DOCSLIB.ORG

Parts of Insects the Integument Cuticle Exoskeleton

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Parts of Insects the Integument Cuticle Exoskeleton The Integument Week #2 Consequences of having your skeleton on the outside External Morphology 1. Muscles attach on the inside of Insects 2. The exoskeleton is also a suit of armor 3. Sensing the outside world is a challenge 4. Growth is impaired 5. There is a limit on insect size Parts of insects • Integument (body wall) • Thorax – Skeleton – Segments – Cuticle – Legs – Formation – Wings – Physical properties – Modifications • Head • Abdomen – Major functions – Cerci – Eyes – Ovipositor – Mouthparts: types and – Modifications positions – Antennae – Modifications The Integument Outer covering; includes cuticle and epidermis Cuticle The external skeletal structure, composed of chitin and protein Exoskeleton The external, hardened, cuticular skeleton to which muscles are attached internally 1 The Integument Consequences of having your skeleton on the outside 1. Muscles attach on the inside 2. The exoskeleton is also a suit of armor 3. Sensing the outside world is a challenge 4. Growth is impaired 5. There is a limit on insect size 2 The Integument Consequences of having your skeleton on the outside 1. Muscles attach on the inside 2. The exoskeleton is also a suit of armor 3. Sensing the outside world is a challenge 4. Growth is impaired 5. There is a limit on insect size The Integument Consequences of having your skeleton on the outside 1. Muscles attach on the inside 2. The exoskeleton is also a suit of armor 3. Sensing the outside world is a challenge 4. Growth is impaired 5. There is a limit on insect size Chitin, polysaccaride similar to cellulose; gives the cuticle its strength Chitin, a major cuticle component, is insoluble in water, alcohol, ether, dilute acids, and dilute or concentrate alkali. http://www.youtube.com/watch?v=IWRtJYW7GAs 3 Chitin is the main component of the cell walls of fungi, the exoskeletons of arthropods, including crustaceans, and the mouthparts of mollusks and cephalopods, including squid and octopuses. Fig 2.1 in textbook Epicuticle (0.1-3.0 μm) Cross‐section Structure: of the insect Inner epicuticle, outer epicuticle, superficial layer. integument Also, cement layer (shellac-like layer), wax layer, superficial layer (glycoprotein). Function: protection, water retention, serves as communication surface, sunblock. cement layer wax layer TEM of Larval Sclerite superficial layer outer epicuticle Epicuticle Wax filament inner epicuticle Exocuticle Endocuticle Pore canal exocuticle Epidermis 4 Procuticle (10-500 μm) Procuticle (10-500 μm) Exocuticle: sclerotized Exocuticle: sclerotized endocuticle endocuticle Endocuticle: lamellar sheets Endocuticle: lamellar sheets of chitin of chitin Chitin, polysaccaride similar to cellulose; gives the cuticle its strength Chitin, a major cuticle component, is insoluble in water, alcohol, ether, dilute acids, and dilute or concentrate alkali. 5 Epidermis- a major Honey pot ant, biosynthetic tissue, Camponotus responsible for production of inflatus chitin fibrils, lipids, peptides and proteins found in cuticle (and hemolymph). Basement membrane- exocellular matrix that partitions insect tissues (connective tissue layer). Fig 2.1 in book Softer Side of the Exoskeleton Resilin: An elastic substance consisting of cross-linked protein chains, found in the cuticles of many insects ( intersegmental membranes, wing connective areas, leg joints (flea) Elastic cuticle regions contain high concentrations of resilin are not sclerotized. Cicada song: http://en.wikipedia.org/wiki/Cicada 6 Physical properties of cuticle: •COLOR •Permeability •Barrier to pathogens •External processes •Skeleton Physical properties of cuticle: COLOR 7 COLOR: Pigments…. From Insect Macroevolution Lecture Insects are arthropods phylum: Arthropoda They share many features with the annelids (phylum Annelida) and onychophorans (phylum Onychophora) Annelida Onychophora Onychophora Cuticle Color PIGMENTS Brown-black color- due to deposition of melanin Yellows to reds- carotenoids, papiliochromes, flavonoids and pterines Red, blues, and greens- tetrapyrroles 8 COLOR: Structural…. WIP diversity in small Hymenoptera. (A–C) Trichogrammatidae, three unidentified species (females, Costa Rica). Shevtsova E et al. PNAS 2011;108:668-673 ©2011 by National Academy of Sciences Physical properties of cuticle: Permeability 9 Physical properties of Thailand rainforest cuticle: block pathogens fungus with its carpenter ant victims •NW side of plant •25 cm up from surface •Ideal temp and humidity 10 Sandra B. Andersen, Sylvia Gerritsma, Kalsum M. Yusah, David Mayntz, Nigel L. Hywel Jones, Johan Billen, Jacobus J. Boomsma, and David P. Hughes, "The Life of a Dead Ant: The Expression of an Adaptive Extended Phenotype." The American Naturalist, Sept. 2009. Camponotus leonardi Physical properties of cuticle: External processes…. Mediterranean fruit fly (Ceratitis capitata) pulvillar pad with tenet setae. Pulvilli are the hairy adhesive organs at the end of fly legs. Tenet setae are the hairs (with adhesive ends) that make up the puvilli. The pulvilli allow the fly to attach to smooth surfaces. Sensillae or setae (hairs) © Dennis Kunkel. Spine Seta Acanthae Microtrichia 11 A hind leg of Leptoscelis tricolor (Hemiptera: Coreidae) Physical properties of cuticle: Skeleton Spines of beetles (Coleoptera) Insect parts: most information will be covered in lab and course notes Some highlights… 12 Thorax Myrmecomorphy –ant mimicking Family: Alydidae (Hemiptera) Antennae Mouthpart positions (head types) Contain complex of chemoreceptors, mechanoreceptors, thermoreceptors, and hygroreceptors used for : • Touch Humidity • Smell Hearing Many insects e.g. Many beetles Hypognathous Prognathous protrusive jaws projecting lower jaw Opisthognathous receding jaws e.g. Hemipterans (aphids, cicadas) Antennal Forms A. setaceous (dragonfly) Opisthognathous B. filiform (ground beetle) C. moniliform (bark beetle) D. clavate (darkling beetle) E. clavate (ladybird beetle) F. capitate (sap beetle) G. serrate (click beetle) H. pectinate (fire-colored beetle) I. plumose (mosquito) J. aristate (syrphid fly) K. stylate (snipe fly) L. flabellate (cedar beetle) M. lamellate (scarab beetle) N. geniculate (chalcid wasp) ar, arista; fl, flagellum; ped, pedicel; scp, scape; sty, style 13 Modifications of the thorax Entylia carinata (Hemiptera: Membracidae) (Orthoptera: Acrididae) Pronotum – design in shielding Ceresa basalis (Hemiptera: Membracidae) 14 Hemelytra membrane corium clavus Photo: Lyle Buss Heteropteran Hemiptera Types of Insect Legs Raptorial Cursorial (to prey) Elytra (to run) Saltatorial (leap) Prehensile Natatorial Fossorial (Swimming) (to dig) Membranous Wings Tergum Sternum 15 Modifications in the abdomen Examples of Ovipositors Formosan Termite Queen Isoptera (now Blattaria) Examples of Cerci 16.
Load more

Recommended publications
  • Nail Anatomy and Physiology for the Clinician 1
    Nail Anatomy and Physiology for the Clinician 1 The nails have several important uses, which are as they are produced and remain stored during easily appreciable when the nails are absent or growth. they lose their function. The most evident use of It is therefore important to know how the fi ngernails is to be an ornament of the hand, but healthy nail appears and how it is formed, in we must not underestimate other important func- order to detect signs of pathology and understand tions, such as the protective value of the nail plate their pathogenesis. against trauma to the underlying distal phalanx, its counterpressure effect to the pulp important for walking and for tactile sensation, the scratch- 1.1 Nail Anatomy ing function, and the importance of fi ngernails and Physiology for manipulation of small objects. The nails can also provide information about What we call “nail” is the nail plate, the fi nal part the person’s work, habits, and health status, as of the activity of 4 epithelia that proliferate and several well-known nail features are a clue to sys- differentiate in a specifi c manner, in order to form temic diseases. Abnormal nails due to biting or and protect a healthy nail plate [1 ]. The “nail onychotillomania give clues to the person’s emo- unit” (Fig. 1.1 ) is composed by: tional/psychiatric status. Nail samples are uti- • Nail matrix: responsible for nail plate production lized for forensic and toxicology analysis, as • Nail folds: responsible for protection of the several substances are deposited in the nail plate nail matrix Proximal nail fold Nail plate Fig.
