Mollusca, Monoplacophora Plus Polyplacophora
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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. -
Biodiversity and Trophic Ecology of Hydrothermal Vent Fauna Associated with Tubeworm Assemblages on the Juan De Fuca Ridge
Biogeosciences, 15, 2629–2647, 2018 https://doi.org/10.5194/bg-15-2629-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Biodiversity and trophic ecology of hydrothermal vent fauna associated with tubeworm assemblages on the Juan de Fuca Ridge Yann Lelièvre1,2, Jozée Sarrazin1, Julien Marticorena1, Gauthier Schaal3, Thomas Day1, Pierre Legendre2, Stéphane Hourdez4,5, and Marjolaine Matabos1 1Ifremer, Centre de Bretagne, REM/EEP, Laboratoire Environnement Profond, 29280 Plouzané, France 2Département de sciences biologiques, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec, H3C 3J7, Canada 3Laboratoire des Sciences de l’Environnement Marin (LEMAR), UMR 6539 9 CNRS/UBO/IRD/Ifremer, BP 70, 29280, Plouzané, France 4Sorbonne Université, UMR7144, Station Biologique de Roscoff, 29680 Roscoff, France 5CNRS, UMR7144, Station Biologique de Roscoff, 29680 Roscoff, France Correspondence: Yann Lelièvre ([email protected]) Received: 3 October 2017 – Discussion started: 12 October 2017 Revised: 29 March 2018 – Accepted: 7 April 2018 – Published: 4 May 2018 Abstract. Hydrothermal vent sites along the Juan de Fuca community structuring. Vent food webs did not appear to be Ridge in the north-east Pacific host dense populations of organised through predator–prey relationships. For example, Ridgeia piscesae tubeworms that promote habitat hetero- although trophic structure complexity increased with ecolog- geneity and local diversity. A detailed description of the ical successional stages, showing a higher number of preda- biodiversity and community structure is needed to help un- tors in the last stages, the food web structure itself did not derstand the ecological processes that underlie the distribu- change across assemblages. -
Species Trophic Guild – Nutritional Mode Reference(S) Annelida Polychaeta Siboglinidae Ridgeia Piscesae Symbiotic Jones (1985)*; Southward Et Al
Species Trophic guild – nutritional mode Reference(s) Annelida Polychaeta Siboglinidae Ridgeia piscesae Symbiotic Jones (1985)*; Southward et al. (1995); Bergquist et al. (2007); this study Maldanidae Nicomache venticola Bacterivore – surface deposit feeder or grazer Blake and Hilbig (1990)*; Bergquist et al. (2007); this study Dorvilleidae Ophryotrocha globopalpata Predator Blake and Hilbig (1990)*; Bergquist et al. (2007); this study Orbiniidae Berkeleyia sp. nov. Scavenger/detritivore – suspension feeder Jumars et al. (2015); this study Hesionidae Hesiospina sp. nov.a Predator Bonifácio et al. (2018)*; this study Phyllodocidae Protomystides verenae Predator Blake and Hilbig (1990)*; Bergquist et al. (2007); this study Polynoidae Branchinotogluma tunnicliffeae Predator Pettibone (1988)*; Bergquist et al. (2007); this study Branchinotogluma sp. Predator – Lepidonotopodium piscesae Predator Pettibone (1988)*; Levesque et al. (2006); Bergquist et al. (2007); this study Levensteiniella kincaidi Predator Pettibone (1985)*; Bergquist et al. (2007); this study Sigalionidae Pholoe courtneyae Predator Blake (1995)*; Sweetman et al. (2013) Syllidae Sphaerosyllis ridgensis Predator Blake and Hilbig (1990)*; Bergquist et al. (2007); this study Alvinellidae Paralvinella dela Bacterivore – surface deposit feeder or grazer; suspension feeder Detinova (1988)*; this study Paralvinella palmiformis Bacterivore – surface deposit feeder or grazer; suspension feeder Desbruyères and Laubier (1986*, 1991); Levesque et al. (2003); this study Paralvinella pandorae Bacterivore – surface deposit feeder or grazer; suspension feeder Desbruyères and Laubier (1986*, 1991); Levesque et al. (2003); this study Paralvinella sulfincola Bacterivore – surface deposit feeder or grazer; suspension feeder Tunnicliffe et al. (1993)*; Levesque et al. (2003); this study Ampharetidae Amphisamytha carldarei Scavenger/detritivore – surface deposit feeder or grazer Stiller et al. (2013)*; McHugh and Tunnicliffe (1994); Bergquist et al. -
