DOCSLIB.ORG

A New Middle Cambrian Stem-Group

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A New Middle Cambrian Stem-Group A new Middle Cambrian stem−group echinoderm from Spain: Palaeobiological implications of a highly asymmetric cinctan SAMUEL ZAMORA and ANDREW B. SMITH Zamora, S. and Smith, A.B. 2008. A new Middle Cambrian stem−group echinoderm from Spain: Palaeobiological impli− cations of a highly asymmetric cinctan. Acta Palaeontologica Polonica 53 (2): 207–220. A new exquisitely preserved stem group echinoderm (cinctan), Lignanicystis barriosensis gen. et sp. nov., is described from the Middle Cambrian of Los Barrios de Luna, North Spain. This displays a unique asymmetrical body plan with ven− tral projecting nodes that raised the lower surface above the substratum. There are four openings through the body wall: mouth, anus, atrium, and an aligned row of sutural pores of uncertain function. Unlike other cinctans, Lignanicystis has a strongly asymmetrical shape convergent with that of some cornute carpoids. Like cornutes, the test is also elevated above the substratum to allow water flow beneath the theca. In both cases this is probably an adaptation to life in higher water flow regimes. Key words: Echinodermata, Homostelea, carpoids, functional morphology, Cambrian, Spain. Samuel Zamora [[email protected]], Área y Museo de Paleontología, Departamento de Ciencias de la Tierra, Univer− sidad de Zaragoza, E−50009 Zaragoza, Spain; Andrew B. Smith [[email protected]], Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK. Introduction The first cinctan was described by Barrande from the Mid− dle Cambrian of Bohemia (Czech Republic) (Barrande 1887). In the Lower Palaeozoic a group of problematic fossils termed He considered them to be primitive stalked echinoderms. carpoids have long intrigued palaeontologists. These have a However, as they became better known and the uniqueness of multiplated skeleton constructed of calcite with a very distinc− their anatomical organization began to be appreciated, they tive microstructural arrangement termed stereom. The genes were first raised to ordinal level within the class Carpoidea responsible for stereom are unique to echinoderms amongst (Jaekel 1918) then elevated to their own subclass then class living phyla (Bottjer et al. 2006). However, carpoids differ Homostelea (Gill and Caster 1960; Ubaghs 1968). Friedrich from all living echinoderms in lacking any trace of radial sym− (1993) has provided a detailed review of the nomenclatorial metry, and have a strange anatomy that has been interpreted in history of the Carpoidea and resurrected the name Cincta several contrasting ways. Furthermore, some carpoids also ap− Jaekel, 1918 for this group. Currently there are 12 genera and pear to lack ambulacra, one of the defining features of crown 24 species of cinctans, all from the Middle Cambrian of West− group echinoderms. For these reasons carpoids have proved ern Gondwana, Avalonia, and Siberia (Friedrich 1993, 1995; contentious. Sdzuy 1993; Fatka and Kordule 2001; Rozhnov 2006). Fried− There are four major groups of carpoids: stylophorans, rich (1993) and Sdzuy (1993) have all published detailed de− ctenocystoids, cinctans, and solutes, all of which remain scriptive studies of the group and both accepted cinctans to be somewhat enigmatic. Cinctans, the subject of this paper, are primitive echinoderms. known only from the Middle Cambrian. They are generally Because of their unusual morphology, the phylogenetic small and shaped like a tennis racquet with a plano−convex relationships of cinctans have been much debated. They have body (theca) and a posterior appendage (stele). A ring of variously been interpreted as primitive, pre−radiate stem− large marginal plates forms a stout frame (cinctus) to the group echinoderms (Bather 1930; Ubaghs 1971, 1975; Jef− theca. Inside this frame the body is enclosed by dorsal and feries et al. 1996; Smith 2005), as stem−group Hemichordata ventral plated integuments composed of small, tesselated (Domínguez and Jefferies 2005), or as unusual eocrinoid plates. The body is pierced by several openings, some pass− echinoderms that have secondarily lost their pentamery (Da− ing through the marginal frame, others through the dorsal in− vid et al. 2000). Nor is there general consensus about their tegument. An asymmetrical pair of grooves leads into one of anatomy or mode of life, with the large opening at the ante− the marginal openings that is commonly assumed to be the rior being interpreted as a mouth (e.g., Termier and Termier mouth. 