest a high vertebrate diversity dominated by actinopterygians and reptiles, including: long-necked plesiosaurs, pliosaurs, metriorhynchid crocodilians, pleurodiran turtles, ichthyosaurs, pterosaurs, and sauropod dinosaurs. This assemblage is commonly associated with unidentified remains of terrestrial plants and rare microor- ganisms, as well as numerous marine invertebrates such as am- monites, belemnites, pelecypods, brachiopods, and ostracods. This fossil assemblage is particularly valuable because it includes the most complete marine reptile record of a chronostratigraphic interval, which is poor in vertebrate remains elsewhere. In this contribution, the current status of the available vertebrate fossil specimens from the Late Jurassic of western Cuba is provided, along with a brief description of the fossil materials. Key words: Late Jurassic, Oxfordian, dinosaur, marine reptiles, fish, western Cuba. I NTRODUCTION Since the early 20th century, different groups of collectors have discovered 1 Retired curator, Museo a relatively rich and diverse vertebrate assemblage in the Late Jurassic stra- Nacional de Historia Natural, ta of western Cuba, which has been only partially investigated (Brown and Havana, Cuba.
    [Show full text]
  • The Importance of Winterswijk for Under- Standing Placodontiform Evolution U Vindt Een Samenvatting Aan Het Eind Van De Tekst
    Zurich Open Repository and Archive University of Zurich Main Library Strickhofstrasse 39 CH-8057 Zurich www.zora.uzh.ch Year: 2019 The importance of Winterswijk for understanding placodontiform evolution Neenan, James M ; During, Melanie A D ; Scheyer, Torsten M Abstract: Placodontiformes are basal, semi-aquatic sauropterygians that mostly preyed upon hard-shelled organisms and often had substantial dermal armour. While their fossil remains are rare, they can be found in Triassic sediments throughout Europe, the Middle East and southern China, often in the form of their unusually large, tablet-shaped teeth. Winterswijk, however, boasts one of the most important fossil records for placodontiforms in the world, with two unique genera that are not currently known from anywhere else: Palatodonta bleekeri and Pararcus diepenbroeki. Other than these, more widespread genera are probably also represented in the form of Placodus sp. and Cyamodus sp. Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-181650 Journal Article Published Version Originally published at: Neenan, James M; During, Melanie A D; Scheyer, Torsten M (2019). The importance of Winterswijk for understanding placodontiform evolution. Staringia, 73(5/6):222-225. A B C FIGURE 1. | Placodontiform morphotypes that have been found in Winterswijk. Palatodonta bleekeri (A) is the closest relative of the placodonts, and had small sharp teeth for eating soft prey. The placodonts Placodus gigas (B) and Cyamodus hildegardis (C) had large crushing teeth for eating hard-shelled prey. Note the heavy armour in Cyamodus. Reconstructions by Jaime Chirinos. The importance of Winterswijk for under- standing placodontiform evolution U vindt een samenvatting aan het eind van de tekst.
    [Show full text]
  • Mesozoic Marine Reptile Palaeobiogeography in Response to Drifting Plates
    ÔØ ÅÒÙ×Ö ÔØ Mesozoic marine reptile palaeobiogeography in response to drifting plates N. Bardet, J. Falconnet, V. Fischer, A. Houssaye, S. Jouve, X. Pereda Suberbiola, A. P´erez-Garc´ıa, J.-C. Rage, P. Vincent PII: S1342-937X(14)00183-X DOI: doi: 10.1016/j.gr.2014.05.005 Reference: GR 1267 To appear in: Gondwana Research Received date: 19 November 2013 Revised date: 6 May 2014 Accepted date: 14 May 2014 Please cite this article as: Bardet, N., Falconnet, J., Fischer, V., Houssaye, A., Jouve, S., Pereda Suberbiola, X., P´erez-Garc´ıa, A., Rage, J.-C., Vincent, P., Mesozoic marine reptile palaeobiogeography in response to drifting plates, Gondwana Research (2014), doi: 10.1016/j.gr.2014.05.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Mesozoic marine reptile palaeobiogeography in response to drifting plates To Alfred Wegener (1880-1930) Bardet N.a*, Falconnet J. a, Fischer V.b, Houssaye A.c, Jouve S.d, Pereda Suberbiola X.e, Pérez-García A.f, Rage J.-C.a and Vincent P.a,g a Sorbonne Universités CR2P, CNRS-MNHN-UPMC, Département Histoire de la Terre, Muséum National d’Histoire Naturelle, CP 38, 57 rue Cuvier,
    [Show full text]
  • How Plesiosaurs Swam: New Insights Into Their Underwater Flight Using “Ava”, a Virtual Pliosaur
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 9 October 2019 doi:10.20944/preprints201910.0094.v1 How Plesiosaurs Swam: New Insights into Their Underwater Flight Using “Ava”, a Virtual Pliosaur Max Hawthorne1,*, Mark A. S. McMenamin 2, Paul de la Salle3 1Far From The Tree Press, LLC, 4657 York Rd., #952, Buckingham, PA, 18912, United States 2Department of Geology and Geography, Mount Holyoke College, South Hadley, Massachusetts, United States 3Swindon, England *Correspondence: [email protected]; Tel.: 267-337-7545 Abstract Analysis of plesiosaur swim dynamics by means Further study attempted to justify the use of all four flippers of a digital 3D armature (wireframe “skeleton”) of a simultaneously via the use of paddle-generated vortices, pliosauromorph (“Ava”) demonstrates that: 1, plesiosaurs which require specific timing to achieve optimal additional used all four flippers for primary propulsion; 2, plesiosaurs thrust. These attempts have largely relied on anatomical utilized all four flippers simultaneously; 3, respective pairs studies of strata-compressed plesiosaur skeletons, and/or of flippers of Plesiosauridae, front and rear, traveled through preconceived notions as pertains to the paddles’ inherent distinctive, separate planes of motion, and; 4, the ability to ranges of motion [8, 10-12]. What has not been considered utilize all four paddles simultaneously allowed these largely are the opposing angles of the pectoral and pelvic girdles, predatory marine reptiles to achieve a significant increase in which strongly indicate varied-yet-complementing relations acceleration and speed, which, in turn, contributed to their between the front and rear sets of paddles, both in repose and sustained dominance during the Mesozoic.