    [Show full text]
  • Durham Research Online
    Durham Research Online Deposited in DRO: 23 May 2017 Version of attached le: Accepted Version Peer-review status of attached le: Peer-reviewed Citation for published item: Betts, Marissa J. and Paterson, John R. and Jago, James B. and Jacquet, Sarah M. and Skovsted, Christian B. and Topper, Timothy P. and Brock, Glenn A. (2017) 'Global correlation of the early Cambrian of South Australia : shelly fauna of the Dailyatia odyssei Zone.', Gondwana research., 46 . pp. 240-279. Further information on publisher's website: https://doi.org/10.1016/j.gr.2017.02.007 Publisher's copyright statement: c 2017 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ Additional information: Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom Tel : +44 (0)191 334 3042 | Fax : +44 (0)191 334 2971 https://dro.dur.ac.uk Accepted Manuscript Global correlation of the early Cambrian of South Australia: Shelly fauna of the Dailyatia odyssei Zone Marissa J.
    [Show full text]
  • Halwaxiids and the Early Evolution of the Lophotrochozoans. Science
    REPORTS functions technique) of a quantum-mechanical n- and p-regions are equal (rh = re), charge 6. T. Ohta, A. Bostwick, T. Seyller, K. Horn, E. Rotenberg, analysis of oscillations of dj around the mi- carriers injected into graphene from the contact Science 313, 951 (2006). A-B 7. V. V. Cheianov, V. I. Fal’ko, Phys. Rev. B 74, 041403 rage image of a bilayer island formed on the S shown in Fig. 4A would meet again in the (2006). other side of symmetric PNJ in the monolayer focus at the distance 2w from the source 8. M. Katsnelson, K. Novoselov, A. Geim, Nat. Phys. 2, 620 sheet. To compare Fig. 2D shows the calculated (contact D3 in Fig. 4A). Varying the gate volt- (2006). mirage image of a spike of electrostatic potential age over the p-region changes the ratio n2 = 9. V. G. Veselago, Sov. Phys. Usp. 10, 509 (1968). r r 10. J. B. Pendry, Phys. Rev. Lett. 85, 3966 (2000). (smooth at the scale of the lattice constant in h/ e. This enables one to transform the focus 11. J. B. Pendry, Nature 423, 22 (2003). graphene), which induces LDOS oscillations into a cusp displaced by about 2(|n| −1)w along 12. D. R. Smith, J. B. Pendry, M. Wiltshire, Science 305, 788 equal on the two sublattices. The difference be- the x axis and, thus, to shift the strong coupling (2004). 13. M. S. Dresselhaus, G. Dresselhaus, Adv. Phys. 51, tween these two images is caused by the lack of from the pair of leads SD3 to either SD1 (for backscattering off A-B symmetric scatterers r < r )orSD (for r > r ).
    [Show full text]
  • Decoding the Fossil Record of Early Lophophorates
    Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1284 Decoding the fossil record of early lophophorates Systematics and phylogeny of problematic Cambrian Lophotrochozoa AODHÁN D. BUTLER ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-554-9327-1 UPPSALA urn:nbn:se:uu:diva-261907 2015 Dissertation presented at Uppsala University to be publicly examined in Hambergsalen, Geocentrum, Villavägen 16, Uppsala, Friday, 23 October 2015 at 13:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Maggie Cusack (School of Geographical and Earth Sciences, University of Glasgow). Abstract Butler, A. D. 2015. Decoding the fossil record of early lophophorates. Systematics and phylogeny of problematic Cambrian Lophotrochozoa. (De tidigaste fossila lofoforaterna. Problematiska kambriska lofotrochozoers systematik och fylogeni). Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1284. 65 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9327-1. The evolutionary origins of animal phyla are intimately linked with the Cambrian explosion, a period of radical ecological and evolutionary innovation that begins approximately 540 Mya and continues for some 20 million years, during which most major animal groups appear. Lophotrochozoa, a major group of protostome animals that includes molluscs, annelids and brachiopods, represent a significant component of the oldest known fossil records of biomineralised animals, as disclosed by the enigmatic ‘small shelly fossil’ faunas of the early Cambrian. Determining the affinities of these scleritome taxa is highly informative for examining Cambrian evolutionary patterns, since many are supposed stem- group Lophotrochozoa. The main focus of this thesis pertained to the stem-group of the Brachiopoda, a highly diverse and important clade of suspension feeding animals in the Palaeozoic era, which are still extant but with only with a fraction of past diversity.