1973), anus (e.g., Ubaghs 1968) or atrial opening to a pha− Acta Palaeontol. Pol. 53 (2): 207–220, 2008 http://app.pan.pl/acta53/app53−207.pdf 208 ACTA PALAEONTOLOGICA POLONICA 53 (2), 2008 Mesozoic–Tertiary cover unconformable Stephanian rocks West Asturian–Leonese Zone Precambrian rocks (Narcea Antiform) Cantabrian Zone Los Barrios Facies distribution area Belen o Facies distribution area areas without Cambian outcrops 0102030 km Oviedo Los Barrios de Luna Fig. 1. A. Geographic map of Spain with the situation of Cantabrian Mountains. B. Geological setting of the section studied in Los Barrios de Luna (Cantabrian Mountains, North Spain). Based on Sdzuy and Liñán (1993). ryngeal chamber (e.g., Bonik et al. 1978; Friedrich 1993; Institutional abbreviation.—MPZ, Museo Paleontológico, Smith 2005). The most widely held current view is that Universidad de Zaragoza, Spain. cinctans were active suspension feeders with their ventral surface resting on the sea floor, and with their slightly flexi− ble appendage, upstream of the body, acting as an anchor in Geological setting soft substrata (Friedrich 1993). Cinctans probably fed by fil− tering out fine particles through some form of pharyngeal All the specimens of Lignanicystis barriosensis gen. et sp. basket, in an analogous way to extant tunicates (Bonik et al. nov. were collected from outcrops around the village of Los 1978; Sdzuy 1985; Smith 2005). Barrios de Luna in the Cantabrian Mountains, North Spain, New, excellently preserved material of a new species of about 50 km northwest of the city of León (Fig. 1). The Cam− cinctan, Lignanicystis barriosensis gen. et sp. nov., has been brian rocks cropping out here range from the early to late collected from the late Middle Cambrian of Spain and pro− Cambrian in a continuous section called Los Barrios de Luna vides new information on the morphology and palaeobiology 1 (BL−1). They were deposited under marine conditions in of this enigmatic group. This new cinctan genus is unusual in the western margin of Gondwana. The Lower Cambrian having a highly asymmetrical theca, convergent in overall Herrería Formation is a siliciclastic succession that discor− shape with cothurnocystid and ceratocystid stylophoran car− dantly overlies the Upper Proterozoic Mora Formation. poids. This raises the prospect that all three taxa were adapted Above this come the Láncara (150 m thick deposits, Lower– for a similar mode of life and it is worth examining from a Middle Cambrian) and Oville (413 m thick deposits, Middle functional morphological perspective, what this might have Cambrian) Formations, the former comprising a monotonous been. Here we first describe the morphology of this new succession of purple carbonates (“griotte facies”) and the lat− cinctan and then consider what it tells us about cinctan palaeo− ter a siliciclastic succession of shales and sandstones divided biology. into three members (called Genestosa, Adrados, and La ZAMORA AND SMITH—NEW CINCTAN ECHINODERM FROM CAMBRIAN OF SPAIN 209 or partially articulated. The new cinctan described here comes from a thin level of siltstone at the base of the Genestosa Mem− Upper Cambrian La Matosa Member Barrios Formation ber of the Oville Formation (Fig. 2) where the only fossils are sandstone with pebbles trilobites belonging to the species Bailiella barriensis and sandstone and siltstone trace fossils. This horizon belongs to the Solenopleuropsis shales thorali Zone, Lower Languedocian (early Middle Cambrian). kaolinite The lithofacies and palaeontological evidence suggests a rela− tively shallow sublittoral environment of low to moderate en− limestone ergy, sporadically affected by storms. The presence of key tri− oolithic limestone lobite taxa and archaeocyathans suggest a subtropical palae− limestone with birdeseyes olatitude (Courjault−Radé et al. 1992; Gozalo