    [Show full text]
  • Fossil Middle Triassic “Sea Cows” – Placodont Reptiles As Macroalgae Feeders Along the North-Western Tethys Coastline with Pangaea and in the Germanic Basin
    Vol.3, No.1, 9-27 (2011) Natural Science http://dx.doi.org/10.4236/ns.2011.31002 Fossil middle triassic “sea cows” – placodont reptiles as macroalgae feeders along the north-western Tethys coastline with Pangaea and in the Germanic basin Cajus G. Diedrich Paleologic, Nansenstr, Germany; [email protected] Received 19 October 2010; revised 22 November 2010; accepted 27 November 2010. ABSTRACT this plant-feeding adaptation and may even ex- plain the origin or at least close relationship of The descriptions of fossil Triassic marine pla- the earliest Upper Triassic turtles as toothless codonts as durophagous reptiles are revised algae and jellyfish feeders, in terms of the through comparisons with the sirenia and basal long-term convergent development with the si- proboscidean mammal and palaeoenvironment rens. analyses. The jaws of placodonts are conver- gent with those of Halitherium/Dugong or Mo- Keywords: Placodont Reptiles; Triassic; eritherium in their general function. Whereas Convergent Evolutionary Ecological Adaptation; Halitherium possessed a horny oral pad and Sirenia; Macroalgae Feeders; NW Tethys Shelf; counterpart and a special rasp-like tongue to Palaeoecology grind seagrass, as does the modern Dugong, placodonts had large teeth that covered their 1. INTRODUCTION jaws to form a similar grinding pad. The sirenia also lost their anterior teeth during many Mil- The extinct reptile group of the placodonts found in lions of years and built a horny pad instead and Germany and other European sites (Figure 1), a group specialized tongue to fed mainly on seagrass, of diverse marine diving reptiles, had large teeth cover- whereas placodonts had only macroalgae availa- ing the lower and complete upper jaws (Figsure 2-5) ble.
    [Show full text]
  • Morphologic and Ontogenetic Patterns in Elasmosaur Neck Length, with Comments on the Taxonomic Utility of Neck Length Variables F
    Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 6-2006 Morphologic and Ontogenetic Patterns in Elasmosaur Neck Length, with Comments on the Taxonomic Utility of Neck Length Variables F. Robin O’Keefe Marshall University, [email protected] Norton Hiller Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Aquaculture and Fisheries Commons, and the Ecology and Evolutionary Biology Commons Recommended Citation O’Keefe FR, Hiller N (2006) Morphologic and ontogenetic patterns in elasmosaur neck length, with comments on the taxonomic utility of neck length variables. Paludicola 5:206–229. This Article is brought to you for free and open access by the Biological Sciences at Marshall Digital Scholar. It has been accepted for inclusion in Biological Sciences Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. Paludicola 5(4):206-229 June 2006 by the Rochester Institute of Vertebrate Paleontology MORPHOLOGIC AND ONTOGENETIC PATTERNS IN ELASMOSAUR NECK LENGTH, WITH COMMENTS ON THE TAXONOMIC UTILITY OF NECK LENGTH VARIABLES F. Robin O'Keefe1 and Norton Hiller2 1Department of Anatomy, NYCOM 2 rm. 321, New York College of Osteopathic Medicine Old Westbury, New York 11568, [email protected] 2Canterbury Museum, Rolleston Avenue Christchurch, 8001 New Zealand, [email protected] ABSTRACT Elasmosaur cervical vertebrae are common fossils, but their taxonomic utility is limited due to a lack of understanding concerning their shape within and among taxa. In this paper, we analyze data from complete elasmosaur necks in an attempt to quantify and understand the variation in centrum dimensions.
    [Show full text]