    [Show full text]
  • Paterimitra Pyramidalis Laurie, 1986, the First Tommotiid Discovered From
    1 Paterimitra pyramidalis Laurie, 1986, the first tommotiid discovered from 2 the early Cambrian of North China 3 4 Bing Pana, b, Glenn A. Brockc, Christian B. Skovstedd, Marissa J. Bettse, Timothy P. Topperf, 5 Guo-Xiang Lia, * 6 7 a State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and 8 Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China 9 b University of Science and Technology of China, Hefei 230026, China 10 c Department of Biological Sciences, Macquarie University, NSW 2109, Australia 11 d Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden. 12 e Palaeoscience Research Centre, School of Environmental and Rural Science, University of 13 New England, Armidale, NSW, Australia. 14 f Palaeoecosystems Group, Department of Earth Sciences, Durham University, Durham, UK. 15 * Corresponding author. 16 E-mail: [email protected] (B. Pan), [email protected] (G.A. Brock), 17 [email protected] (C.B. Skovsted), [email protected] (M.J. Betts), 18 [email protected] (T.P. Topper), [email protected] (G.X. Li) 19 20 ABSTRACT 21 The eccentrothecimorph tommotiid Paterimitra pyramidalis Laurie, 1986, was 22 previously only known from lower Cambrian rocks of the Northern Territory and South 23 Australia. Herein, we document the first occurrence of P. pyramidalis from the Xinji 24 Formation in the Shuiyu section at Ruicheng County, Shanxi Province, located at the 25 southwestern margin of the North China Platform. This represents the first report of a 1 26 tommotiid taxon from lower Cambrian strata of the North China Platform.
    [Show full text]
  • Research Article the Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora)
    Hindawi Publishing Corporation BioMed Research International Volume 2013, Article ID 407072, 18 pages http://dx.doi.org/10.1155/2013/407072 Research Article The Continuing Debate on Deep Molluscan Phylogeny: Evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora) I. Stöger,1,2 J. D. Sigwart,3 Y. Kano,4 T. Knebelsberger,5 B. A. Marshall,6 E. Schwabe,1,2 and M. Schrödl1,2 1 SNSB-Bavarian State Collection of Zoology, Munchhausenstraße¨ 21, 81247 Munich, Germany 2 Faculty of Biology, Department II, Ludwig-Maximilians-Universitat¨ Munchen,¨ Großhaderner Straße 2-4, 82152 Planegg-Martinsried, Germany 3 Queen’s University Belfast, School of Biological Sciences, Marine Laboratory, 12-13 The Strand, Portaferry BT22 1PF, UK 4 Department of Marine Ecosystems Dynamics, Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan 5 Senckenberg Research Institute, German Centre for Marine Biodiversity Research (DZMB), Sudstrand¨ 44, 26382 Wilhelmshaven, Germany 6 Museum of New Zealand Te Papa Tongarewa, P.O. Box 467, Wellington, New Zealand Correspondence should be addressed to M. Schrodl;¨ [email protected] Received 1 March 2013; Revised 8 August 2013; Accepted 23 August 2013 Academic Editor: Dietmar Quandt Copyright © 2013 I. Stoger¨ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families.
    [Show full text]
  • Developing Perspectives on Molluscan Shells, Part 1: Introduction and Molecular Biology
    CHAPTER 1 DEVELOPING PERSPECTIVES ON MOLLUSCAN SHELLS, PART 1: INTRODUCTION AND MOLECULAR BIOLOGY KEVIN M. KOCOT1, CARMEL MCDOUGALL, and BERNARD M. DEGNAN 1Present Address: Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, AL 35487, USA; E-mail: [email protected] School of Biological Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia CONTENTS Abstract ........................................................................................................2 1.1 Introduction .........................................................................................2 1.2 Insights From Genomics, Transcriptomics, and Proteomics ............13 1.3 Novelty in Molluscan Biomineralization ..........................................21 1.4 Conclusions and Open Questions .....................................................24 Keywords ...................................................................................................27 References ..................................................................................................27 2 Physiology of Molluscs Volume 1: A Collection of Selected Reviews ABSTRACT Molluscs (snails, slugs, clams, squid, chitons, etc.) are renowned for their highly complex and robust shells. Shell formation involves the controlled deposition of calcium carbonate within a framework of macromolecules that are secreted by the outer epithelium of a specialized organ called the mantle. Molluscan shells display remarkable morphological
