DOCSLIB.ORG

The Genus Teliocrinus (Crinoidea, Echinodermata): a Key Taxon Among Pentacrinid Stalked Crinoids

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Genus Teliocrinus (Crinoidea, Echinodermata): a Key Taxon Among Pentacrinid Stalked Crinoids Zoological Journal of the Linnean Society, 2009, 155, 22–39. With 10 figures The genus Teliocrinus (Crinoidea, Echinodermata): a key taxon among pentacrinid stalked crinoids MICHEL ROUX1, NADIA AMÉZIANE2* and MARC ELEAUME3 1UMR CNRS 5561 Biogéosciences, 22 rue de Bourgogne, 51350 Cormontreuil, France Downloaded from https://academic.oup.com/zoolinnean/article/155/1/22/2674285 by guest on 23 November 2020 2Département Milieux et Peuplements Aquatiques, USM 0401-UMR CNRS 5178, Muséum national d’Histoire naturelle, 55 rue Buffon, 75005 Paris, France 3Département Milieux et Peuplements Aquatiques, USM 0401-UMR CNRS 5178, Muséum national d’Histoire naturelle, 55 rue Buffon, 75005 Paris, France Received 24 March 2007; accepted for publication 25 July 2007 The main characters of the stalked crinoids of the family Pentacrinitidae attributed to the genus Teliocrinus are re-evaluated from a quantitative study of phenotype variation, new observations on arm and stalk articulations, and observation of ontogenetic trends. All of the specimens collected in the northern Indian Ocean belong to the same species, i.e. Teliocrinus springeri (Clark, 1909). However, two phenotypes living at different depths remain valid as subspecies: Teliocrinus springeri springeri (Clark, 1909) and Teliocrinus springeri liliaceus (Clark, 1909). Teliocrinus shares several ontogenetic trends with Endoxocrinus, especially in nonfunctional brachial articulations and stalk symplexies. Its assignment to the Diplocrininae is confirmed. A discussion of its affinities with pentacrinid fossil genera in which the crown is well preserved suggests that Diplocrininae could have first appeared during the Lower Cretaceous. A shortening of brachitaxes and a paedomorphic trend of stalk symplexies are the main other evolutionary traits. Nonfunctional articulations are frequently found at the paedomorphic pole of the heterochronic gradient, without clear derived characters. Classification of pentacrinids mainly based on such symplesiomorphy or paedomorphic characters must be definitively abandoned. However, in post-Palaeozoic stalked crinoids the scarcity of well-preserved fossils, the high frequency of paedomorphy, and convergent adaptive characters makes phylogenetic reconstruction only based on morphological characters very difficult and specula- tive. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155, 22–39. ADDITIONAL KEYWORDS: Echinodermata – evolution – extant – fossil – ontogeny – Pentacrinitidae – taxonomy. INTRODUCTION suggested close affinities between H. springeri, Hypalocrinus naresianus (Clark, 1908), and ‘Isocri- Among the pentacrinid stalked crinoids, the genus nus’ decorus (Wyville-Thomson, 1864). Three years Teliocrinus is remarkable in having primibrachials later, Clark (1912) proposed the genus Comastrocri- united by syzygies, and secundibrachials united by nus to accommodate for H. springeri, Hypalocrinus transverse ligamentary synarthries, synostoses (or ornatus Clark, 1909a, and Hypalocrinus liliaceus syzygies), or muscular synarthries (Roux, Messing Clark, 1909b. Clark (1912) emphasized the similari- & Améziane, 2002). Teliocrinus is the only extant ties in arm divisions between Comastrocrinus genus restricted to the northern Indian Ocean. The species and comatulid species in the subfamily type species, i.e. Hypalocrinus springeri (Clark, Capillasterinae as being ‘the result of the develop- 1909), was described by Clark (1909a). Using trans- ment under the same conditions’, i.e. adaptive char- verse ligamentary synarthries in proximal brachial acters. Döderlein (1912) attributed a number of articulations as a shared character, Clark (1909a) pentacrinid