DOCSLIB.ORG

Hydrozoan-Like Ediacaran Fossils from South China 华南伊迪卡拉纪类水母化石新发现

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

第 35 卷 第 1 期 地 质 通 报 Vol.35,No.1 2016 年 1 月 GEOLOGICAL BULLETIN OF CHINA Jan.,2016 Hydrozoan-like Ediacaran fossils from South China 华南伊迪卡拉纪类水母化石新发现 TANG Feng1,2, ZHONG Ling3, JIN Xingsheng4, GUO Donghui5, YIN Chongyu1,2 唐 烽 1,2，钟 玲 3，金幸生 4，郭东辉 5，尹崇玉 1,2 1.国土资源部地层与古生物重点实验室，北京 100037； 2.中国地质科学院地质研究所，北京 100037； 3.四川省博物院，四川 成都 610071； 4.浙江省自然历史博物馆，浙江 杭州 310014； 5.厦门大学海洋环境科学学院，福建 厦门 361005 1. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China; 2. Key Laboratory of Stratigraphy and Paleontology, Ministry of Land and Resources, Beijing 100037, China; 3. Sichuan Museum, Chengdu 610071, Sichuan, China; 4. Zhejiang Museum of Natural History, Hangzhou 310014, Zhejiang, China; 5. College of Oceanography & Environmental Science, Xiamen University, Xiamen 361005, Fujian, China Tang F, Zhong L, Jin X S, Guo D H, Yin C Y. Hydrozoan-like Ediacaran fossils from South China. Geological Bulletin of China, 2015, 35(1):1-9 Abstract: An abundant and diversified assemblage of benthic fossils from the Ediacaran Doushantuo black shales in the Wenghui sec⁃ tion of Guizhou Province contains two discoidal carbonaceous forms, Kullingia rotadiscopsis sp. nov. and Eoaequorea xingi gen. & sp. nov. The fossils have well-preserved concentric rings and radiating lines, and resemble many circular casts and moulds in Edia⁃ caran clastic and carbonate rocks in the world, such as Aspidella, Ediacaria, Cyclomedusa, Eoporpita, Ovatoscutum, Spriggia and Kull⁃ ingia. The Doushantuo carbonaceous macrofossils help us to inquire into the current functional identifications of circular disks as the holdfasts of unknown organism or scratch circles. Although there is not sufficient correspondence in morphology to warrant reinter⁃ preting all previously described Kullingia and Aspidella form-genus-type structures, these carbonaceous compressions are prone to be the ancestor of pelagic jellyfish-like organisms with medusoid hydrozoan affinity. Key words: Ediacara; discoidal macrofossils; South China; medusoid organisms 摘要：华南黔东北地区伊迪卡拉系陡山沱组黑色页岩中产出丰富多样的海相底栖宏体化石组合，其中包含2个新属种Kullingia rotadiscopsis sp. nov. 和 Eoaequorea xingi gen. & sp. nov.。新类别具有保存清晰的碳质同心环纹和辐射状纹饰，形态上相似于国外 广泛分布在碎屑岩和碳酸盐岩中的伊迪卡拉纪典型的圆盘状化石，例如Aspidella, Ediacaria, Cyclomedusa, Eoporpita, Ovatoscutum, Spriggia, Kullingia等。上述化石在国外几乎都保存为印痕，近年来多被解释为不明亲缘底栖生物的圆形固着痕迹或抓痕、圆环状 扫痕等，华南陡山沱组碳质压膜保存的圆盘状宏体化石显然不支持该解释。目前，还没有充分的证据表明华南新发现的碳膜化石 与国外形态类似的印痕化石如Kullingia和Aspidella具有相同的亲缘关系，但支持将华南化石归属为可能最早的浮游型水螅水母。 关键词：伊迪卡拉纪；圆盘状宏体化石；华南；似水母生物 中图分类号：P534.41；Q915.2 文献标志码：A 文章编号：1671-2552（2016）01-0001-09 Received on December 9, 2014；accepted on July 1, 2015; published on Junuary 15, 2016 This project supported by the National Natural Science Foundations of China (No.41172002, 41162003, 41572024) and the China Geology Survey (No.1212011120140-1) Author: TANG Feng(1965- ), male, Ph.D, Professor. E-mail: [email protected] 2 地 质 通 报 GEOLOGICAL BULLETIN OF CHINA 2016 年 caran fronds, such as Charniodiscus with Charnia. 