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Colour Patterns in Early Devonian Cephalopods from the Barrandian Area: Taphonomy and Taxonomy
Colour patterns in Early Devonian cephalopods from the Barrandian Area: Taphonomy and taxonomy VOJTĚCH TUREK Turek, V. 2009. Colour patterns in Early Devonian cephalopods from the Barrandian Area: Taphonomy and taxonomy. Acta Palaeontologica Polonica 54 (3): 491–502. DOI: 10.4202/app.2007.0064. Five cephalopod specimens from the Lower Devonian of Bohemia (Czech Republic) preserve colour patterns. They in− clude two taxonomically undeterminable orthoceratoids and three oncocerid nautiloids assigned to the genus Ptenoceras. The two fragments of orthocone cephalopods from the lowest Devonian strata (Lochkovian, Monograptus uniformis Zone) display colour patterns unusual in orthoceratoids. They have irregular undulating and zigzag strips that are pre− served on counterparts of adapertural regions of specimens flattened in shale, despite their original aragonitic shell having been completely dissolved. These are probably the result of the proteinous pigment inside the shell wall, being substituted during diagenesis by secondary minerals leaving only an altered trace of the original shell. Orthoceratoids from sediments unsuitable for preservation of this feature discussed here thus demonstrate an exceptional case of preservation of colour patterns, not only within Devonian cephalopods but also within other Devonian molluscs. Three specimens of Ptenoceras that preserve colour patterns come from younger Lower Devonian strata. Oblique spiral adaperturally bifurcating bands are preserved in P. alatum from the Pragian and zigzags in P. nudum from the Dalejan. Juvenile specimen of Ptenoceras? sp. from the Pragian exhibits highly undulating transversal bands—a pattern resembling colour markings in some Silu− rian oncocerids. Dark grey wavy lines observed on the superficially abraded adapical part of a phragmocone of nautiloid Pseudorutoceras bolli and interpreted formerly to be colour markings are here reinterpreted as secondary pigmented growth lines. -
MODE of LIFE of GRAPTOLITES Much of the Substance of This Paper
ACT A PALAEON.TOLOGICA POLONICA Vol. 23 1978 No.4 / .. NANCY HARTSHORNE KIRK MODE OF LIFE OF GRAPTOLITES Abstract. - The probable mode of life of the graptol,ites (crustoids, dendroids and graptoloids) is reconstructed from a, logical interpretation of their rhabdosomal structures. The readaptation of sessile colonial organisms to meet the requirements of a freely-moving existence in the plankton is regarded as the controlling factor in the evolution of the graptoloids. It is suggested that the gradual reduction in the size of the colony in the dicho graptids, biserial and uniserial graptoloids may have been a consequence of the undesirability of coloniality in the new environment, and that the graptoloids might have attained individuality, disappea):'ing into the plankton at t e time of their sup- posed extinction. .. Much of the substance of this paper was read to the Symposium on Coloniality at Durham (Systematics Association) in 1976 and should be published shortly. This version contains some new ideas, however, and also many digressions to discuss points of outstanding disagreement. Since the broad outline of my theme will be familiar to graptolitologists, as was not the case for the Systemahcs Association, I trust that the digres sions will be of use and interest in themselves, and, placed in parentheses, will not obscure too much my main argument. !tis generally believed that crustoids were encrusting, and the dend roids attached benthonic colonies. Their coloniality may have been an adaptation to the benthonic.habit, which could have arisen by failure of asexually budded zooids to separate from the' parent. By forming en crusting or tree-like' colonies small, zooids of comparatively simple orga nisation would have, been able to establish !hemselves upon the crowded sea floor and avoid being overtropped by competitors. -
Lab 8: Graptolites and Trace Fossils