specimens to a new species and new genus Teliocrinus asper. Clark (1923), considering *Corresponding author. E-mail: [email protected] T. asper as a synonym of Comastrocrinus 22 © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155, 22–39 TELIOCRINUS (ECHINODERMATA): A KEY TAXON 23 springeri, transferred species in the genus Comas- (1909a, b) and deposited in the Indian Museum in trocrinus to Teliocrinus. Clark (1928) described Calcutta. We examined specimens described by Clark Teliocrinus monarthrus as a new species. Clark (1932): the specimens dredged by HMS Investigator (1946) synonymized T. monarthrus and Teliocrinus [deposited in the National Museum of Natural springeri. Clark (1932: 390–391) synonymized Telioc- History (USNM), Smithsonian Institution, Washing- rinus ornatus and Teliocrinus liliaceus with T. ton DC, USA], and the specimen collected by the springeri. This view was adopted by Oji (1990) and Cable [deposited in the Natural History Museum by Roux et al. (2002). (NHM), London, UK] (Table 1). Rasmussen (1961, 1978), Sieverts-Doreck (1971), Phenotypic variation was explored using data from Oji (1985), and Simms (1988) based their penta- direct observations of specimens, and from descrip- crinid classification on plesiomorphic characters – tions and figures from the literature. SEM observa- Downloaded from https://academic.oup.com/zoolinnean/article/155/1/22/2674285 by guest on 23 November 2020 mainly arm transverse synarthries – without any tions were conducted with the Service of Electronic information on ontogeny (Améziane-Cominardi & Microscopy of the IFR-BI at the Pierre & Marie Curie Roux, 1994). With such a view, Neocrinus blakei University (UPMC). For descriptions we refer to the (Carpenter, 1882) was transferred to the fossil genus terminology summarized by Roux et al. (2002). Bra- Isocrinus (Rasmussen, 1961), Neocrinus decorus was chitaxes are series of brachials between branch transferred to the Jurassic genus Chladocrinus points, either following a radial and including the (Sieverts-Doreck, 1971), and members of the family first ossicle at which the arm branches (axillary), or Pentacrinitidae s.l. were separated into several new following an axillary and including the next. Brachi- families (Simms, 1988). The genus Teliocrinus was taxes, beginning immediately following the radials, referred to the family Cainocrinidae, and Endoxocri- are often specified as primibrachial, secundibrachial, nus was referred to the family Isselicrinidae. Roux tertibrachial etc. composed of primi-, secundi- and (1981) distinguished five subfamilies, mostly based tertibrach ossicles, respectively. So, for example, the on the study of extant taxa and using characters third secundibrachial is IIBr3, or IIBr3ax if axillary. from both proximal arm pattern and stalk symplexy: Clark (1909a, b) described two different species: (1) Metacrininae (Metacrinus and Saracrinus), (2) T. springeri and T. liliaceus. The former has serrated Diplocrininae (Diplocrinus – now a synonym of arms and the latter has smooth arms (Figs 1, 2). As Endoxocrinus –andTeliocrinus), (3) Isocrininae demonstrated by David et al. (2006) on Endoxocrinus, (Cenocrinus as a recent representative of the Isocri- the character states ‘serrated’ versus ‘smooth’ distin- nus lineage), (4) Balanocrininae (Neocrinus and guish between infraspecific taxa. Therefore, in the Hypalocrinus as recent representatives of the Bal- first phase of the study we analyse without prejudg- anocrinus lineage), and (5) Pentacrinitinae (extinct ing the taxonomic status of these two phenotypes, and since the Late Jurassic). In the views of both Roux call them ‘phenotype springeri’ and ‘phenotype lili- (1981) (see also detailed historical introduction in aceus’. David et al., 2006) and Simms (1988), the general In this study synostosis and syzygy are used as term ‘isocrinids’ became inappropriate because it defined in Roux et al. (2002). SEM