et al. 2003). La Barca Member limestone with nodules dolostone Astropolichnus Systematic palaeontology stromatolites Phylum Echinodermata Brugière, 1791 Languedocian Oville Formation trilobites (Stem group of the Echinodermata) inarticulated brachiopods Middle Cambrian Cincta Jaekel, 1918 articulated brachiopods Family Trochocystitidae Jaekel, 1900 Adrados Member echinoderms Genus Lignanicystis nov. Derivation of the name: Named in honour of Prof. Eladio Liñán (Uni− versidad de Zaragoza, Spain) in recognition of his lifetime dedication to the study of Spanish Cambrian fossils. Type species: Lignanicystis barriosensis sp. nov., monotypic. CA Memeber Genestosa Diagnosis.—A cinctan whose theca is strongly asymmetrical Upper in shape; anterior margin very wide and nearly straight; mar− Mb. ginal plates M4r to M6r form an indented, bridge−like struc− LE ture. Upper tegument of plates (supracentrals) differentiated into two discrete areas, the anterior central area formed of larger plates without pits or pores, the posterior and marginal areas of smaller plates with stellate ornamentation; an arc of á Lower Member L ncara Formation small openings is developed towards the left side of the supra− centralia separating these
Load more

Recommended publications
  • Zamora, S., Rahman, IA, & Smith, AB (2012). Plated Cambrian
    Zamora, S., Rahman, I. A., & Smith, A. B. (2012). Plated Cambrian bilaterians reveal the earliest stages of echinoderm evolution. PLoS ONE, 7(6), [e38296]. https://doi.org/10.1371/journal.pone.0038296 Publisher's PDF, also known as Version of record Link to published version (if available): 10.1371/journal.pone.0038296 Link to publication record in Explore Bristol Research PDF-document University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Plated Cambrian Bilaterians Reveal the Earliest Stages of Echinoderm Evolution Samuel Zamora1, Imran A. Rahman2, Andrew B. Smith1* 1 Department of Palaeontology, The Natural History Museum, London, United Kingdom, 2 School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom Abstract Echinoderms are unique in being pentaradiate, having diverged from the ancestral bilaterian body plan more radically than any other animal phylum. This transformation arises during ontogeny, as echinoderm larvae are initially bilateral, then pass through an asymmetric phase, before giving rise to the pentaradiate adult. Many fossil echinoderms are radial and a few are asymmetric, but until now none have been described that show the original bilaterian stage in echinoderm evolution. Here we report new fossils from the early middle Cambrian of southern Europe that are the first echinoderms with a fully bilaterian body plan as adults. Morphologically they are intermediate between two of the most basal classes, the Ctenocystoidea and Cincta.
    [Show full text]
  • Reinterpretation of the Enigmatic Ordovician Genus Bolboporites (Echinodermata)
    Reinterpretation of the enigmatic Ordovician genus Bolboporites (Echinodermata). Emeric Gillet, Bertrand Lefebvre, Véronique Gardien, Emilie Steimetz, Christophe Durlet, Frédéric Marin To cite this version: Emeric Gillet, Bertrand Lefebvre, Véronique Gardien, Emilie Steimetz, Christophe Durlet, et al.. Reinterpretation of the enigmatic Ordovician genus Bolboporites (Echinodermata).. Zoosymposia, Magnolia Press, 2019, 15 (1), pp.44-70. 10.11646/zoosymposia.15.1.7. hal-02333918 HAL Id: hal-02333918 https://hal.archives-ouvertes.fr/hal-02333918 Submitted on 13 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Reinterpretation of the Enigmatic Ordovician Genus Bolboporites 2 (Echinodermata) 3 4 EMERIC GILLET1, BERTRAND LEFEBVRE1,3, VERONIQUE GARDIEN1, EMILIE 5 STEIMETZ2, CHRISTOPHE DURLET2 & FREDERIC MARIN2 6 7 1 Université de Lyon, UCBL, ENSL, CNRS, UMR 5276 LGL-TPE, 2 rue Raphaël Dubois, F- 8 69622 Villeurbanne, France 9 2 Université de Bourgogne - Franche Comté, CNRS, UMR 6282 Biogéosciences, 6 boulevard 10 Gabriel, F-2100 Dijon, France 11 3 Corresponding author, E-mail: [email protected] 12 13 Abstract 14 Bolboporites is an enigmatic Ordovician cone-shaped fossil, the precise nature and systematic affinities of 15 which have been controversial over almost two centuries.