Zootaxa, the Youngest Rostroconch Mollusc from North America
Zootaxa 2603: 61–64 (2010) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Correspondence ZOOTAXA Copyright © 2010 · Magnolia Press ISSN 1175-5334 (online edition) The youngest rostroconch mollusc from North America, Minycardita capitanensis n. sp. MICHAEL J. VENDRASCO1, RICHARD D. HOARE2 & GORDEN L. BELL, JR3 1Department of Biological Science, California State University, Fullerton, Fullerton, CA 92834-6850, USA. E-mail: [email protected] 2Department of Geology, Bowling Green State University, Bowling Green, OH 43403, USA. E-mail: [email protected] 3Guadalupe Mountains National Park, 400 Pine Canyon Drive, Salt Flat, TX 79847, USA. E-mail: [email protected] Rostroconchs are an extinct class of mollusc that lived worldwide through most or all of the Paleozoic Era (Runnegar 1978). They were most diverse in the early Paleozoic (Pojeta 1985), perhaps due to a lower rate of evolution in the rostroconch clade that survived the end-Ordovician mass extinction event (Wagner 1997). Rostroconchs have a univalved larval shell and a pseudo-bivalved adult shell. Their ecology appears to have ranged from infaunal to rarely epifaunal, and from deposit to suspension feeding (Pojeta et al. 1972, Pojeta & Runnegar 1976, Runnegar 1978, Pojeta 1987). A single but well-preserved, essentially complete rostroconch specimen was recovered from the region surrounded by the famous Capitan Reef of the Permian of West Texas (Newell et al. 1953). In particular, the specimen is from the upper scaphopod bed of the Reef Trail Member of the Bell Canyon Formation exposed in the Guadalupe Mountains National Park (Rigby & Bell 2005: fig. 2). The fusulinid biostratigraphic zonal indicator Paraboultonia splendens Skinner & Wilde, 1954 occurs both below the upper scaphopod bed and above it, indicating that this horizon was deposited during the latest Guadalupian (late middle Permian) (Rigby & Bell 2006), and thus is the youngest known deposit in North America to contain a rostroconch. -
Reproduction of Gastropods from Vents on the East Pacific Rise and the Mid-Atlantic Ridge
JOBNAME: jsr 27#1 2008 PAGE: 1 OUTPUT: Friday March 14 03:55:15 2008 tsp/jsr/159953/27-1-19 View metadata, citation and similar papers at core.ac.uk brought to you by CORE Journal of Shellfish Research, Vol. 27, No. 1, 107–118, 2008. provided by Woods Hole Open Access Server REPRODUCTION OF GASTROPODS FROM VENTS ON THE EAST PACIFIC RISE AND THE MID-ATLANTIC RIDGE PAUL A. TYLER,1* SOPHIE PENDLEBURY,1 SUSAN W. MILLS,2 LAUREN MULLINEAUX,2 KEVIN J. ECKELBARGER,3 MARIA BAKER1 AND CRAIG M. YOUNG4 1National Oceanography Centre, Southampton, University of Southampton, Southampton SO14 3ZH, United Kingdom; 2Biology Department Woods Hole Oceanographic Institution, Woods Hole Massachusetts 02543; 3Darling Marine Center, University of Maine, 193 Clark’s Cove Road. Walpole, Maine 04573; 4Oregon Institute of Marine Biology, University of Oregon, Charleston, Oregon 97420 ABSTRACT The gametogenic biology is described for seven species of gastropod from hydrothermal vents in the East Pacific and from