observations should be restricted to one family or subfamily that (Macurda, Meyer & Roux, 1978) have clarified the includes the genus Isocrinus. In their revision of the distinction between synostosis and syzygy using the genus Endoxocrinus, David et al. (2006) clarified the different types of stereom on facet articulation in hierarchy of characters in Diplocrininae. This led to pentacrinids (Roux, 1981; Améziane-Cominardi & the distinction of different ecophenotypes as subspe- Roux, 1994; Roux et al., 2002). The facets of a synos- cies related to depth and hydrodynamics, showing tosis are mainly covered by a stereom of regular singular adaptive characters mainly in their stalk. small meshes (synostosial stereom). In crinoid arms David et al. (2006) also suggested that Teliocrinus a synostosis transforms into a syzygy when an could be the oldest living representative of the sub- irregular and thick meshwork (syzygial stereom) family Diplocrininae. predominates, and can develop a vermiculated We offer a complementary description of Teliocrinus pattern or radial crenularium. During ontogeny, based on a re-examination of the characters in all synostosis is a primary stage and syzygy is a known specimens. We examine the place of this genus derived (secondary) stage. In intermediate stages, a in pentacrinid evolution and why there are difficulties syzygial stereom and crenularium may appear on to establish monophyletic groups. facets, whereas the suture remains synostosis-like in external morphology. In pentacrinid arms this stage is classically refered to as cryptosyzygy (Moore MATERIAL AND METHODS & Teichert, 1978). As a consequence, the term cryp- Holotypes of the crinoid species dredged during the tosyzygy is inappropriate and confusing, and must Investigator cruises were briefly described by Clark be dropped. © 2009 The Linnean Society of London, Zoological Journal of the
Load more

Recommended publications
  • Early Stalked Stages in Ontogeny of the Living Isocrinid Sea Lily Metacrinus Rotundus
    Published for The Royal Swedish Academy of Sciences and The Royal Danish Academy of Sciences and Letters Acta Zoologica (Stockholm) 97: 102–116 (January 2016) doi: 10.1111/azo.12109 Early stalked stages in ontogeny of the living isocrinid sea lily Metacrinus rotundus Shonan Amemiya,1,2,3 Akihito Omori,4 Toko Tsurugaya,4 Taku Hibino,5 Masaaki Yamaguchi,6 Ritsu Kuraishi,3 Masato Kiyomoto2 and Takuya Minokawa7 Abstract 1Department of Integrated Biosciences, Amemiya,S.,Omori,A.,Tsurugaya,T.,Hibino,T.,Yamaguchi,M.,Kuraishi,R., Graduate School of Frontier Sciences, The Kiyomoto,M.andMinokawa,T.2016.Earlystalkedstagesinontogenyoftheliving University of Tokyo, Kashiwa, Chiba, isocrinid sea lily Metacrinus rotundus. — Acta Zoologica (Stockholm) 97: 102–116. 277-8526, Japan; 2Marine and Coastal Research Center, Ochanomizu University, The early stalked stages of an isocrinid sea lily, Metacrinus rotundus,wereexam- Ko-yatsu, Tateyama, Chiba, 294-0301, ined up to the early pentacrinoid stage. Larvae induced to settle on bivalve shells 3 Japan; Research and Education Center of and cultured in the laboratory developed into late cystideans. Three-dimensional Natural Sciences, Keio University, Yoko- (3D) images reconstructed from very early to middle cystideans indicated that hama, 223-8521, Japan; 4Misaki Marine 15 radial podia composed of five triplets form synchronously from the crescent- Biological Station, Graduate School of Sci- ence, The University of Tokyo, Misaki, shaped hydrocoel. The orientation of the hydrocoel indicated that the settled Kanagawa, 238-0225, Japan; 5Faculty of postlarvae lean posteriorly. In very early cystideans, the orals, radials, basals and Education, Saitama University, 255 Shim- infrabasals, with five plates each in the crown, about five columnals in the stalk, o-Okubo, Sakura-ku, Saitama City, 338- and five terminal stem plates in the attachment disc, had already formed.