1 Introduction They have even been interpreted as marine fungi or Discoidal carbonaceous compressions are compara⁃ microbial mats[17- 18], as well as trace fossils[19- 20]. Disk- tively rare in the black shales of the Ediacaran/Sinian like concentric grooves and ridges have rather been Doushantuo Formation, South China, with the excep⁃ explained as tool marks or scratch circles formed by tion of the mass- buried Beltanelliformis[1] reported current rotation of benthic pennatulids or tube-form⁃ previously[2]. They are, however, abundant in many ing animals (e.g., sabelliditids)[21]. Ediacara deposits in Newfoundland, England, Austra⁃ This paper reports carbonaceous compressions lia, Canada, Russia, India and other European areas- with well- preserved concentric and radial structures discoidal imprint macrofossils occur rather frequently (Plate Ⅰ, Ⅱ) from the Late Ediacaran Doushantuo as moulds and casts in coarse siliclastic and carbonate shales in Southern China. The compressions show sediments. The wide distribution and diversity of close resemblance to the discoidal Ediacaran imprint these forms has led to different views and interpreta⁃ fossils. The fossils are interpreted at least in part to tions of their phylogeny and ecology[3- 7]. Their con⁃ possibly represent free- swimming soft- bodied ma⁃ centric and radial grooves and ridges originally result⁃ rine animals with discoidal or medusoidal outlines. ed in allocation to planktonic medusoid cnidarians[8-9], The identical fossiliferous beds in the Doushantuo but later many palaeontologists[3,10- 16] interpreted them Formation also bear abundant tentacle- like carbona⁃ as attachment structures of benthic frondose organ⁃ ceous compressions (Fig.1- a,b), which implies the isms because of the preservation of a holdfast- stalk previous proposals of medusoid affinity of the Edia⁃ continuum or some discoidal fossils with typical Edia⁃ caran discoidal macrofossils. PlateⅠ a. holotype of Kullingia rotadiscopsis, M; b. sketching image of a; c. counterpart of a, ZMNH M10072 ; d~f. close up of a and c, noted the perfect concentric ribbons (d) in the upper part of a, the uncertain neckline structures (e) in the right part of a and the central part of c (f). The minimum scale is 1mm. cr—carbonaceous ring; az—axis-like zone; n—notch; h—hollow 第 35 卷 第 1 期 TANG Feng et al: Hydrozoan-like Ediacaran fossils from South China 3 Etymology:The generic name derives from eos, 2 Results dawn, and Aequorea, a modern genus of hydrozoan 2.1 Systematic palaeontology medusae. The specific name is dedicated to Professor Phylum Cnidaria Yusheng Xing, Feng Tang’s Ph.D. teacher in CAGS Class Hydrozoa (Chinese Academy of Geological Sciences, Beijing). Order and Family ? uncertain Material：Two separate specimens in part and Genus Kullingia Glaessner, 1974 counterpart, one nearly complete disc and the other New species Kullingia rotadiscopsis sp. nov. with the central area abraded away. Specimen num⁃ (Plate Ⅰ-a~f ) bers: ZMNH M10073,M10074. Etymology: The specific name derives from Type species：Eoaequorea xingi sp. nov. rota, wheel, discus disk, and -opsis, like. The name al⁃ Generic diagnosis：Disc flat, circular to sub-cir⁃ ludes directly to the similarity with the Cambrian cular, with numerous straight, simple and unbranched Chengjiang genus Rotadiscus Sun and Hou[22], 1987. radial striations from center to fringe, distinct concen⁃ Material: One nearly complete disc in part and tric