the Mid-Atlantic Ridge. Species of the limpet genus Lepetodrilus (Family Lepetodrilidae) had a maximum unfertilized oocyte size of <90 mm and there was no evidence of reproductive periodicity or spatial variation in reproductive pattern. Individuals showed early maturity with females undergoing gametogenesis at less than one third maximum body size. There was a power relationship between shell length and fecundity, with a maximum of ;1,800 oocytes being found in one individual, although individual fecundity was usually <1,000. Such an egg size might be indicative of planktotrophic larval development, but there was never any indication of shell growth in larvae from species in this genus. -
(Approx) Mixed Micro Shells (22G Bags) Philippines € 10,00 £8,64 $11,69 Each 22G Bag Provides Hours of Fun; Some Interesting Foraminifera Also Included
Special Price £ US$ Family Genus, species Country Quality Size Remarks w/o Photo Date added Category characteristic (€) (approx) (approx) Mixed micro shells (22g bags) Philippines € 10,00 £8,64 $11,69 Each 22g bag provides hours of fun; some interesting Foraminifera also included. 17/06/21 Mixed micro shells Ischnochitonidae Callistochiton pulchrior Panama F+++ 89mm € 1,80 £1,55 $2,10 21/12/16 Polyplacophora Ischnochitonidae Chaetopleura lurida Panama F+++ 2022mm € 3,00 £2,59 $3,51 Hairy girdles, beautifully preserved. Web 24/12/16 Polyplacophora Ischnochitonidae Ischnochiton textilis South Africa F+++ 30mm+ € 4,00 £3,45 $4,68 30/04/21 Polyplacophora Ischnochitonidae Ischnochiton textilis South Africa F+++ 27.9mm € 2,80 £2,42 $3,27 30/04/21 Polyplacophora Ischnochitonidae Stenoplax limaciformis Panama F+++ 16mm+ € 6,50 £5,61 $7,60 Uncommon. 24/12/16 Polyplacophora Chitonidae Acanthopleura gemmata Philippines F+++ 25mm+ € 2,50 £2,16 $2,92 Hairy margins, beautifully preserved. 04/08/17 Polyplacophora Chitonidae Acanthopleura gemmata Australia F+++ 25mm+ € 2,60 £2,25 $3,04 02/06/18 Polyplacophora Chitonidae Acanthopleura granulata Panama F+++ 41mm+ € 4,00 £3,45 $4,68 West Indian 'fuzzy' chiton. Web 24/12/16 Polyplacophora Chitonidae Acanthopleura granulata Panama F+++ 32mm+ € 3,00 £2,59 $3,51 West Indian 'fuzzy' chiton. 24/12/16 Polyplacophora Chitonidae Chiton tuberculatus Panama F+++ 44mm+ € 5,00 £4,32 $5,85 Caribbean. 24/12/16 Polyplacophora Chitonidae Chiton tuberculatus Panama F++ 35mm € 2,50 £2,16 $2,92 Caribbean. 24/12/16 Polyplacophora Chitonidae Chiton tuberculatus Panama F+++ 29mm+ € 3,00 £2,59 $3,51 Caribbean. -
The Youngest Representatives of the Genus Ribeiria Sharpe, 1853 from the Late Katian of the Prague Basin (Bohemia)
Estonian Journal of Earth Sciences, 2015, 64, 1, 84–90 doi: 10.3176/earth.2015.15 The youngest representatives of the genus Ribeiria Sharpe, 1853 from the late Katian of the Prague Basin (Bohemia) Marika Polechová Czech Geological Survey, Klárov 3, 11821 Prague 1, Czech Republic; [email protected] Received 2 July 2014, accepted 6 October 2014 Abstract. Ribeiria apusoides and Ribeiria johni sp. nov. are described from the late Katian of the Prague Basin (Bohemia) as the youngest representatives of the genus Ribeiria. The Ordovician ribeirioids from Bohemia (Perunica) show close affinities to the ribeirioids from Armorica and Iberia. The functional morphology of ribeirioids, mainly the pedal muscle system, is discussed, based on very well-preserved specimens of R. apusoides. The ribeirioids attained their diversity in the Lower Ordovician, since the Middle Ordovician their diversity declines, and during the late Katian only three genera are known worldwide. They are unknown from the Hirnantian but the last ribeirioids are recorded from