    [Show full text]
  • First Record of the Colonial Ascidian Didemnum Vexillum Kott, 2002 in the Mediterranean: Lagoon of Venice (Italy)
    BioInvasions Records (2012) Volume 1, Issue 4: 247–254 Open Access doi: http://dx.doi.org/10.3391/bir.2012.1.4.02 © 2012 The Author(s). Journal compilation © 2012 REABIC Research Article First record of the colonial ascidian Didemnum vexillum Kott, 2002 in the Mediterranean: Lagoon of Venice (Italy) Davide Tagliapietra1*, Erica Keppel1, Marco Sigovini1 and Gretchen Lambert2 1 CNR - National Research Council of Italy, ISMAR - Marine Sciences Institute, Arsenale - Tesa 104, Castello 2737/F, I-30122 Venice, Italy 2 University of Washington Friday Harbor Laboratories, Friday Harbor, WA 98250. Mailing address: 12001 11th Ave. NW, Seattle, WA 98177, USA E-mail: [email protected] (DT), [email protected] (EK), [email protected] (MS), [email protected] (GL) *Corresponding author Received: 30 July 2012 / Accepted: 16 October 2012 / Published online: 23 October 2012 Abstract Numerous colonies of the invasive colonial ascidian Didemnum vexillum Kott, 2002 have been found in the Lagoon of Venice (Italy) in 2012, overgrowing fouling organisms on maritime structures such as docks, pilings, and pontoons. This is the first record for the Mediterranean Sea. A survey conducted in July 2012 revealed that D. vexillum is present in the euhaline and tidally well flushed zones of the lagoon, whereas it was absent at the examined estuarine tracts and at the zones surrounding the saltmarshes. Suitable climatic, physiographic and saline features together with a high volume of international maritime traffic make the Lagoon of Venice a perfect hub for the successful introduction of temperate non-native species. Key words: Didemnum vexillum, Mediterranean, Lagoon of Venice, ascidian, fouling, marinas, invasive species Introduction cold coasts of North America and Europe as well as from Japan where it is probably native Didemnum vexillum Kott, 2002 (Ascidiacea: (Bullard et al.
    [Show full text]
  • Reply to €˜Re-Evaluating the Phylogenetic Position
    MATTERS ARISING https://doi.org/10.1038/s41467-020-14922-9 OPEN Reply to ‘Re-evaluating the phylogenetic position of the enigmatic early Cambrian deuterostome Yanjiahella’ ✉ Timothy P. Topper1,2 , Junfeng Guo3, Sébastien Clausen 4, Christian B. Skovsted2 & Zhifei Zhang 1 REPLYING TO Zamora, et al. Nature Communications https://doi.org/10.1038/s41467-020-14920-x (2020) ecently we documented a bilaterally symmetrical, solitary not detectable using light photography and SEM, as predicted. The 2 1234567890():,; organism, Yanjiahella biscarpa from the early Cambrian statement from Zamora et al. that latex casting could have R 1 (Fortunian) of China . We interpreted that Y. biscarpa resolved many of the uncertainties surrounding the composition, possessed an echinoderm-like plated theca, a muscular stalk shape and arrangement of the plates and the morphology of the similar to hemichordates and a pair of long, feeding appendages. stalk is an overstatement and ambitiously delivered without direct Our interpretation and our phylogenetic analysis suggest that examination of the fossil specimens. Y. biscarpa is a stem-echinoderm, which would confirm that The stereom microstructure of Cambrian echinoderms is poorly echinoderms acquired plates before pentaradial symmetry and known5, as the majority of specimens are preserved as moulds, or that their history is firmly rooted in bilateral forms. Zamora et al.2 recrystallized skeletons and the primary three-dimensional mor- however, have criticized our interpretation, arguing against an phology of their stereom has been obscured4–6. Generally, only echinoderm affinity, instead suggesting that the phylogenetic superficial pitting is preserved and it is this pitting that is inter- placement of Y.