rings and finer annular lines. counterpart. Specimen number: ZMNH M10072 Holotype Plate Ⅱ- b, c; Number: ZMNH (Zhejiang Museum of Natural History, Hangzhou, M10074. China). Horizon and locality：Ediacaran, Doushantuo Holotype Plate I-a, c. Formation, layer 13; Wenghui, Jiangkou, Guizhou, Horizon and locality: Ediacaran, Doushantuo China. Formation, layer 13; Wenghui, Jiangkou, Guizhou, Description：Disc flat, circular to sub- circular, China. about 2-3 cm in diameter; carbonaceous radial stria⁃ Diagnostic: Disc large, radially symmetric, with⁃ tions, numerous, straight and unbranched, from center out radial canals or striations, and with concentric car⁃ to fringe, spaced at most 1.3 mm in the outmost part bonaceous ribbon-like rings. but often much closer together in peripheral zone Description: Circular to ovoid in shape, about (Plate Ⅱ-a,b); 3-6 carbonaceous concentric ringscon⁃ 5.3 cm in maximum diameter; up to 25 concentric tained respectively in three zones(Plate Ⅱ- b,h) or carbonaceous rings from centre to fringe; showing de⁃ wrinkles, irregular and incomplete in the outer part, centralized slightly on outer part and ca.1.7- 2.0 mm darker on peripheral margins; inconspicuous and fine between each circle(Plate Ⅰ-d), whereas on the cen⁃ annular lines in the inner half showing partially cob⁃ tral part relatively dense(Plate Ⅰ- f). Rounded shape web-like structure(Plate Ⅱ-a,e,f) together with circu⁃ interrupted by a small uncertain neckline- like notch lar and radial striations; black carbonaceous ring about on one outer side showing about 3 ribbons sinuous 1-1.6 mm wide in center of disc with a 1.2 mm hol⁃ and closed (Plate Ⅰ-a,b,e). A black, not readily appar⁃ low(Plate Ⅱ-h) lacking carbonaceous film. ent axis-like zone about 2 mm wide extends through 2.2 Comparison with other taxa the center on the surface of the disc possibly due to ev⁃ (1) Kullingia rotadiscopsis ery concentric ribbons thicken. Kullingia is a circular imprint disk with sets of Phylum Cnidaria concentric rings from Late Ediacaran to Early Cambri⁃ Class Hydrozoa an of South Australia, Newfoundland, Ukraine and Order and family uncertain northern Sweden. It was initially interpreted as a chon⁃ New genus and species Eoaequorea xingi gen. drophorine hydrozoan[23], but is currently thought to and sp. nov. be a scratch circle, possibly of an anchored, tubular or⁃ (Plate Ⅱ-a~e) ganism[21]. Regular and dense concentric lines, and 4 地 质 通 报 GEOLOGICAL BULLETIN OF CHINA 2016 年 Plate Ⅱ a. paratype of Eoaequorea Xingi, ZMNH M10073, noted the black central ring with some abrasion; b. field photograph of c; c. holotype of Eoaequorea Xingi, ZMNH M10074; d. counterpart of a; e. right-upper close up of a; f,h. sketching images of a and c; g. holdfast of macroscopic algae fossils, ZMNH M10075. The minimum scale is 1mm. rs—radial striation; oz—outer zone; mz—middle zone; pz—peripheral zone; cr—carbonaceous ring; cz—central zone; h—hollow; cs—cobweb-like structure lack of radial ones, can be seen on the rounded carbo⁃ apparently has three concentric zones[13,24]. Ovatoscu⁃ naceous film described here as K. rotadiscopsis. It is tum in the Rawnsley Quartzite,
Recommended publications
  • The Ediacaran Frondose Fossil Arborea from the Shibantan Limestone of South China