    [Show full text]
  • •Nail Structure •Nail Growth •Nail Diseases, Disorders, and Conditions
    •Nail Structure Nail Theory •Nail Growth •Nail Diseases, Disorders, and Conditions Onychology The study of nails. Nail Structure 1. Free Edge – Extends past the skin. 2. Nail Body – Visible nail area. 3. Nail Wall – Skin on both sides of nail. 4. Lunula – Whitened half-moon 5. Eponychium – Lies at the base of the nail, live skin. 6. Mantle – Holds root and matrix. Nail Structure 7. Nail Matrix – Generates cells that make the nail. 8. Nail Root – Attached to matrix 9. Cuticle – Overlapping skin around the nail 10. Nail Bed – Skin that nail sits on 11. Nail Grooves – Tracks that nail slides on 12. Perionychium – Skin around nail 13. Hyponychium – Underneath the free edge Hyponychium Nail Body Nail Groove Nail Bed Lunula Eponychium Matrix Nail Root Free Edge Nail Bed Eponychium Matrix Nail Root Nail Growth • Keratin – Glue-like protein that hardens to make the nail. • Rate of Growth – 4 to 6 month to grow new nail – Approx. 1/8” per month • Faster in summer • Toenails grow faster Injuries • Result: shape distortions or discoloration – Nail lost due to trauma. – Nail lost through disease. Types of Nail Implements Nippers Nail Clippers Cuticle Pusher Emery Board or orangewood stick Nail Diseases, Disorders and Conditions • Onychosis – Any nail disease • Etiology – Cause of nail disease, disorder or condition. • Hand and Nail Examination – Check for problems • Six signs of infection – Pain, swelling, redness, local fever, throbbing and pus Symptoms • Coldness – Lack of circulation • Heat – Infection • Dry Texture – Lack of moisture • Redness
    [Show full text]
  • Segmented Worms (Phylum Annelida): a Celebration of Twenty Years of Progress Through Zootaxa and Call for Action on the Taxonomic Work That Remains
    Zootaxa 4979 (1): 190–211 ISSN 1175-5326 (print edition) https://www.mapress.com/j/zt/ Review ZOOTAXA Copyright © 2021 Magnolia Press ISSN 1175-5334 (online edition) https://doi.org/10.11646/zootaxa.4979.1.18 http://zoobank.org/urn:lsid:zoobank.org:pub:8CEAB39F-92C2-485C-86F3-C86A25763450 Segmented worms (Phylum Annelida): a celebration of twenty years of progress through Zootaxa and call for action on the taxonomic work that remains WAGNER F. MAGALHÃES1, PAT HUTCHINGS2,3, ALEJANDRO OCEGUERA-FIGUEROA4, PATRICK MARTIN5, RÜDIGER M. SCHMELZ6, MARK J. WETZEL7, HELENA WIKLUND8, NANCY J. MACIOLEK9, GISELE Y. KAWAUCHI10 & JASON D. WILLIAMS11 1Institute of Biology, Federal University of Bahia, Salvador, 40170-115, Bahia, Brazil. �[email protected]; https://orcid.org/0000-0002-9285-4008 2Australian Museum Research Institute, Australian Museum, Sydney, NSW. Australia. �[email protected]; https://orcid.org/0000-0001-7521-3930 3Biological Sciences, Macquarie University, North Ryde, NSW 2019, Australia. 4Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Tercer circuito s/n, Ciudad Universitaria, 04510, Mexico City, Mexico. �[email protected]; https://orcid.org/0000-0002-5514-9748 5Royal Belgian Institute of Natural Sciences, Taxonomy and Phylogeny, 29 rue Vautier, B-1000 Brussels, Belgium. �[email protected]; https://orcid.org/0000-0002-6033-8412 6IfAB Institute for Applied Soil Biology, Hamburg, Germany. �[email protected] 7Illinois Natural History Survey, Prairie Research Institute at the University of Illinois at Urbana-Champaign, Forbes Natural History Building, MC-652, 1816 S. Oak Street, Champaign, Illinois 61820 USA. �[email protected]; https://orcid.org/0000-0002-4247-0954 8Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden.