    [Show full text]
  • Filogranula Cincta (Goldfuss, 1831), a Serpulid Worm (Polychaeta, Sedentaria, Serpulidae) from the Bohemian Cretaceous Basin
    SBORNÍK NÁRODNÍHO MUZEA V PRAZE ACTA MUSEI NATIONALIS PRAGAE Řada B – Přírodní vědy • sv. 71 • 2015 • čís. 3–4 • s. 293–300 Series B – Historia Naturalis • vol. 71 • 2015 • no. 3–4 • pp. 293–300 FILOGRANULA CINCTA (GOLDFUSS, 1831), A SERPULID WORM (POLYCHAETA, SEDENTARIA, SERPULIDAE) FROM THE BOHEMIAN CRETACEOUS BASIN TOMÁŠ KOČÍ Department of Palaeontology, Natural History Museum, National Museum, Václavské náměstí 68, 115 79 Praha 1, the Czech Republic; Ivančická 581, Praha 9 – Letňany 199 00, the Czech Republic; e-mail: [email protected] MANFRED JÄGER Lindenstrasse 53, D-72348 Rosenfeld, Germany; e-mail: [email protected] Kočí, T., Jäger, M. (2015): Filogranula cincta (GOLDFUSS, 1831), a serpulid worm (Polychaeta, Sedentaria, Serpulidae) from the Bohemian Cretaceous Basin. – Acta Mus. Nat. Pragae, Ser. B Hist. Nat., 71(3-4): 293–300, Praha. ISSN 1804-6479. Abstract. Tubes of the serpulid worm Filogranula cincta (GOLDFUSS, 1831) were found in several rocky coast facies and other nearshore / shallow water localities in the Bohemian Cretaceous Basin ranging in geological age from the Late Cenomanian to the Late Turonian. A mor - phological description, discussion regarding systematics and taxonomy and notes on palaeoecology and stratigraphy are presented. ■ Late Cretaceous, Polychaeta, Filogranula, Serpulidae, Palaeoecology Received April 24, 2015 Issued December, 2015 Introduction any Filogranula cincta specimen. It seems that, apart from the vague mention from Strehlen by Wegner (1913), for more Filogranula cincta (GOLDFUSS, 1831) is a small and than a hundred years no additional finds of Filogranula inconspicuous but nevertheless common serpulid species in cincta from the BCB had been published until the present the Bohemian Cretaceous Basin (BCB).
    [Show full text]
  • Plated Cambrian Bilaterians Reveal the Earliest Stages of Echinoderm Evolution
    Zamora, S., Rahman, I. A., & Smith, A. B. (2012). Plated Cambrian bilaterians reveal the earliest stages of echinoderm evolution. PLoS ONE, 7(6), [e38296]. https://doi.org/10.1371/journal.pone.0038296 Publisher's PDF, also known as Version of record Link to published version (if available): 10.1371/journal.pone.0038296 Link to publication record in Explore Bristol Research PDF-document University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Plated Cambrian Bilaterians Reveal the Earliest Stages of Echinoderm Evolution Samuel Zamora1, Imran A. Rahman2, Andrew B. Smith1* 1 Department of Palaeontology, The Natural History Museum, London, United Kingdom, 2 School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom Abstract Echinoderms are unique in being pentaradiate, having diverged from the ancestral bilaterian body plan more radically than any other animal phylum. This transformation arises during ontogeny, as echinoderm larvae are initially bilateral, then pass through an asymmetric phase, before giving rise to the pentaradiate adult. Many fossil echinoderms are radial and a few are asymmetric, but until now none have been described that show the original bilaterian stage in echinoderm evolution. Here we report new fossils from the early middle Cambrian of southern Europe that are the first echinoderms with a fully bilaterian body plan as adults. Morphologically they are intermediate between two of the most basal classes, the Ctenocystoidea and Cincta.