    The Ediacaran Frondose Fossil Arborea from the Shibantan Limestone of South China

    Journal of Paleontology, 94(6), 2020, p. 1034–1050 Copyright © 2020, The Paleontological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. 0022-3360/20/1937-2337 doi: 10.1017/jpa.2020.43 The Ediacaran frondose fossil Arborea from the Shibantan limestone of South China Xiaopeng Wang,1,3 Ke Pang,1,4* Zhe Chen,1,4* Bin Wan,1,4 Shuhai Xiao,2 Chuanming Zhou,1,4 and Xunlai Yuan1,4,5 1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing 210008, China <[email protected]><[email protected]> <[email protected]><[email protected]><[email protected]><[email protected]> 2Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA <[email protected]> 3University of Science and Technology of China, Hefei 230026, China 4University of Chinese Academy of Sciences, Beijing 100049, China 5Center for Research and Education on Biological Evolution and Environment, Nanjing University, Nanjing 210023, China Abstract.—Bituminous limestone of the Ediacaran Shibantan Member of the Dengying Formation (551–539 Ma) in the Yangtze Gorges area contains a rare carbonate-hosted Ediacara-type macrofossil assemblage. This assemblage is domi- nated by the tubular fossil Wutubus Chen et al., 2014 and discoidal fossils, e.g., Hiemalora Fedonkin, 1982 and Aspidella Billings, 1872, but frondose organisms such as Charnia Ford, 1958, Rangea Gürich, 1929, and Arborea Glaessner and Wade, 1966 are also present.
  • Ediacaran) of Earth – Nature’S Experiments

    Ediacaran) of Earth – Nature’S Experiments

    The Early Animals (Ediacaran) of Earth – Nature’s Experiments Donald Baumgartner Medical Entomologist, Biologist, and Fossil Enthusiast Presentation before Chicago Rocks and Mineral Society May 10, 2014 Illinois Famous for Pennsylvanian Fossils 3 In the Beginning: The Big Bang . Earth formed 4.6 billion years ago Fossil Record Order 95% of higher taxa: Random plant divisions domains & kingdoms Cambrian Atdabanian Fauna Vendian Tommotian Fauna Ediacaran Fauna protists Proterozoic algae McConnell (Baptist)College Pre C - Fossil Order Archaean bacteria Source: Truett Kurt Wise The First Cells . 3.8 billion years ago, oxygen levels in atmosphere and seas were low • Early prokaryotic cells probably were anaerobic • Stromatolites . Divergence separated bacteria from ancestors of archaeans and eukaryotes Stromatolites Dominated the Earth Stromatolites of cyanobacteria ruled the Earth from 3.8 b.y. to 600 m. [2.5 b.y.]. Believed that Earth glaciations are correlated with great demise of stromatolites world-wide. 8 The Oxygen Atmosphere . Cyanobacteria evolved an oxygen-releasing, noncyclic pathway of photosynthesis • Changed Earth’s atmosphere . Increased oxygen favored aerobic respiration Early Multi-Cellular Life Was Born Eosphaera & Kakabekia at 2 b.y in Canada Gunflint Chert 11 Earliest Multi-Cellular Metazoan Life (1) Alga Eukaryote Grypania of MI at 1.85 b.y. MI fossil outcrop 12 Earliest Multi-Cellular Metazoan Life (2) Beads Horodyskia of MT and Aust. at 1.5 b.y. thought to be algae 13 Source: Fedonkin et al. 2007 Rise of Animals Tappania Fungus at 1.5 b.y Described now from China, Russia, Canada, India, & Australia 14 Earliest Multi-Cellular Metazoan Animals (3) Worm-like Parmia of N.E.
  • The Evolution of Siphonophore Tentilla for Specialized Prey Capture in the Open Ocean

    The Evolution of Siphonophore Tentilla for Specialized Prey Capture in the Open Ocean

