Some Late Cambrian Molluscs from Liaoning Province, China
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Review of the Geology and Paleontology of the Ellsworth Mountains, Antarctica
U.S. Geological Survey and The National Academies; USGS OF-2007-1047, Short Research Paper 107; doi:10.3133/of2007-1047.srp107 Review of the geology and paleontology of the Ellsworth Mountains, Antarctica G.F. Webers¹ and J.F. Splettstoesser² ¹Department of Geology, Macalester College, St. Paul, MN 55108, USA ([email protected]) ²P.O. Box 515, Waconia, MN 55387, USA ([email protected]) Abstract The geology of the Ellsworth Mountains has become known in detail only within the past 40-45 years, and the wealth of paleontologic information within the past 25 years. The mountains are an anomaly, structurally speaking, occurring at right angles to the Transantarctic Mountains, implying a crustal plate rotation to reach the present location. Paleontologic affinities with other parts of Gondwanaland are evident, with nearly 150 fossil species ranging in age from Early Cambrian to Permian, with the majority from the Heritage Range. Trilobites and mollusks comprise most of the fauna discovered and identified, including many new genera and species. A Glossopteris flora of Permian age provides a comparison with other Gondwana floras of similar age. The quartzitic rocks that form much of the Sentinel Range have been sculpted by glacial erosion into spectacular alpine topography, resulting in eight of the highest peaks in Antarctica. Citation: Webers, G.F., and J.F. Splettstoesser (2007), Review of the geology and paleontology of the Ellsworth Mountains, Antarctica, in Antarctica: A Keystone in a Changing World – Online Proceedings of the 10th ISAES, edited by A.K. Cooper and C.R. Raymond et al., USGS Open- File Report 2007-1047, Short Research Paper 107, 5 p.; doi:10.3133/of2007-1047.srp107 Introduction The Ellsworth Mountains are located in West Antarctica (Figure 1) with dimensions of approximately 350 km long and 80 km wide. -
Monoplacophoran Limpet
16 McLean: Monoplacophoran Limpet FIGURES 17-21. Neopilinid radular ribbons, magnifications adjusted to show a similar number of teeth rows. FIGURE 17, Vema (Vema) ewingi. intact ribbon with teeth aligned (LACM 65-11, 6200 m. 110 mi. W of Callao. Pern. R/V ANTON BRUUN, 24 November 1965). FIGURE 18, Vema (Vema) ewingi. another portion of same ribbon with lateral teeth turned to the side. FIGURE 19. Neopilina veleronis. intact ribbon of paratype, teeth not aligned (AHF 603, 2730-2769 m, 30 mi. W of Natividad Island. Baja California, Mexico). FIGURE 20, Vema (Laevipilina) hyalina new species, intact ribbon with teeth aligned, focused on shafts of lateral teeth (LACM 19148). FIGURE 21, Vema (Laevipilina) hyalina, same ribbon, focused on fringe of first marginal teeth. instead of the highly reduced condition in these two species. Al- small-sized species have similar teeth. Radular differences among though the first lateral of N. veleronis is somewhat larger than it the species examined are quantitative rather than qualitative, sup- is in the other two species, that of V. hyalina is still the larger. porting placement of the four species in the same family. A study The fringed first marginal of V. hyalina is much broader than in of the radulae of the other three living species of neopilinids N. veleronis. Only in V. hyalina is the fringed tooth so broad that should reveal further specific differences. it overlaps the opposite member in the central part of the ribbon. The radula of neopilinid monoplacophorans is very similar to The second and third laterals of V. -
Morphology and Systematic Position of Tryhlidium Canadense Whiteaves