    [Show full text]
  • Echinodermata) and Their Permian-Triassic Origin
    Molecular Phylogenetics and Evolution 66 (2013) 161-181 Contents lists available at SciVerse ScienceDirect FHYLÖGENETICS a. EVOLUTION Molecular Phylogenetics and Evolution ELSEVIER journal homepage:www.elsevier.com/locate/ympev Fixed, free, and fixed: The fickle phylogeny of extant Crinoidea (Echinodermata) and their Permian-Triassic origin Greg W. Rouse3*, Lars S. Jermiinb,c, Nerida G. Wilson d, Igor Eeckhaut0, Deborah Lanterbecq0, Tatsuo 0 jif, Craig M. Youngg, Teena Browning11, Paula Cisternas1, Lauren E. Helgen-1, Michelle Stuckeyb, Charles G. Messing k aScripps Institution of Oceanography, UCSD, 9500 Gilman Drive, La Jolla, CA 92093, USA b CSIRO Ecosystem Sciences, GPO Box 1700, Canberra, ACT 2601, Australia c School of Biological Sciences, The University of Sydney, NSW 2006, Australia dThe Australian Museum, 6 College Street, Sydney, NSW 2010, Australia e Laboratoire de Biologie des Organismes Marins et Biomimétisme, University of Mons, 6 Avenue du champ de Mars, Life Sciences Building, 7000 Mons, Belgium fNagoya University Museum, Nagoya University, Nagoya 464-8601, Japan s Oregon Institute of Marine Biology, PO Box 5389, Charleston, OR 97420, USA h Department of Climate Change, PO Box 854, Canberra, ACT 2601, Australia 1Schools of Biological and Medical Sciences, FI 3, The University of Sydney, NSW 2006, Sydney, Australia * Department of Entomology, NHB E513, MRC105, Smithsonian Institution, NMNH, P.O. Box 37012, Washington, DC 20013-7012, USA k Oceanographic Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL 33004, USA ARTICLE INFO ABSTRACT Añicle history: Although the status of Crinoidea (sea lilies and featherstars) as sister group to all other living echino- Received 6 April 2012 derms is well-established, relationships among crinoids, particularly extant forms, are debated.
    [Show full text]
  • Zoogeography of Tropical Western Atlantic Crinoidea (Echinodermata) David L
    Nova Southeastern University NSUWorks Oceanography Faculty Articles Department of Marine and Environmental Sciences 7-1-1978 Zoogeography of Tropical Western Atlantic Crinoidea (Echinodermata) David L. Meyer University of Cincinnati - Main Campus Charles G. Messing University of Miami, [email protected] Donald B. Macurda Jr. University of Michigan - Ann Arbor Find out more information about Nova Southeastern University and the Oceanographic Center. Follow this and additional works at: http://nsuworks.nova.edu/occ_facarticles Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons Recommended Citation Meyer, David L., Charles G. Messing, and Donald B. Macurda Jr. "Biological results of the University of Miami deep-sea expeditions. 129. Zoogeography of tropical western Atlantic Crinoidea (Echinodermata)." Bulletin of Marine Science 28, no. 3 (1978): 412-441. This Article is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been accepted for inclusion in Oceanography Faculty Articles by an authorized administrator of NSUWorks. For more information, please contact [email protected]. BULLETIN OF MARINE SCIENCE, 28(3): 412-441, 1978 BIOLOGICAL RESULTS OF THE UNIVERSITY OF MTAMI DEEP-SEA EXPEDITIONS. 129. ZOOGEOGRAPHY OF TROPICAL WESTERN ATLANTIC CRINOIDEA (ECHINODERMATA) David L. Meyer, Charles G. Messing, and Donald B. Macurda, Jr. ABSTRACT Recent collcctions of crinoids from the intertidal zone to ],650 m in the tropical western Atlantic have provided significant range extensions for more than half of the 44 comatulid and stalked species known from the region. Of the 34 comatulid species, over 60% are endemic to the region; of the 10 stalked species, 90% are endemic.