    [Show full text]
  • An Annotated Checklist of the Marine Macroinvertebrates of Alaska David T
    NOAA Professional Paper NMFS 19 An annotated checklist of the marine macroinvertebrates of Alaska David T. Drumm • Katherine P. Maslenikov Robert Van Syoc • James W. Orr • Robert R. Lauth Duane E. Stevenson • Theodore W. Pietsch November 2016 U.S. Department of Commerce NOAA Professional Penny Pritzker Secretary of Commerce National Oceanic Papers NMFS and Atmospheric Administration Kathryn D. Sullivan Scientific Editor* Administrator Richard Langton National Marine National Marine Fisheries Service Fisheries Service Northeast Fisheries Science Center Maine Field Station Eileen Sobeck 17 Godfrey Drive, Suite 1 Assistant Administrator Orono, Maine 04473 for Fisheries Associate Editor Kathryn Dennis National Marine Fisheries Service Office of Science and Technology Economics and Social Analysis Division 1845 Wasp Blvd., Bldg. 178 Honolulu, Hawaii 96818 Managing Editor Shelley Arenas National Marine Fisheries Service Scientific Publications Office 7600 Sand Point Way NE Seattle, Washington 98115 Editorial Committee Ann C. Matarese National Marine Fisheries Service James W. Orr National Marine Fisheries Service The NOAA Professional Paper NMFS (ISSN 1931-4590) series is pub- lished by the Scientific Publications Of- *Bruce Mundy (PIFSC) was Scientific Editor during the fice, National Marine Fisheries Service, scientific editing and preparation of this report. NOAA, 7600 Sand Point Way NE, Seattle, WA 98115. The Secretary of Commerce has The NOAA Professional Paper NMFS series carries peer-reviewed, lengthy original determined that the publication of research reports, taxonomic keys, species synopses, flora and fauna studies, and data- this series is necessary in the transac- intensive reports on investigations in fishery science, engineering, and economics. tion of the public business required by law of this Department.
    [Show full text]
  • Paleontological Contributions
    THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS July 14, 1988 Paper 120 HOMALOZOAN ECHINODERMS OF THE WHEELER FORMATION (MIDDLE CAMBRIAN) OF WESTERN UTAH' Georges Ubaghs and R. A. Robison Laboratoire de Paléontologie Animale, Université de Liége, B-4000, Liége, Belgium Department of Geology, The University of Kansas, Lawrence, Kansas 66045 Abstract. —Three new species, representing three of the four homalozoan classes, are described from the upper Wheeler Formation of middle Middle Cambrian age in west- central Utah. Ctenocystis colodon n. sp. is only the fifth species of Ctenocystoidea to be described. The new order Ctenocystida is defined. The solutan Castericystis? sprinklei n. sp. is the fifth species of Homoiostelea to be reported from Cambrian strata. The cornute Cothurnocystis? bifida n. sp. is the fifth species of Stylophora to be reported from Middle Cambrian strata worldwide and only the second from North America. This homalozoan fauna is among the most diverse known from any Cambrian formation. AMONG ECHINODERMS, homalozoans are un House Range, and the stylophoran Cothur- usual in their complete lack of radial symmetry. nocystis? bifida from the House Range. Representatives are relatively rare, especially in Each homalozoan species in the Wheeler Cambrian strata. Three new Cambrian spe- Formation is from a different locality. Such low cies, which represent three of the four homa- diversity is typical of most Cambrian echi- lozoan classes, are described here. All are noderm faunas, although locally each species from the upper Wheeler Formation of west- may be represented by numerous individuals. central Utah and include the ctenocystoid For several years, knowledge of the class Ctenocystis colodon from the Drum Mountains, Ctenocystoidea was limited to the single species the homoiostelean Castericystis? sprinklei from the Ctenocystis utahensis Robison and Sprinkle, 1969, which is locally abundant in the Spence Shale of Manuscript received 15 November 1987.