    The evolution of siphonophore tentilla for specialized prey capture in the open ocean Alejandro Damian-Serranoa,1, Steven H. D. Haddockb,c, and Casey W. Dunna aDepartment of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520; bResearch Division, Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039; and cEcology and Evolutionary Biology, University of California, Santa Cruz, CA 95064 Edited by Jeremy B. C. Jackson, American Museum of Natural History, New York, NY, and approved December 11, 2020 (received for review April 7, 2020) Predator specialization has often been considered an evolutionary makes them an ideal system to study the relationships between “dead end” due to the constraints associated with the evolution of functional traits and prey specialization. Like a head of coral, a si- morphological and functional optimizations throughout the organ- phonophore is a colony bearing many feeding polyps (Fig. 1). Each ism. However, in some predators, these changes are localized in sep- feeding polyp has a single tentacle, which branches into a series of arate structures dedicated to prey capture. One of the most extreme tentilla. Like other cnidarians, siphonophores capture prey with cases of this modularity can be observed in siphonophores, a clade of nematocysts, harpoon-like stinging capsules borne within special- pelagic colonial cnidarians that use tentilla (tentacle side branches ized cells known as cnidocytes. Unlike the prey-capture apparatus of armed with nematocysts) exclusively for prey capture. Here we study most other cnidarians, siphonophore tentacles carry their cnidocytes how siphonophore specialists and generalists evolve, and what mor- in extremely complex and organized batteries (3), which are located phological changes are associated with these transitions.
  • OREGON ESTUARINE INVERTEBRATES an Illustrated Guide to the Common and Important Invertebrate Animals

    OREGON ESTUARINE INVERTEBRATES an Illustrated Guide to the Common and Important Invertebrate Animals

    OREGON ESTUARINE INVERTEBRATES An Illustrated Guide to the Common and Important Invertebrate Animals By Paul Rudy, Jr. Lynn Hay Rudy Oregon Institute of Marine Biology University of Oregon Charleston, Oregon 97420 Contract No. 79-111 Project Officer Jay F. Watson U.S. Fish and Wildlife Service 500 N.E. Multnomah Street Portland, Oregon 97232 Performed for National Coastal Ecosystems Team Office of Biological Services Fish and Wildlife Service U.S. Department of Interior Washington, D.C. 20240 Table of Contents Introduction CNIDARIA Hydrozoa Aequorea aequorea ................................................................ 6 Obelia longissima .................................................................. 8 Polyorchis penicillatus 10 Tubularia crocea ................................................................. 12 Anthozoa Anthopleura artemisia ................................. 14 Anthopleura elegantissima .................................................. 16 Haliplanella luciae .................................................................. 18 Nematostella vectensis ......................................................... 20 Metridium senile .................................................................... 22 NEMERTEA Amphiporus imparispinosus ................................................ 24 Carinoma mutabilis ................................................................ 26 Cerebratulus californiensis .................................................. 28 Lineus ruber .........................................................................
  • Back Matter (PDF)

    Back Matter (PDF)