    [Show full text]
  • Isocrinid Crinoids from the Late Cenozoic of Jamaica
    A tlantic G eology 195 Isocrinid crinoids from the late Cenozoic of Jamaica Stephen K. Donovan Department of Geology, University of the West Indies, Mona, Kingston 7, Jamaica Date Received April 8, 1994 Date A ccepted A ugust 26, 1994 Eight species of isocrinines have been documented from the Lower Cretaceous to Pleistocene of Jamaica. New finds include a second specimen of a Miocene species from central north Jamaica, previously regarded as Diplocrinus sp. but reclassified as Teliocrinus? sp. herein. Extant Teliocrinus is limited to the Indian Ocean, although Miocene specimens have been recorded from Japan, indicating a wider distribution during the Neogene. One locality in the early Pleistocene Manchioneal Formation of eastern Jamaica has yielded three species of isocrinine, Cenocrirtus asterius (Linne), Diplocrinus maclearanus (Thomson) and Neocrinus decorus Thomson. These occur in association with the bourgueticrinine Democrinus sp. or Monachocrinus sp. These taxa are all extant and suggest a minimum depositional depth for the Manchioneal Formation at this locality of about 180 m. This early Pleistocene fauna represents the most diverse assemblage of fossil crinoids docu­ mented from the Antillean region. Huit especes d’isocrinines de la periode du Cretace inferieur au Pleistocene de la Jamai'que ont ete documentees. Les nouvelles decouvertes comprennent un deuxieme specimen d’une espece du Miocene du nord central de la Jamai'que, auparavant consideree comme l’espece Diplocrinus, mais reclassifiee en tant que Teliocrinus? aux presentes. Le Teliocrinus existant est limite a l’ocean Indien, meme si on a releve des specimens du Miocene au Japon, ce qui est revelateur d’une distribution plus repandue au cours du Neogene.
    [Show full text]
  • Predation, Resistance, and Escalation in Sessile Crinoids
    Predation, resistance, and escalation in sessile crinoids by Valerie J. Syverson A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Geology) in the University of Michigan 2014 Doctoral Committee: Professor Tomasz K. Baumiller, Chair Professor Daniel C. Fisher Research Scientist Janice L. Pappas Professor Emeritus Gerald R. Smith Research Scientist Miriam L. Zelditch © Valerie J. Syverson, 2014 Dedication To Mark. “We shall swim out to that brooding reef in the sea and dive down through black abysses to Cyclopean and many-columned Y'ha-nthlei, and in that lair of the Deep Ones we shall dwell amidst wonder and glory for ever.” ii Acknowledgments I wish to thank my advisor and committee chair, Tom Baumiller, for his guidance in helping me to complete this work and develop a mature scientific perspective and for giving me the academic freedom to explore several fruitless ideas along the way. Many thanks are also due to my past and present labmates Alex Janevski and Kris Purens for their friendship, moral support, frequent and productive arguments, and shared efforts to understand the world. And to Meg Veitch, here’s hoping we have a chance to work together hereafter. My committee members Miriam Zelditch, Janice Pappas, Jerry Smith, and Dan Fisher have provided much useful feedback on how to improve both the research herein and my writing about it. Daniel Miller has been both a great supervisor and mentor and an inspiration to good scholarship. And to the other paleontology grad students and the rest of the department faculty, thank you for many interesting discussions and much enjoyable socializing over the last five years.