Geos 223 Introductory Paleontology Spring 2006 Lab 8: Graptolites and Trace Fossils Name: Section: AIMS: This lab will introduce you to graptolites (Part A), and to a branch of paleontology known as ichnology (the study of trace fossils; Part B). By the end of Part A this lab you should be familiar with the basic anatomy of graptolites, and have an appreciation for how graptolites are used in the biostratigraphic zonation of the Lower Paleozoic. By the end of Part B of this lab you should be familiar with the basic ethological groups of trace fossils, and have an appreciation for how trace fossils can provide important paleoecological and paleoenvironmental information. PART A: GRAPTOLITES. Graptolites (Class Graptolithina) are an extinct group of colonial hemichordate deuterostomes, similar in morphology and life habit to the modern colonial pterobranch hemichordate Rhabdopleura. The graptolite colony consisted of many clonal zooids, each occupying a theca in the communal skeleton (the rhabdosome). The thecae formed in rows along branches of the rhabdosome called stipes. The rhabdosome was made of a non-mineralized, organic, non-chitinous protein called periderm. Graptolite colonies were either erect fan-like structures growing from the seafloor (most dendroid graptolites, ranging from the Middle Cambrian to the Late Carboniferous) or free-floating in the plankton (the commoner graptoloid graptolites, probably descended from dendroid ancestors and ranging from the Early Ordovician to the Early Devonian). Graptoloid graptolites are very important biostratigraphic zone fossils in Lower Paleozoic strata. 1 DENDROID GRAPTOLITES: A1: Dictyonema. Dendroid graptolite colonies formed fan-like structures with thecae-bearing stipes held apart by horizontal struts (dissepiments). -
Late Ludfordian and Early Pridoli Monograptids from the Polish Lowland
LATE LUDFORDIAN AND EARLY PRIDOLI MONOGRAPTIDS FROM THE POLISH LOWLAND ADAM URBANEK Urbanek, A. 1997. Late Ludfordian and early Pfidoli monograptids from the Polish Low land. In: A. Urbanek and L. Teller (eds), Silur ian Graptolite Faunas in the East European Platform: Stratigraphy and Evolution. - Palaeontologia Polonica 56, 87-23 1. Graptolites etched from the Mielnik-I wellcore (EPoland) reveal the main features of the development of monograptid faunas within the late Ludfordian-early Pi'idoli interval. Fifteen species and subspecies are described and Monog raptus (Slovinog raptus) subgen. n. as well as Neocolonograptu s gen. n. are erected. Morphology of many species has been described adequately for the first time and their systematic position corrected. Four grap tolite zones of the late Ludfordian are distinguished. The late Ludfordian fauna, which appears after the kozlowskii Event, is composed mainly of immigrants dominated by hooded monograptids. They reappear as a result of the Lazarus effect. Some of them initiated the lobate-spinose phyletic line terminating with Mon ograptus (Uncinatograptus) spineus, a highly characteristic index species. The lobate and the lobate-spinose types are accompanied by bilobate forms (Pse udomonoclimac is latilobu s). The graptolite sequence indicates that the appeara nce of the early Pfidoli fauna was preceded by a biotic crisis, namely the spineus Event. Therefore this fauna is made up of a few holdovers and some new elements which developed from Pristiograptus dubiu s stem lineage (Neocolonograptus gen. n., Istrograpt us Tsegelnjuk). This early assemblage, com posed of bilobate forms, was later enriched by hooded monograptid s, reappearing after the spineus Event. -
Early Silurian Graptolites from Southeastern Alaska and Their Correlation with Graptolitic Sequences in North America and the Arctic
Early Silurian Graptolites From Southeastern Alaska and Their Correlation With Graptolitic Sequences in North America and the Arctic GEOLOGICAL SURVEY PROFESSIONAL PAPER 653 Early Silurian Graptolites From Southeastern Alaska and Their Correlation With Graptolitic Sequences in North America and the Arctic By MICHAEL CHURKIN, JR., and CLAIRE CARTER GEOLOGICAL SURVEY PROFESSIONAL PAPER 653 Descriptions and illustrations of $9 species of Graptoloidea and correlation of the assemblages with other graptolitic successions in North America, the Soviet Arctic, and Great Britain UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1970 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HICKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director Library of Congress Catalog-card No. 78-605140 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1 (paper cover) CONTENTS Page Page Abstract-_ _________________________________________ 1 Standard graptolite zones for the Lower Silurian___-_._- 6 Introduction-______________________________________ 1 Lower Silurian graptolites in western North America-___ 6 Acknowledgments. ____ __--_-_________-____-__-______ 1 Systematic descriptions._____________________________ 13 Graptolites of the Descon Formation, southeastern Alaska__ _____________________________________ 2 Class Graptolithina.____________________________ 13 Description of the Descon Formation.________..___ 2 Order Graptoloidea_-___________---___-__-_- 13 Graywacke sandstone and banded -