    [Show full text]
  • What's New in Nail Anatomy? the Latest Facts
    What’s New in Nail Anatomy? The Latest Facts! by Doug Schoon April 2019: The Internet is filled with confusing and competing misinformation about nail anatomy. I’ve been on a multi-year quest to determine all the facts but finding them has been very difficult. Many doctors and scientists are also confused by the various “schools of thought.” To get to the root of the issue, I’ve worked with many world-class medical experts and internationally known nail educators, in addition to reviewing dozens of scientific reports. I’d like to explain some new information in hopes of ending the confusion. It is agreed that the proximal nail fold (PNF) is the entire flap of skin covering the matrix, extending from the edge of the visible nail plate to the first joint of the finger. However, there is continuing disagreement about the eponychium. I’ve researched all sides of this debate and I hope this information will clear up confusion. Eponychium literally means “upon the nail”. This is the tissue that covers the new growth of nail plate. Why is there so much confusion about the location of the eponychium? Here’s why. Strangely, in some medical literature, another type of tissue is also identified as eponychium, which creates confusion. Of course, it is confusing with two different types of tissue having the same name. The eponychium creates the cuticle and covers the new growth of nail plate, this other tissue does not. To avoid confusion, we should only refer to the eponychium as the underside portion of the proximal nail fold that covers the new growth of nail plate and creates the cuticle.
    [Show full text]
  • Small Shelly Fossils from the Argillaceous Facies of the Lower Cambrian Forteau Formation of Western Newfoundland
    Small shelly fossils from the argillaceous facies of the Lower Cambrian Forteau Formation of western Newfoundland CHRISTIAN B. SKOVSTED and JOHN S. PEEL Skovsted, C.B. and Peel, J.S. 2007. Small shelly fossils from the argillaceous facies of the Lower Cambrian Forteau For− mation of western Newfoundland. Acta Palaeontologica Polonica 52 (4): 729–748. A diverse fauna of helcionelloid molluscs, hyoliths, and other small shelly fossils is described from limestone layers within the Forteau Formation of the Bonne Bay region in western Newfoundland. The fauna is dominated by internal moulds of various molluscs and tubular problematica, but also includes hyolith opercula, echinoderm ossicles, and other calcareous small shelly fossils preserved by phosphatisation. Originally organophosphatic shells are comparatively rare, but are represented by brachiopods, hyolithelminths, and tommotiids. The fauna is similar to other late Early Cambrian faunas from slope and outer shelf settings along the eastern margin of Laurentia and may be of middle Dyeran age. The similarity of these faunas indicates that at least by the late Early Cambrian, a distinctive and laterally continuous outer shelf fauna had evolved. The Forteau Formation also shares elements with faunas from other Early Cambrian provinces, strengthening ties between Laurentia and Australia, China, and Europe during the late Early Cambrian. Two new taxa of problematic fossil organisms are described, the conical Clavitella curvata gen. et sp. nov. and the wedge−shaped Sphenopteron boomerang gen. et sp. nov. Key words: Helcionellidae, Hyolitha, Brachiopoda, small shelly fossils, Cambrian, Laurentia, Newfoundland. Christian B. Skovsted [[email protected]], Centre for Ecostratigraphy and Palaeobiology, Macquarie University, NSW 2109, Marsfield, Sydney, Australia.
    [Show full text]
  • Insect Morphology
    PRINCIPLES OF INSECT MORPHOLOGY BY R. E. SNODGRASS United States Department of Agriculture Bureau of Entomolo(JY and Plant Quarantine FIRST EDITION SECOND IMPRESSION McGRA W-HILL BOOK COMPANY, INC. NEW YORK AND LONDON 1935 McGRAW-HILL PUBLICATIONS- IN THE ZOOLOGICAL SCaNCES A. FRANKLIN SHULL, CONSULTING EDITOR PRINCIPLES OF INSECT MORPHOLOGY COPYRIGHT, 1935, BY THE l\1CGRAW-HILIi BOOK COMPANY, INC. PRINTED IN THE UNITED STATES OF AMERICA All rights reserved. This book, or parts thereof, may not be reproduced in any form without permission oj the publishers. \ NLVS/IVRI 111111111 II 1111 1111111111111 01610 TaE MAPLE PRESS COMPANY, YORK, PA. PREFACE The principal value of fa cis is that they give us something to think about. A scientific textbook, therefore, should contain a fair amount of reliable information, though it may be a matter of choice with the author whether he leaves it to the reader to formulate his own ideas as to the meaning of the facts, or whether he attempts to guide the reader's thoughts along what seem to him to be the proper channels. The writer of the present text, being convinced that generalizations are more important than mere knowledge of facts, and being also somewhat partial to his own way of thinking about insects, has not been able to refrain entirely from presenting the facts of insect anatomy in a way to suggest relations between them that possibly exist only in his own mind. Each of the several chapters of this book, in other words, is an attempt to give a coherent morphological view of the fundamental nature and the apparent evolution of a particular group of organs or associated struc­ tures.
    [Show full text]