    [Show full text]
  • Echinoderm Research and Diversity in Latin America
    Echinoderm Research and Diversity in Latin America Bearbeitet von Juan José Alvarado, Francisco Alonso Solis-Marin 1. Auflage 2012. Buch. XVII, 658 S. Hardcover ISBN 978 3 642 20050 2 Format (B x L): 15,5 x 23,5 cm Gewicht: 1239 g Weitere Fachgebiete > Chemie, Biowissenschaften, Agrarwissenschaften > Biowissenschaften allgemein > Ökologie Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. Chapter 2 The Echinoderms of Mexico: Biodiversity, Distribution and Current State of Knowledge Francisco A. Solís-Marín, Magali B. I. Honey-Escandón, M. D. Herrero-Perezrul, Francisco Benitez-Villalobos, Julia P. Díaz-Martínez, Blanca E. Buitrón-Sánchez, Julio S. Palleiro-Nayar and Alicia Durán-González F. A. Solís-Marín (&) Á M. B. I. Honey-Escandón Á A. Durán-González Laboratorio de Sistemática y Ecología de Equinodermos, Instituto de Ciencias del Mar y Limnología (ICML), Colección Nacional de Equinodermos ‘‘Ma. E. Caso Muñoz’’, Universidad Nacional Autónoma de México (UNAM), Apdo. Post. 70-305, 04510, México, D.F., México e-mail: [email protected] A. Durán-González e-mail: [email protected] M. B. I. Honey-Escandón Posgrado en Ciencias del Mar y Limnología, Instituto de Ciencias del Mar y Limnología (ICML), UNAM, Apdo. Post. 70-305, 04510, México, D.F., México e-mail: [email protected] M. D. Herrero-Perezrul Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, Ave.
    [Show full text]
  • Experimental Neoichnology of Crawling Stalked Crinoids
    Swiss Journal of Palaeontology https://doi.org/10.1007/s13358-018-0158-9 (0123456789().,-volV)(0123456789().,-volV) REGULAR RESEARCH ARTICLE Experimental neoichnology of crawling stalked crinoids 1,2 3 4 1,2 5 Krzysztof R. Brom • Kazumasa Oguri • Tatsuo Oji • Mariusz A. Salamon • Przemysław Gorzelak Received: 13 June 2018 / Accepted: 5 July 2018 Ó The Author(s) 2018 Abstract Stalked crinoids have long been considered sessile. In the 1980s, however, observations both in the field and of laboratory experiments proved that some of them (isocrinids) can actively relocate by crawling with their arms on the substrate, and dragging the stalk behind them. Although it has been argued that this activity may leave traces on the sediment surface, no photographs or images of the traces produced by crawling crinoids have been available. Herein, we present results of neoichnological experiments using the shallowest species of living stalked crinoid, Metacrinus rotundus, dredged from Suruga Bay (near the town of Numazu, Shizuoka Prefecture, * 140 m depth). Our results demonstrate that isocrinids produce characteristic locomotion traces, which have some preservation potential. They are composed of rather deep and wide, sometimes weakly sinuous, central drag marks left by the stalk and cirri, and short, shallow scratch marks made by the arms. Based on the functional morphology and taphonomy, it has been argued that the ability to autotomize the stalk and relocate had already evolved in the oldest stem-group isocrinids (holocrinids), likely in response to increased benthic predation pressure during the so-called Mesozoic marine revolution. Our data show that this hypothesis may be corrob- orated in the future by ichnological findings, which may provide more direct proof of active locomotion in Triassic holocrinids.