Early Devonian Eurypterids with Bohemian Affinities from Catalonia (NE Spain)
Final draft post-refereeing from Batalleria, 7, 9-21, Barcelona (1997), ISSN: 0214-7831. Early Devonian eurypterids with Bohemian affinities from Catalonia (NE Spain) Ivo Chlupáč1, Enrique Ferrer2, José Magrans3, Ramón Mañé4, Javier Sanz5 1Institute of Geology and Palaeontology, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic 2 Carrer Lluís Solé Sabarís 31-B, 08850 Gavà, Spain 3 Paseig Amadeo Vives 12, 08840 Viladecans, Spain 4 Carrer Maó, 19, 4B. 08022 Barcelona, Spain 5 Facultade de Ciencias da Educación, Universidade da Coruña, Paseo de Ronda 47, 15011 A Coruña, Spain KEY WORDS - Arthropoda, Eurypterida, Pterygotidae, Lower Devonian (Lochkovian), NE Spain ABSTRACT - The sequence of early Lower Devonian (Lochkovian) strata with dominant anchimetamorphic shales of the Olorda Formation yielded numerous remains of eurypterids. These belong to the Family Pterygotidae and are represented by dominant species of Acutiramus (closely related or identical with the Bohemian species Acutiramus bohemicus and A. perneri), and rare finds of Pterygotus cf. barrandei. The eurypterids are typical components of a purely marine assemblage of the offshore, probably open shelf environment of Benthic Assemblage 4 to 5. The clearly expressed Bohemian affinity points to open migration routes along the northern Gondwana shelves between Bohemia and Catalonia during the early Devonian, particularly Lochkovian time. RESUMEN - Las pizarras de la Formación Olorda del Devónico Inferior (Lochkoviense) contienen numerosos restos de euriptéridos. Dichos fósiles pertenecen a la Familia Pterygotidae y corresponden en su mayor parte a especies de Acutiramus, mientras son más escasos los hallazgos de Pterygotus cf. barrandei. Los restos de Acutiramus son identificados como próximos o idénticos a las especies de Bohemia, Acutiramus bohemicus and A. -
Conodont Biostratigraphy of the Silurian–Devonian Boundary
21 Geologica et Palaeontologica 5. 21-31 2 Abb., 1 Tab. 11arburg, 30. 9. 1988 Conodont biostratigraphy of the Silurian-Devonian boundary stratotype at Klonk, Czechoslovakia Lennart ]EPPSSON with 2 Text-figures and 1 Table ]EPPSSON, Lennart: Conodont biostratigraphy of the Silurian-Devonian boundary stratotype at Klonk, Czechoslovakia. - Geologica et Palaeontologica 22: 21-3 1, 2 Text-Figs., 1 Tab.; Marburg/Lahn, 30. 9. 1988. Two new late Pridoli conodant zones are defined, the Ozarkodina steinhornensis eosteinhorn ensis s. str. Zone and the Ligonodina elegans detorta Zone. The former correlates with part of the Monograptus transgrediens graptolite lnterzone and the latter with a post M. transgre diens interregnum. Both conodont zones are identified in the condensed !atest Silurian strata exposed at Klonk, the type locality for the base of the Devonian System. The known range of Icriodus woschmidti starts below or possibly just above the base of the L. elegans detorta Zone casting serious doubt on its value for identifying the base of the Devonian. The well-known co nodont fauna from Untenri.iden may be late Silurian in age. Es werden zwei neue Conodonten-Zonen des s paten Pridolium neu definiert: die Zone der Ozar kodina steinhornensis eosteinhornensis s. str. und die Zone der Ligonodina elegans detorta. Die erste Zone liillt sich mit Teilen der Monograptus transgrediens-lnterzone parallelisieren, die letztere mit einem auf die M. transgrediens-Zone folgenden lnterregnum. Beide Zonen konnen in der kondensierten spiitestsilurischen Schichtfolge von Klonk, der Typlokalitiit fi.ir die Basis des Devon-Systems, erkannt werden. Die bekannte Reichweite des Icriodus woschmidti beginnt unter oder moglicherweise gerade i.iber der Basis der L. -
A Critique of Graptolite Classification, and a Revision of the Suborders Diplograptina and Monograptina