Morphology and systematic position of Tryblidium canadense Whiteaves, 1884 (Mollusca) from the Silurian of North America JOHNS. PEEL Peel, J. S.: Morphology and systematic position of Tryblidium Canadense Whiteaves, 1884 (Mollusca) from the Silurian of North America. Bull. geol. Soc. Denmark, vol. 38, pp. 43-51. Copenhagen, April 25th, 1990. https://doi.org/10.37570/bgsd-1990-38-04 The nomenclative history of Tryblidium canadense Whiteaves, 1884, a large, oval, univalved mollusc originally described from the Silurian Guelph Formation of Ontario, is reviewed. Following comparison to Archinace/la Ulrich & Scofield, 1897, in which genus it has generally been placed for almost a century, Whiteaves' species is redescribed and assigned to a new gastropod genus, Guelphinace/la. John S. Peel, Geological Survey of Greenland, Oster Voldgade JO, 1350 Copenhagen K, Denmark. February 10th, 1989. Whiteaves (1884) described a single internal the sub-apical wall. He commented that the mould of a large (45 mm), oval, univalved mol structure seemed to be a single continuous mus lusc from the Guelph Formation (Silurian) of cular impression and not two separate depres Hespeler, Ontario, Canada as Tryblidium Cana sions, as suggested by Lindstrom (1884), al dense (Fig. 1). Uncertainty surrounding its sys though he did not refer directly to the latter's tematic position developed immediately when description. He made no reference to the thin Lindstrom (1884) questioned the assignment to dorsal band which Lindstrom (1884) had consid the genus Tryblidium -
Shell Microstructures in Early Cambrian Molluscs
Shell microstructures in Early Cambrian molluscs ARTEM KOUCHINSKY Kouchinsky, A. 2000. Shell microstructures in Early Cambrian molluscs. - Acta Palaeontologica Polonica 45,2, 119-150. The affinities of a considerable part of the earliest skeletal fossils are problematical, but investigation of their microstructures may be useful for understanding biomineralization mechanisms in early metazoans and helpful for their taxonomy. The skeletons of Early Cambrian mollusc-like organisms increased by marginal secretion of new growth lamel- lae or sclerites, the recognized basal elements of which were fibers of apparently aragon- ite. The juvenile part of some composite shells consisted of needle-like sclerites; the adult part was built of hollow leaf-like sclerites. A layer of mineralized prism-like units (low aragonitic prisms or flattened spherulites) surrounded by an organic matrix possibly existed in most of the shells with continuous walls. The distribution of initial points of the prism-like units on a periostracurn-like sheet and their growth rate were mostly regular. The units may be replicated on the surface of internal molds as shallow concave poly- gons, which may contain a more or less well-expressed tubercle in their center. Tubercles are often not enclosed in concave polygons and may co-occur with other types of tex- tures. Convex polygons seem to have resulted from decalcification of prism-like units. They do not co-occur with tubercles. The latter are interpreted as casts of pore channels in the wall possibly playing a role in biomineralization or pits serving as attachment sites of groups of mantle cells. Casts of fibers and/or lamellar units may overlap a polygonal tex- ture or occur without it. -
A Molecular Phylogeny of the Patellogastropoda (Mollusca: Gastropoda)
^03 Marine Biology (2000) 137: 183-194 ® Spnnger-Verlag 2000 M. G. Harasevvych A. G. McArthur A molecular phylogeny of the Patellogastropoda (Mollusca: Gastropoda) Received: 5 February 1999 /Accepted: 16 May 2000 Abstract Phylogenetic analyses of partiaJ J8S rDNA formia" than between the Patellogastropoda and sequences from species representing all living families of Orthogastropoda. Partial 18S sequences support the the order Patellogastropoda, most other major gastro- inclusion of the family Neolepetopsidae within the su- pod groups (Cocculiniformia, Neritopsma, Vetigastro- perfamily Acmaeoidea, and refute its previously hy- poda, Caenogastropoda, Heterobranchia, but