    [Show full text]
  • The Effect of Sublethal Predation on the Biology of Echinoderms
    OCEANOLOGICA ACTA- VOL. 19- W 3-4 ~ -----~- Dis turban ce The effect of sublethal predation Predation Sublethal predation on the biology of echinoderms Echinoderms Perturbation Prédation Prédation sublétale Echinoderme John M. LA WREN CE a and Julio VASQUEZ b a Department of Biology, University of South Florida, Tampa, FL 33620, U.S.A. b Departamento de Biologia Marina, Universidad Cat6lica del Norte, Coquimbo, Chile. Received 17/01/95, in revised form 08/01196, accepted 11101196. ABSTRACT In contrast to plants, predation on animais is usually lethal. Analysis of the effect of predation on animal populations and on predator-prey dynamics typically assumes this is the case. However, sublethal predation occurs in echinoderms, primarily on the arms of crinoids, asteroids, and ophiuroids. Sublethal predation is important in the se echinoderms as it meets one of Harris' ( 1989) major crite­ ria, affecting basic biological processes such as acquisition of food and allocation of nutrients to growth and reproduction. Sublethal predation would have an effect on their ecological role. It is essential to consider sublethal predation in the analysis of the life-histories of these species. RÉSUMÉ Les effets de la prédation sublétale sur la biologie des échino­ dermes. A l'inverse de la plante, l'animal subit une prédation qui lui est habituellement mortelle. Ceci est confirmé par la plupart des analyses de prédation au sein des populations animales et de la dynamique prédateur/proie. Cependant une préda­ tion sublétale c'est-à-dire sans effet fatal, existe chez les échinodermes, principa­ lement chez les crinoïdes, astéries et ophiures. Pour répondre à cette définition, ce genre de prédation doit répondre au critère de Harris ( 1989) c'est-à-dire influencer les processus de base tels que la croissance et la reproduction et varier en fonction de la densité de la population en cause.
    [Show full text]
  • The Pelagic Propagule's Toolkit
    The pelagic propagule’s toolkit: An exploration of the morphology, swimming capacity and behaviour of marine invertebrate propagules by © Emaline M. Montgomery A Dissertation submitted to the School of Graduate Studies in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Marine Biology, Department of Ocean Sciences, Faculty of Science, Memorial University of Newfoundland June 2017 St. John’s, Newfoundland and Labrador Abstract The pelagic propagules of benthic marine animals often exhibit behavioural responses to biotic and abiotic cues. These behaviours have implications for understanding the ecological trade-offs among complex developmental strategies in the marine environment, and have practical implications for population management and aquaculture. But the lack of life stage-specific data leaves critical questions unanswered, including: (1) Why are pelagic propagules so diverse in size, colour, and development mode; and (2) do certain combinations of traits yield propagules that are better adapted to survive in the plankton and under certain environments? My PhD research explores these questions by examining the variation in echinoderm propagule morphology, locomotion and behaviour during ontogeny, and in response to abiotic cues. Firstly, I examined how egg colour patterns of lecithotrophic echinoderms correlated with behavioural, morphological, geographic and phylogenetic variables. Overall, I found that eggs that developed externally (pelagic and externally-brooded eggs) had bright colours, compared
    [Show full text]
  • Compositional and Taphonomic Variations in Modern Crinoid-Rich Sediments from the Deep- Water Margin of a Carbonate Bank Ghislaine Llewellyn Harvard University
    Nova Southeastern University NSUWorks Marine & Environmental Sciences Faculty Articles Department of Marine and Environmental Sciences 12-1-1993 Compositional and Taphonomic Variations in Modern Crinoid-Rich Sediments from the Deep- Water Margin of a Carbonate Bank Ghislaine Llewellyn Harvard University Charles G. Messing Nova Southeastern University, [email protected] Find out more information about Nova Southeastern University and the Halmos College of Natural Sciences and Oceanography. Follow this and additional works at: https://nsuworks.nova.edu/occ_facarticles Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons Recommended Citation Llewellyn, Ghislaine, and Charles G. Messing. "Compositional and taphonomic variations in modern crinoid-rich sediments from the deep-water margin of a carbonate bank." Palaios (1993): 554-573. This Article is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been accepted for inclusion in Marine & Environmental Sciences Faculty Articles by an authorized administrator of NSUWorks. For more information, please contact [email protected]. 554 RESEARCH REPORTS Compositionaland TaphonomicVariations in Modern Crinoid-RichSediments from the Deep-Water Marginof a CarbonateBank GHISLAINE LLEWELLYN Departmentof Earth and Planetary Sciences,Harvard University,Cambridge, MA 02138 CHARLES G. MESSING Nova OceanographicCenter, 8000 North Ocean Drive,Dania, FL 33004 PALAIOS, 1993, V. 8, p. 554-573 be identifiedin deep-watercarbonate bank-margin sed- iments.Such changesare largelya responseto differences Multivariateanalyses ofthe coarse-grainedfraction (>2 in benthicflow regime associated withsmall-scale topo- mm) of sedimentsaccumulating in deep water (419-434 graphicirregularities and may providean importantdi- m) along the westernmargin of the Little Bahama Bank agnostictool for the interpretationof fossil assemblages.