    Index Acraman impact ejecta layer 53–4, 117, 123, 126–9, Aspidella 130–2, 425–7 controversy 300, 301–3, 305 acritarchs ecology 303 Amadeus and Officer Basins 119 synonyms 302 biostratigraphy 115–25, 130–2 Australia Australian correlations 130–2 Acraman impact ejecta layer 53–4, 117, 123, 126–9, composite zonation scheme 119, 131, 132 130–2, 425–7 India 318–20 carbon isotope chemostratigraphy 126–9 Ireland 289 correlations of Ediacaran System and Period 18, Spain 232 115–35 sphaeromorphid 324 Marinoan glaciation 53–4, 126 Adelaide, Hallett Cove 68 Australia, Ediacaran System and Period Adelaide Rift Complex 115–22, 425 Bunyeroo–Wonoka Formation transition correlations with Officer Basin 127 137–9, 426 dating (Sr–Rb) 140 Centralian Superbasin 118, 125 generalized time–space diagram, correlations composite zonation scheme 131 between tectonic units 120 correlation methods and results 125–32 location maps 116, 118 time–space diagram 120 SE sector cumulative strata thickness 139 Vendian climatic indicators 17 stratigraphic correlation with Officer Basin 127 See also Adelaide Rift Complex; Flinders Ranges Stuart Shelf drill holes, correlations 117 Avalonian assemblages, Newfoundland 237–57, Sturtian (Umberatana) Group 116, 138 303–7, 427 Umberatana Group 116, 138 Africa backarc spreading, Altenfeld Formation 44–5, 47–8 Vendian climatic indicators 17 Baliana–Krol Group, NW Himalaya 319 see also Namibia Barut Formation, Iran 434 Aldanellidae 418 Bayesian analysis algal metaphyta, White Sea Region 271–4 eumetazoans 357–9 algal microfossils, White
  • Journ Al of Re Search in Biology

    Journ Al of Re Search in Biology

    Journal of Research in Biology ISSN No: Print: 2231 –6280; Online: 2231- 6299 An International Scientific Research Journal Original Research Notes on the occurrence of Porpita porpita (Blue button) from Pulicat Lagoon Authors: ABSTRACT: * Ravichandran Ramanibai , Sivalingam Govindan and Thamotharan Balakrishnan We spotted the presence of blue buttons washed ashore during the month of Institution: December 2013 in Pulicat lagoon. These rare sited organisms were observed during Unit of Aquatic Biodiversity, our regular faunal field visit along the Pulicat lagoon. Department of Zoology, University of Madras, Guindy campus, Chennai, Tamil Nadu -600 025, India. Corresponding author: Keywords: Ravichandran Ramanibai Hydrozoans, Porpita porpita, Pulicat lagoon Email Id: Article Citation: Ravichandran Ramanibai, Sivalingam Govindan and Thamotharan Balakrishnan Journal of Research in Biology Notes on the occurrence of Porpita porpita (Blue button) from Pulicat Lagoon Journal of Research in Biology (2014) 4(7): 1487-1490 Dates: Web Address: Received: 21 Jul 2014 Accepted: 19 Aug 2014 Published: 07 Nov 2014 http://jresearchbiology.com/ documents/RA0465.pdf This article is governed by the Creative Commons Attribution License (http://creativecommons.org/ licenses/by/4.0), which gives permission for unrestricted use, non-commercial, distribution and reproduction in all medium, provided the original work is properly cited. 1487-1490 | JRB | 2014 | Vol 4 | No 7 Journal of Research in Biology An International Scientific Research Journal www.jresearchbiology.com Ramanibai et al., 2014 INTRODUCTION reproduction P. porpita is hard, slightly convex disc, Blue buttons were seen in Pulicat lagoon during golden brown, gas-filled float in the centre, blue, yellow the post-monsoon season of the year 2013.
  • High Ecological Complexity in Benthic Ediacaran Communities

    High Ecological Complexity in Benthic Ediacaran Communities

    ARTICLES https://doi.org/10.1038/s41559-018-0663-7 High ecological complexity in benthic Ediacaran communities Simon A. F. Darroch 1*, Marc Laflamme2 and Peter J. Wagner3 A long-running debate over the affinities of the Neoproterozoic ‘Ediacara biota’ has led to contrasting interpretations of Ediacaran ecosystem complexity. A ‘simple’ model assumes that most, if not all, Ediacaran organisms shared similar basic ecologies. A contrasting ‘complex’ model suggests that the Ediacara biota more likely represent organisms from a variety of different positions on the eukaryotic tree and thus occupied a wide range of different ecologies. We perform a quantitative test of Ediacaran ecosystem complexity using rank abundance distributions (RADs). We show that the Ediacara biota formed complex-type communities throughout much of their stratigraphic range and thus likely comprised species that competed for different resources and/or created niche for others (‘ecosystem engineers’). One possible explanation for this pattern rests in the recent inference of multiple metazoan-style feeding modes among the Ediacara biota; in this scenario, different Ediacaran groups/clades were engaged in different methods of nutrient collection and thus competed for different resources. This result illustrates that the Ediacara biota may not have been as bizarre as it is sometimes suggested, and provides an ecological link with the animal-dominated benthic ecosystems of the Palaeozoic era. he terminal Neoproterozoic Ediacara biota (570–541 Ma) number of basic resource types being partitioned13. One class of represents the first major radiation of large, morphologically RAD models supposes that species in a community compete for complex multicellular eukaryotes. Given their position at the roughly the same resources.
  • CNIDARIA Corals, Medusae, Hydroids, Myxozoans