not pothesized position as sister group to the remaining Neomphalina), and two additional classes of the phylum living Patellogastropoda. This region of the Í8S rDNA Mollusca (Cephalopoda, Polyplacophora) confirm that gene diverges at widely differing rates, spanning an order Patellogastropoda comprises a robust clade with high of magnitude among patellogastropod lineages, and statistical support. The sequences are characterized by therefore does not provide meaningful resolution of the the presence of several insertions and deletions that are relationships among higher taxa of patellogastropods. unique to, and ubiquitous among, patellogastropods. Data from one or more genes that evolve more uni- However, this portion of the 18S gene is insufficiently formly and more rapidly than the ISSrDNA gene informative to provide robust support for the mono- (possibly one or more -
Bulletin of the Geological Society of Denmark
Muscle scars in For cellia (Gastropoda; Pleurotomariacea) from the Carboniferous of England JOHN S. PEEL Peel, J. S.: Muscle scars in Porcellia (Gastropoda; Pleurotomariacea) from the Carboniferous of England. DGF Bull. geol. Soc. Denmark, vol. 35, pp. 53-58, Copenhagen, October, 29th, 1986 Two shell retractor muscles are described on an internal mould of Porcellia woodwardi, a pleurotomaria- cean gastropod from the Carboniferous of England. The scars are located at the junction between the um bilical wall, and the apical surface and the basal surface, respectively. Similar positioning of muscle scars in Bellerophon of the same age reflects morphological convergence of the planispiral, anisostrophic Por cellia with the planispiral, but isostrophic Bellerophon. It is concluded that the shape of muscle scars, in detail, can not contribute to solving the question of the systematic position of Bellerophon. John S. Peel, Grønlands Geologiske Undersøgelse, Øster Voldgade 10. DK-1350 København K, Denmark, January 8th, 1986. The bellerophontiform molluscs are a complex of its single pair of circumbilical muscles and the more than fifty isostrophically coiled genera of single pair of shell-attachment muscles of some uncertain systematic position. While traditionally extant, slit-bearing pleurotomariaceans. Other considered to be gastropods, an extended debate bellerophontiform molluscs have been conside exists in the literature as to whether or not this red to be monoplacophorans after comparison position should be maintained, or if the group between their multiple pairs of muscle scars and should be transferred in part, or as an entity, to the discrete pairs of muscle scars in the living the Monoplacophora. The central theme in this monoplacophoran Neopilina Lemche 1957, or its debate concerns the presence or absence of tor immediate, but ancient relatives Pilina Koken sion. -
Keeping a Lid on It: Muscle Scars and the Mystery of the Mobergellidae
1 Keeping a lid on it: muscle scars and the mystery of the 2 Mobergellidae 3 4 TIMOTHY P. TOPPER1,2* and CHRISTIAN B. SKOVSTED1 5 6 1Department of Palaeobiology, Swedish Museum of Natural History, P.O. Box 50007, 7 SE-104 05, Stockholm, Sweden. 8 2Palaeoecosystems Group, Department of Earth Sciences, Durham University, Durham 9 DH1 3LE, UK. 10 11 Mobergellans were one of the first Cambrian skeletal groups to be recognized yet have 12 long remained one of the most problematic in terms of biological function and affinity. 13 Typified by a disc-shaped, phosphatic sclerite the most distinctive character of the 14 group is a prominent set of internal scars, interpreted as representing sites of former 15 muscle attachment. Predominantly based on muscle scar distribution, mobergellans 16 have been compared to brachiopods, bivalves and monoplacophorans, however a 17 recurring theory that the sclerites acted as operculum remains untested. Rather than 18 correlate the number of muscle scars between taxa, here we focus on the percentage of 19 the inner surface shell area that the scars constitute. We investigate two mobergellan 20 species, Mobergella holsti and Discinella micans comparing the Cambrian taxa with the 21 muscle scars of a variety of extant and fossil marine invertebrate taxa to test if the 22 mobergellan muscle attachment area is compatible with an interpretation as operculum. 