Downloaded from http://sp.lyellcollection.org/ by guest on September 29, 2021 A critique of graptolite classification, and a revision of the suborders Diplograptina and Monograptina John Rigby SUMMARY: Three broad styles of modern graptolite classifications are identified, each being based on a framework laid down in the nineteenth century. Each style is critically reviewed with regard to its potential for the expression of presently know phyletic relationships. Following the style of classification adopted by Bulman (1970), family and subfamily taxa within the suborders Diplograptina and Monograptina are revised. Over the last century there have been many virgula, a hollow rod running down the centre of attempts to produce a satisfactory classification certain biserial forms and along the dorsal edge of the graptolites. Despite the large number of the monograptid stipe. Forms without the produced, most can be assigned to one of three virgula possessed a nema, thought by Mu in 1950 styles, each based on work done before 1900 by to be a solid rod. In fact this structure is now just two authors, Lapworth in 1880 and Frech in considered to be same as the virgula, and hence 1897. Their two methods of classification differed this basic division of Frech (1897) and the widely, and it is their differences in approach 'Chinese' classification is unsound. The Axono- which today give us such extremes and lack of lipa (forms without the virgula) comprised the conformity as far as graptolite classification is equivalent forms of the 'Western' system's Didy- concerned. The three styles, developed since mograptina, whilst the Axonophora (forms with 1950, are as follows: the virgula) comprised those forms included in 1 A 'Chinese' system, as typified by the work of Bulman's (1970) suborders Glossograptina, Dip- Mu (1950, 1973), Mu & Zhan (1966), and Yu lograptina, and Monograptina. -
Morphogenetic Gradients in Graptolites and Bryozoans
Morphogenetic gradients in graptolites and bryozoans ADAM URBANEK Urbanek, A. 2004. Morphogenetic gradients in graptolites and bryozoans. Acta Palaentologica Polonica 49 (4): 485–504. Despite independent evolution of coloniality in hemichordates and bryozoans, their colonies show common features. In both instances colony is a genet or clonal system composed of zygotic oozooid and a number of blastozooids (= modules) integrated by physical continuity of tissues, sharing a common genotype and subject to common morphogenetic control. In some groups of graptolites and bryozoans, colonies display a regular morphological gradient. Simple graptoloid and bryozoan colonies consist of a proximal zone of astogenetic change and a distal zone of astogenetic repetition. Observed morphological gradient may be attributed to diffusion, along the colony axis, of a morphogen produced by the oozooid; in the zone of astogenetic change the morphogen is above certain threshold level and drops below it in the zone of asto− genetic repetition. This model is supported by observations on regeneration of fractured graptoloid colonies. Regenera− tive branch never displays astogenetic change. The same rule is valid for regeneration of fractured bryozoan colonies. While the early astogeny of simple bryozoan colonies may be explained within the framework of the gradient theory, the late astogeny of more complex ones involves multiple succession of zones of change and repetition, without analogy in astogeny of graptoloids. Thus, late astogeny in bryozoan colonies may be controlled by cyclic somatic/reproductive changes, probably independent of the primary morphogen. Evolutionary changes in the graptoloid colonies involve both the spreading of the novelties over a greater number of zooids (penetrance) and an increase in the degree of phenotypic manifestation of a given character (expressivity). -
Short Notes on Alaska Geology 2003
PROFESSIONAL REPORT 120 SHORT NOTES ON ALASKA GEOLOGY 2003 State of Alaska Department of Natural Resources DIVISION OF GEOLOGICAL & GEOPHYSICAL SURVEYS Rodney A. Combellick Acting Director 2003 SHORT NOTES ON ALASKA GEOLOGY 2003 Edited by Karen H. Clautice and Paula K. Davis Division of Geological & Geophysical Surveys Professional Report 120 Recent research on Alaska geology Fairbanks, Alaska 2003 Front cover photo: Badlands topography in poorly consolidated sandstone of the Eocene Sagavanirktok Formation at Franklin Bluffs on Alaska’s North Slope south of Prudhoe Bay. (Photo by Gil Mull) i FOREWORD In keeping with the tradition of previous issues of Short Notes on Alaska Geology, this issue offers articles on a range of geologic topics in Alaska as diverse as the authors who prepared them. By my brief read, the articles cover the fields of geochemistry, geochronology, mineralogy, petrology, petrography, structural geology, stratigraphy, sedimentology, and paleontology. The authors represent the Alaska Division of Geological & Geophysical Surveys (DGGS), University of Alaska Fairbanks, U.S. Geological Survey, and numerous other universities