    CNIDARIA Corals, Medusae, Hydroids, Myxozoans

    FOUR Phylum CNIDARIA corals, medusae, hydroids, myxozoans STEPHEN D. CAIRNS, LISA-ANN GERSHWIN, FRED J. BROOK, PHILIP PUGH, ELLIOT W. Dawson, OscaR OcaÑA V., WILLEM VERvooRT, GARY WILLIAMS, JEANETTE E. Watson, DENNIS M. OPREsko, PETER SCHUCHERT, P. MICHAEL HINE, DENNIS P. GORDON, HAMISH J. CAMPBELL, ANTHONY J. WRIGHT, JUAN A. SÁNCHEZ, DAPHNE G. FAUTIN his ancient phylum of mostly marine organisms is best known for its contribution to geomorphological features, forming thousands of square Tkilometres of coral reefs in warm tropical waters. Their fossil remains contribute to some limestones. Cnidarians are also significant components of the plankton, where large medusae – popularly called jellyfish – and colonial forms like Portuguese man-of-war and stringy siphonophores prey on other organisms including small fish. Some of these species are justly feared by humans for their stings, which in some cases can be fatal. Certainly, most New Zealanders will have encountered cnidarians when rambling along beaches and fossicking in rock pools where sea anemones and diminutive bushy hydroids abound. In New Zealand’s fiords and in deeper water on seamounts, black corals and branching gorgonians can form veritable trees five metres high or more. In contrast, inland inhabitants of continental landmasses who have never, or rarely, seen an ocean or visited a seashore can hardly be impressed with the Cnidaria as a phylum – freshwater cnidarians are relatively few, restricted to tiny hydras, the branching hydroid Cordylophora, and rare medusae. Worldwide, there are about 10,000 described species, with perhaps half as many again undescribed. All cnidarians have nettle cells known as nematocysts (or cnidae – from the Greek, knide, a nettle), extraordinarily complex structures that are effectively invaginated coiled tubes within a cell.
  • A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils

    A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils

    Provided by the author(s) and NUI Galway in accordance with publisher policies. Please cite the published version when available. Title A Solution to Darwin's Dilemma: Differential Taphonomy of Ediacaran and Palaeozoic Non-Mineralised Discoidal Fossils Author(s) MacGabhann, Breandán Anraoi Publication Date 2012-08-29 Item record http://hdl.handle.net/10379/3406 Downloaded 2021-09-26T20:57:04Z Some rights reserved. For more information, please see the item record link above. A Solution to Darwin’s Dilemma: Differential taphonomy of Palaeozoic and Ediacaran non- mineralised discoidal fossils Volume 1 of 2 Breandán Anraoi MacGabhann Supervisor: Dr. John Murray Earth and Ocean Sciences, School of Natural Sciences, NUI Galway August 2012 Differential taphonomy of Palaeozoic and Ediacaran non-mineralised fossils Table of Contents List of Figures ........................................................................................................... ix List of Tables ........................................................................................................... xxi Taxonomic Statement ........................................................................................... xxiii Acknowledgements ................................................................................................ xxv Abstract ................................................................................................................. xxix 1. Darwin’s Dilemma ...............................................................................................
  • Guide to Estuarine and Inshore Bivalves of Virginia