    [Show full text]
  • A Stem Group Echinoderm from the Basal Cambrian of China and the Origins of Ambulacraria
    ARTICLE https://doi.org/10.1038/s41467-019-09059-3 OPEN A stem group echinoderm from the basal Cambrian of China and the origins of Ambulacraria Timothy P. Topper 1,2,3, Junfeng Guo4, Sébastien Clausen 5, Christian B. Skovsted2 & Zhifei Zhang1 Deuterostomes are a morphologically disparate clade, encompassing the chordates (including vertebrates), the hemichordates (the vermiform enteropneusts and the colonial tube-dwelling pterobranchs) and the echinoderms (including starfish). Although deuter- 1234567890():,; ostomes are considered monophyletic, the inter-relationships between the three clades remain highly contentious. Here we report, Yanjiahella biscarpa, a bilaterally symmetrical, solitary metazoan from the early Cambrian (Fortunian) of China with a characteristic echinoderm-like plated theca, a muscular stalk reminiscent of the hemichordates and a pair of feeding appendages. Our phylogenetic analysis indicates that Y. biscarpa is a stem- echinoderm and not only is this species the oldest and most basal echinoderm, but it also predates all known hemichordates, and is among the earliest deuterostomes. This taxon confirms that echinoderms acquired plating before pentaradial symmetry and that their history is rooted in bilateral forms. Yanjiahella biscarpa shares morphological similarities with both enteropneusts and echinoderms, indicating that the enteropneust body plan is ancestral within hemichordates. 1 Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, 710069 Xi’an, China. 2 Department of Palaeobiology, Swedish Museum of Natural History, Box 50007104 05, Stockholm, Sweden. 3 Department of Earth Sciences, Durham University, Durham DH1 3LE, UK. 4 School of Earth Science and Resources, Key Laboratory for the study of Focused Magmatism and Giant Ore Deposits, MLR, Chang’an University, 710054 Xi’an, China.
    [Show full text]
  • The Early History of the Metazoa—A Paleontologist's Viewpoint
    ISSN 20790864, Biology Bulletin Reviews, 2015, Vol. 5, No. 5, pp. 415–461. © Pleiades Publishing, Ltd., 2015. Original Russian Text © A.Yu. Zhuravlev, 2014, published in Zhurnal Obshchei Biologii, 2014, Vol. 75, No. 6, pp. 411–465. The Early History of the Metazoa—a Paleontologist’s Viewpoint A. Yu. Zhuravlev Geological Institute, Russian Academy of Sciences, per. Pyzhevsky 7, Moscow, 7119017 Russia email: [email protected] Received January 21, 2014 Abstract—Successful molecular biology, which led to the revision of fundamental views on the relationships and evolutionary pathways of major groups (“phyla”) of multicellular animals, has been much more appre ciated by paleontologists than by zoologists. This is not surprising, because it is the fossil record that provides evidence for the hypotheses of molecular biology. The fossil record suggests that the different “phyla” now united in the Ecdysozoa, which comprises arthropods, onychophorans, tardigrades, priapulids, and nemato morphs, include a number of transitional forms that became extinct in the early Palaeozoic. The morphology of these organisms agrees entirely with that of the hypothetical ancestral forms reconstructed based on onto genetic studies. No intermediates, even tentative ones, between arthropods and annelids are found in the fos sil record. The study of the earliest Deuterostomia, the only branch of the Bilateria agreed on by all biological disciplines, gives insight into their early evolutionary history, suggesting the existence of motile bilaterally symmetrical forms at the dawn of chordates, hemichordates, and echinoderms. Interpretation of the early history of the Lophotrochozoa is even more difficult because, in contrast to other bilaterians, their oldest fos sils are preserved only as mineralized skeletons.