and private companies in the U.S., Canada, Ireland, and even Czech Republic. We greatly appreciate their efforts in this significant contribution toward STATE OF ALASKA advancing the knowledge of Alaska’s geology. Frank H. Murkowski, Governor DEPARTMENT OF NATURAL RESOURCES Assembling and publishing a high-quality collection of peer- Tom Irwin, Commissioner reviewed articles such as this require significant dedication of time and effort over a period of at least a year and a half. For this issue DIVISION OF GEOLOGICAL & of Short Notes, Karen Clautice served as technical editor and Paula GEOPHYSICAL SURVEYS Davis as publications specialist, in addition to their regular work Rodney A. -
Evolution of Retiolitid Graptolites—A Synopsis
Evolution of retiolitid graptolites—a synopsis ANNA KOZŁOWSKA−DAWIDZIUK Kozłowska−Dawidziuk A. 2004. Evolution of retiolitid graptolites—a synopsis. Acta Palaeontologica Polonica 49 (4): 505–518. Twenty million years of retiolitid evolution reflect environmental changes, the most severe being the Silurian Cyrto− graptus lundgreni Event. Five biostratigraphically and morphologically constrained retiolitid faunas are distinguished and characterized according to their rhabdosomal modifications: (1) the oldest and long−ranging Llandovery group of mostly large and morphologically complex rhabdosomes, (2) the less diverse Telychian−Sheinwoodian group, (3) the Cyrto− graptus lundgreni Biozone varied group of intermediate size, and two short−ranged (4) late Homerian, and (5) early Lud− low groups with small rhabdosomes. Although the evolutionary history of retiolitids was complex and not linear, a com− mon tendency toward reduction of rhabdosome size in most lineages is observed. The greatest reduction in both number and volume of thecae, and in skeletal elements is demonstrated in the Gothograptus and Plectograptus faunas. Contrary to the thecal decrease, a distinctive increase of sicula size is observed in retiolitids. Two types of colonies are distinguished: L−colonies with a small sicula and numerous large thecae of similar size, and S−colonies with a long sicula and a few, small thecae. These changes imply modification of the soft body: an increase in siculozooid length and a decrease in the size of the zooids. Thus, the siculozooid probably produced great amounts of morphogen inhibiting zooid growth. In consequence the phenomenon of colony reduction occurred. The most extreme stages of rhabdosome reduction in Ludlow retiolitids can be seen in Plectodinemagraptus gracilis of the Plectograptus lineage and in the new species Holoretiolites helenaewitoldi, possibly representing the last stage of skeletal reduction in the Gothograptus lineage; the next hypothetical stage would be its total loss. -
1465 Maletz.Vp
The classification of the Pterobranchia (Cephalodiscida and Graptolithina) JÖRG MALETZ This paper presents a proposal for a taxonomic approach to the classification of the Pterobranchia (Cephalodiscida and Graptolithina) to be adopted for the revision of the Treatise on Invertebrate Paleontology, Part V (Hemichordata), cur- rently in preparation. A combination of traditional Linnaean taxonomy, supported by cladistic analyses in some groups is proposed herein as a practical solution for the classification of the Graptolithina as for many groups a cladistic analy- sis has never been attempted and is unlikely to be undertaken in the near future. The number of ranked taxa has been kept as low as possible, with all genus level taxa referred to a family. All families and higher taxonomic units are discussed, but new taxa have not been introduced. Paraphyletic (but not polyphyletic) taxa are accepted as useful units in this classi- fication. A number of recently introduced taxonomic units, based on cladistic analyses (e.g. Eugraptoloida, Pan-Reclinata, Pan-Bireclinata), are discussed in the context of this classification and the usefulness of these taxa is criti- cally evaluated. The solution proposed here opts not to name a number of nodes from the published cladistic analyses that potentially could be named and in some cases have been named – not to inflate the hierarchy of the used taxonomic system. Taxa are kept as close as possible to their original definition and not unnecessarily expanded or restricted. The taxonomy proposed here for the Graptolithina indicates that the extensive use of higher level taxa, e.g. orders for small groups of genera as has been done for many benthic graptolite groups in the past is unnecessary and should be avoided.