    Guide to Estuarine and Inshore Bivalves of Virginia

    W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1968 Guide to Estuarine and Inshore Bivalves of Virginia Donna DeMoranville Turgeon College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Marine Biology Commons, and the Oceanography Commons Recommended Citation Turgeon, Donna DeMoranville, "Guide to Estuarine and Inshore Bivalves of Virginia" (1968). Dissertations, Theses, and Masters Projects. Paper 1539617402. https://dx.doi.org/doi:10.25773/v5-yph4-y570 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. GUIDE TO ESTUARINE AND INSHORE BIVALVES OF VIRGINIA A Thesis Presented to The Faculty of the School of Marine Science The College of William and Mary in Virginia In Partial Fulfillment Of the Requirements for the Degree of Master of Arts LIBRARY o f the VIRGINIA INSTITUTE Of MARINE. SCIENCE. By Donna DeMoranville Turgeon 1968 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts jfitw-f. /JJ'/ 4/7/A.J Donna DeMoranville Turgeon Approved, August 1968 Marvin L. Wass, Ph.D. P °tj - D . dvnd.AJlLJ*^' Jay D. Andrews, Ph.D. 'VL d. John L. Wood, Ph.D. William J. Hargi Kenneth L. Webb, Ph.D. ACKNOWLEDGEMENTS The author wishes to express sincere gratitude to her major professor, Dr.
  • Exceptionally Preserved Jellyfishes from the Middle Cambrian Paulyn Cartwright1, Susan L

    Exceptionally Preserved Jellyfishes from the Middle Cambrian Paulyn Cartwright1, Susan L

    Exceptionally Preserved Jellyfishes from the Middle Cambrian Paulyn Cartwright1, Susan L. Halgedahl2, Jonathan R. Hendricks3, Richard D. Jarrard2, Antonio C. Marques4, Allen G. Collins5, Bruce S. Lieberman3* 1 Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America, 2 Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, United States of America, 3 Department of Geology, and Division of Invertebrate Paleontology, Natural History Museum, University of Kansas, Lawrence, Kansas, United States of America, 4 Departamento de Zoologia, Instituto de Biocieˆncias, Universidade de Sa˜o Paulo, Sa˜o Paulo, Sa˜o Paulo, Brazil, 5 National Systematics Laboratory of NOAA Fisheries Service, National Museum of Natural History, Smithsonian Institution, Washington, D. C., United States of America Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (,505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish taxa. These new discoveries may provide insight into the scope of cnidarian diversity shortly after the Cambrian radiation, and would reinforce the notion that important taxonomic components of the modern planktonic realm were in place by the Cambrian period.
  • New Ediacara Fossils Preserved in Marine Limestone and Their Ecological Implications

    New Ediacara Fossils Preserved in Marine Limestone and Their Ecological Implications

    OPEN New Ediacara fossils preserved in SUBJECT AREAS: marine limestone and their ecological PALAEONTOLOGY GEOLOGY implications Zhe Chen1, Chuanming Zhou1, Shuhai Xiao2, Wei Wang1, Chengguo Guan1, Hong Hua3 & Xunlai Yuan1 Received 22 November 2013 1LPS and LESP, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China, Accepted 2Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA, 3State Key Laboratory 7 February 2014 of Continental Dynamics and Department of Geology, Northwest University, Xi’an 710069, China. Published 25 February 2014 Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and Correspondence and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an requests for materials erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551– should be addressed to 541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of Z.C. (zhechen@ several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or nigpas.ac.cn) or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. S.H.X. ([email protected]) he Ediacara biota, exemplified by fossils preserved in the Ediacara Member of South Australia, provides key information about the origin, diversification, and disappearance of a distinct group of soft-bodied, mac- T roscopic organisms on the eve of the Cambrian diversification of marine animals1–3.