23 The only skeletal elements in our study with a comparable muscle attachment 24 percentage are gastropod opercula. Complemented with additional morphological 25 information, our analysis supports the theory that mobergellan sclerites acted as an 26 operculum presumably from a tube-living organism. -
Mem170-Bm.Pdf by Guest on 30 September 2021 452 Index
Index [Italic page numbers indicate major references] acacamite, 437 anticlines, 21, 385 Bathyholcus sp., 135, 136, 137, 150 Acanthagnostus, 108 anticlinorium, 33, 377, 385, 396 Bathyuriscus, 113 accretion, 371 Antispira, 201 manchuriensis, 110 Acmarhachis sp., 133 apatite, 74, 298 Battus sp., 105, 107 Acrotretidae, 252 Aphelaspidinae, 140, 142 Bavaria, 72 actinolite, 13, 298, 299, 335, 336, 339, aphelaspidinids, 130 Beacon Supergroup, 33 346 Aphelaspis sp., 128, 130, 131, 132, Beardmore Glacier, 429 Actinopteris bengalensis, 288 140, 141, 142, 144, 145, 155, 168 beaverite, 440 Africa, southern, 52, 63, 72, 77, 402 Apoptopegma, 206, 207 bedrock, 4, 58, 296, 412, 416, 422, aggregates, 12, 342 craddocki sp., 185, 186, 206, 207, 429, 434, 440 Agnostidae, 104, 105, 109, 116, 122, 208, 210, 244 Bellingsella, 255 131, 132, 133 Appalachian Basin, 71 Bergeronites sp., 112 Angostinae, 130 Appalachian Province, 276 Bicyathus, 281 Agnostoidea, 105 Appalachian metamorphic belt, 343 Billingsella sp., 255, 256, 264 Agnostus, 131 aragonite, 438 Billingsia saratogensis, 201 cyclopyge, 133 Arberiella, 288 Bingham Peak, 86, 129, 185, 190, 194, e genus, 105 Archaeocyathidae, 5, 14, 86, 89, 104, 195, 204, 205, 244 nudus marginata, 105 128, 249, 257, 281 biogeography, 275 parvifrons, 106 Archaeocyathinae, 258 biomicrite, 13, 18 pisiformis, 131, 141 Archaeocyathus, 279, 280, 281, 283 biosparite, 18, 86 pisiformis obesus, 131 Archaeogastropoda, 199 biostratigraphy, 130, 275 punctuosus, 107 Archaeopharetra sp., 281 biotite, 14, 74, 300, 347 repandus, 108 Archaeophialia, -
Ordovician News 2005
ORDOVICIAN NEWS SUBCOMMISSION ON ORDOVICIAN STRATIGRAPHY INTERNATIONAL COMMISSION ON STRATIGRAPHY Nº 22 2005 ORDOVICIAN NEWS Nº 22 INTERNATIONAL UNION OF GEOLOGIAL SCIENCES President: ZHANG HONGREN (China) Vice-President: S. HALDORSEN (Norway) Secretary General: P. T. BOBROWSKI (Canada) Treasurer: A. BRAMBATI (Italy) Past-President: E.F.J. DE MULDER (The Netherlands) INTERNATIONAL COMMISSION ON STRATIGRAPHY Chairman: F. GRADSTEIN (Norway) Vice-Chairman: S. C. FINNEY (USA) Secretary General: J. OGG (USA) Past-Chairman: J. REMANE (Switzerland) INTERNATIONAL SUBCOMMISSION ON ORDOVICIAN STRATIGRAPHY Chairman: CHEN XU (China) Vice-Chairman: J. C. GUTIÉRREZ MARCO (Spain) Secretary: G. L. ALBANESI (Argentina) F. G. ACEÑOLAZA (Argentina) A. V. DRONOV (Russia) O. FATKA (Czech Republic) S. C. FINNEY (USA) R. A. FORTEY (UK) D. A. HARPER (Denmark) W. D. HUFF (USA) LI JUN (China) C. E. MITCHELL (USA) R. S. NICOLL (Australia) G. S. NOWLAN (Canada) A. W. OWEN (UK) F. PARIS (France) I. PERCIVAL (Australia) L. E. POPOV (Russia) M. R. SALTZMAN (USA) Copyright © IUGS 2005 i ORDOVICIAN NEWS Nº 22 CONTENTS Page NOTE FOR CONTRIBUTORS iii EDITOR'S NOTE iii CHAIRMAN´S AND SECRETARY´S ADDRESSES iii CHAIRMAN´S REPORT 1 SOS ANNUAL REPORT FOR 2001 1 INTERNATIONAL SYMPOSIA AND CONFERENCES 4 PROJECTS 7 SCIENTIFIC REPORTS 7 HONORARY NOTES 8 MISCELLANEA 9 CURRENT RESEARCH 9 RECENT ORDOVICIAN PUBLICATIONS 25 NAMES AND ADDRESS CHANGES 40 URL: http://www.ordovician.cn, http://seis.natsci.csulb.edu/ISOS Cover: The Wangjiawan GSSP for the base of the Hirnantian Stage, China. ii ORDOVICIAN NEWS Nº 22 NOTE FOR CONTRIBUTORS The continued health and survival of Ordovician News depends on YOU to send in items of Ordovician interest such as lists and reviews of recent publications, brief summaries of current research, notices of relevant local, national and international meetings, etc. -