    [Show full text]
  • The Isocrinine Crinoid Isselicrinus Rovereto from the Paleogene of the Americas
    Swiss Journal of Palaeontology (2019) 138:317–324 https://doi.org/10.1007/s13358-019-00195-3 (0123456789().,-volV)(0123456789().,- volV) REGULAR RESEARCH ARTICLE The isocrinine crinoid Isselicrinus Rovereto from the Paleogene of the Americas 1 2 3 4 Stephen K. Donovan • Sven N. Nielsen • J. Velez-Juarbe • Roger W. Portell Received: 8 May 2019 / Accepted: 30 May 2019 / Published online: 15 June 2019 Ó Akademie der Naturwissenschaften Schweiz (SCNAT) 2019 Abstract Crinoids are uncommon fossils in the Cenozoic. This scarcity means that even disarticulated elements are of note. Two species of the isocrinine Isselicrinus Rovereto are described from their disarticulated columns. Isselicrinus sp. A is from the upper Eocene Moritzian Stage of Tierra del Fuego. These crinoids have a robust column, varying from pentalobate (proximal?) to rounded pentagonal (distal?) in section and with consistently depressed areola petals. Isselicrinus sp. B is from the Lower Oligocene Juana Diaz Formation of Puerto Rico. This species is typified by slender pluricolumnals, always rounded pentagonal in section, and long noditaxes. Proximal and distal pluricolumnal morphologies are not distinguishable. Keywords Tierra del Fuego Á Puerto Rico Á Oligocene Á Systematics Á Taphonomy Introduction water deposits from this interval were the comatulids, whose fossil record remains patchy because of their low ‘‘As a result of the distribution of sea and land during preservation potential and the small size of their compo- the Tertiary, which was similar to that of today, most nent parts. The tiny ossicles of comatulids rarely occur in marine sediments were deposited in shallow water concentrations, so it takes a keen eye to spot them.
    [Show full text]
  • Paleontological Contributions
    THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS February 10, 1975 Paper 74 THE MICROSTRUCTURE OF THE CRINOID ENDOSKELETON' DONALD B. MACURDA, JR. AND DAVID L. MEYER The University of Michigan, Ann Arbor; Smithsonian Tropical Research Institute, Balboa, Panama ABSTRACT The microstructure of the crinoid endoskeleton is highly differentiated in Recent crinoids, reflecting types of tissue, the functions of the plates, and the autecology of the animals. Stem plates are interconnected by long ligament fibers that penetrate into the skeleton, producing a galleried structure. Both movable and immovable articulations exist; specialized projections stabilize the plates along a fulcral ridge in some synarthries. The cirri, attached to a nodal stem plate or a centrodorsal, have differentiated articular surfaces in which the greater development of ligaments in a dorsal (lower) position enhances their clasping power. Accessory nerve canals are present in some stem plates and penetrate the basais into the region of the axial organ. The basais and radials are pierced by intricate nerve canals that give rise to branches enclosed within the brachials. Several types of articulations are found within the arms. The muscular articulation, divided into three parts, has galleried microstructure in two of these for the long ligament fibers that penetrate the skeleton, whereas muscle tissue does not and is reflected in a more disordered or labyrinthic microstructure. Many fulcral ridges show wear. Other arm articulations such as syzygies, synarthries, and symplexies have highly differentiated, three-dimensional surfaces. A pinnule articulates with the brachial on an asymmetrical muscular articulation. By having subsequent pinnular articulations articulate in a differ- ent plane and also modifying the fulcral ridges, great flexibility can be achieved in some pinnules.
    [Show full text]