    [Show full text]
  • Species Diversity in the Antrodia Crassa Group (Polyporales, Basidiomycota)
    fungal biology 119 (2015) 1291e1310 journal homepage: www.elsevier.com/locate/funbio Species diversity in the Antrodia crassa group (Polyporales, Basidiomycota) a b, c a Viacheslav SPIRIN , Kadri RUNNEL *, Josef VLASAK , Otto MIETTINEN , ~ Kadri POLDMAAb aBotanical Unit (Mycology), Finnish Museum of Natural History, University of Helsinki, Unioninkatu 44, 00170 Helsinki, Finland bDepartment of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, EE-51015 Tartu, Estonia cBiology Centre of the Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic article info abstract Article history: Antrodia is a polyphyletic genus, comprising brown-rot polypores with annual or short- Received 18 July 2015 lived perennial resupinate, dimitic basidiocarps. Here we focus on species that are Received in revised form closely related to Antrodia crassa, and investigate their phylogeny and species delimita- 6 September 2015 tion using geographic, ecological, morphological and molecular data (ITS and LSU Accepted 25 September 2015 rDNA, tef1). Phylogenetic analyses distinguished four clades within the monophyletic Available online 9 October 2015 group of eleven conifer-inhabiting species (five described herein): (1)A. crassa s. str. (bo- Corresponding Editor: real Eurasia), Antrodia cincta sp. nova (North America) and Antrodia cretacea sp. nova (hol- Martin I. Bidartondo arctic), all three being characterized by inamyloid skeletal hyphae that dissolve quickly in KOH solution; (2) Antrodia ignobilis sp. nova, Antrodia sitchensis and Antrodia sordida Keywords: from North America, and Antrodia piceata sp. nova (previously considered conspecific Host specificity with A. sitchensis) from Eurasia, possessing amyloid skeletal hyphae; (3) Antrodia ladiana Internal transcribed spacer sp.
    [Show full text]
  • Checklist of the Bees in the Czech Republic and Slovakia with Comments on Their Distribution and Taxonomy (Insecta: Hymenoptera: Apoidea)
    ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS SBORNÍK MENDELOVY ZEMĚDĚLSKÉ A LESNICKÉ UNIVERZITY V BRNĚ Ročník LII 4 Číslo 1, 2004 CHECKLIST OF THE BEES IN THE CZECH REPUBLIC AND slovakia WITH COMMENTS ON THEIR DISTRIBUTION AND taxonomy (Insecta: Hymenoptera: Apoidea) A. Přidal Received: September 5, 2003 Abstract PŘIDAL, A.: Checklist of the bees in the Czech Republic and Slovakia with comments on their distribu- tion and taxonomy (insecta: Hymenoptera: Apoidea). Acta univ. agric. et silvic. Mendel. Brun., 2004, LII, No. 1, pp. 29-66 Complete faunistics was compiled in countries surrounding the Czech Republic and Slovakia. The latest checklist of the bee fauna from the then Czechoslovakia being published well over a decade ago, the aim of this paper is to up-date Kocourek’s checklist (hereinafter referred to as only ”the List”) from 1989. In the present paper, inaccuracies occurring in Kocourek’s checklist (e.g. using of junior synonyms or homonyms, spelling of names, incorrect species distribution, etc.) are corrected. In addition, new records according to literature data, findings communicated by colleagues, or own records, are sum- marised. The compilation of this faunistic list required checking of over 750 names of the species group and more than 140 supraspecific names to be used valid and available names. The faunistic revision results in the following findings. In total, 431 bee species range the Bohemian territory (occurrence was approved); of that, the follow- ing species are newly included: 4 species according to records (captured or checked specimen(s)) and 3 species as per literature data. Five species are conditionally removed from the Bohemian fauna, ten species are missing, eleven species are removed from the checklist, and the occurrence of one species is potential.
    [Show full text]