Geology and Paleontology of the Ellsworth Mountains, Antarctica
should contact a Board member through the American Proposal forms, information for contributors, and catalogs of Geophysical Union to determine whether a volume in a specific books in print are available from the American Geophysical field is in process and whether the work is appropriate for Union, 2000 Florida Avenue, N.W., Washington, D.C. 20009. inclusion. The telephone number is (202) 462-6903. The bibliography is stored on a word processor disk at the Geology and paleontology of the Minnesota Geological Survey. A copy is available from the au- Ellsworth Mountains thors on request. The contents list of chapters is given below. Geology and Paleontology of the Ellsworth Mountains, Antarctica. G.F. Webers, C. Craddock, and J.F. Splettstoesser, Editors. Geological Society of America Memoir, no. 170. G.E. WEBERS • Webers, G. E, C. Craddock, and J.E Splettstoesser. History of exploration and geologic history of the Ellsworth Mountains. Macalester College • Webers, G.F., R.L. Bauer, J.M. Anderson, W. Buggisch, R.W. St. Paul, Minnesota 55105 Ojakangas, and K.B. Sporli. Geology of the Heritage Group of the Ellsworth Mountains. J.F. SPLETTSTOESSER • Sporli, K.B. The crashsite Group of the Ellsworth Mountains, West Antarctica. • Matsch, C.L., and R.W. Ojakangas. Stratigraphy and sedi- Minnesota Geological Survey mentology of the Whiteout Conglomerate—A late Paleozoic University of Minnesota St. Paul, Minnesota 55114 glacigenic sequence in the Ellsworth Mountains, West Antarctica. • Collinson, J.W., C.L. Vavra, and J.M. Zawiskie. Sedimen- tology of the Polarstar Formation, Permian, Ellsworth Moun- Coordination continued in 1987 on the production of a vol- tains, Antarctica. -
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. -
Geological Investigations and Logistics in the Ellsworth Mountains, 1979-80
900 difference in declination is due to rapid changes in the References paleomagnetic field with respect to Antarctica during the Lower Paleozoic cannot be discounted at the present level Alley, R. B., and Watts, D. R. 1979. Paleomagnetic investigation of of coverage. A solid data base from the Paleozoic of the east the northern antarctic peninsula. EQS. Transactions, American antarctic craton will be required before the problem is fully Geophysical Union, 60, 240. resolved. Furthermore, the results for the Ellsworth Moun- Dalziel, I. W. D. In press. The pre-Jurassic history of the Scotia Arc: tains presented here represent only 3 sites of the total of 70. A review and progress report. In C. Craddock (Ed.), Antarctic At this stage in the investigation, the data are most consis- Geoscience. Madison: The University of Wisconsin Press. deWit, M. J 1977. The evolution of the Scotia Arc as a key to the re- tent with a theory proposing a microplate nature of West . construction of southwestern Gondwanaland. Tectonophysics, 37, Antarctica. 53-82. Elliot, D. H., Watts, D. R., Alley, R. B., and Gracanin, T. M. 1978. Geo- logic studies in the northern antarctic peninsula, R/V Hero cruise 78-lB. February 1978. Antarctic Journal of the U.S., 13(4), 12-13. Elston, D. R., and Purucker, M. E. 1979. Detrital magnetization in 50 Sr ndon. red beds of the Moenkopi Formation (Triassic), Gray Mountain, C>. Arizona. Journal of Geophysical Research, 84, 1653-1666. EAST Graham, J. W. 1949. The stability and significance of magnetism in ANTARCT IC - CRATON sedimentary rocks. Journal of Geophysical Research, 59, 131 137.