the lower Silurian in South China. Key words: Ribeirioida, systematics, functional morphology, Ordovician, Prague Basin. INTRODUCTION Pojeta & Runnegar (1976) briefly described and figured all known species of rostroconchs, including also species The study of rostroconchs was started by Martin (1809) of ribeirioids from the Ordovician of the Prague Basin and Sowerby (1815), but the systematic position of the (Czech Republic). The rich material of rostroconchs group was for a long time unclear. Rostroconchs were from the Czech Republic is one of the best-preserved allied mainly to bivalves (Branson et al. 1969) or materials. It includes ribeirioids from the late Katian even to arthropods (Schubert & Waagen 1904; Kobayashi (Králův Dvůr Formation), among them the worldwide 1933). -
Influence of Frederick (Ted) M. Bayer on Deep-Water Octocoral Research
Vol. 397: 7–10, 2009 MARINE ECOLOGY PROGRESS SERIES Published December 17 doi: 10.3354/meps08066 Mar Ecol Prog Ser Contribution to the Theme Section ‘Conservation and management of deep-sea corals and coral reefs’ OPENPEN ACCESSCCESS Influence of Frederick (Ted) M. Bayer on deep-water octocoral research Stephen D. Cairns* Department of Invertebrate Zoology, Smithsonian Institution, PO Box 37012, Washington, DC 20560, USA ABSTRACT: The impact of Ted Bayer’s research on octocorals was extraordinary and his studies will long be used by any student of the group Octocorallia. He leaves behind a legacy of 107 published papers on octocorals, in which he newly described 4 families, 1 subfamily, 48 genera, 2 subgenera, 186 species, and 10 subspecies. An annotated list of his new taxa and all of his manuscripts (including 9 unpublished) are given in an electronic supplement. Although he published on most octocoral families, his favorite groups were the deep-water calcaxonian families from the western Atlantic, central Pacific, and Antarctic; he was also an expert on the precious coral family Coralliidae. He facilitated the study of the subclass by publishing classifications of the higher taxa, an illustrated trilingual glossary of morpho- logical terms, a key to all genera (exclusive of the Pennatulacea), and an annotated bibliography of the literature of the group. He was the first to use scanning electron microscope (SEM) images of sclerites to describe species, and perfected that technique in the use of SEM stereo pairs. He also made a sig- nificant contribution to advances in the knowledge of octocoral axial microstructure, proving that all gorgoniids have a diagnostic type of axial mineralogy. -
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. -
Atkins Peel.Vp
Yochelcionella (Mollusca, Helcionelloida) from the lower Cambrian of North America CHRISTIAN J. ATKINS & JOHN S. PEEL Five named species of the helcionelloid mollusc genus Yochelcionella Runnegar & Pojeta, 1974 are recognized from the lower Cambrian (Cambrian Series 2) of North America: Yochelcionella erecta (Walcott, 1891), Y. americana Runnegar & Pojeta, 1980, Y. chinensis Pei, 1985, Y. greenlandica Atkins & Peel, 2004 and Y. gracilis Atkins & Peel, 2004, linking lower Cambrian outcrops along the present north-eastern seaboard. Yochelcionella erecta, an Avalonian species, is de- scribed for the first time; other species are derived from Laurentia. A revised concept of the Chinese species, Y. chinensis, is based mainly on a large sample from the Forteau Formation of western Newfoundland and the species may have stratigraphic utility between Cambrian palaeocontinents. • Key words: Yochelcionella, Helcionelloida, Mollusca, lower Cambrian (Cambrian Series 2), North America. ATKINS,C.J.&PEEL, J.S. 2008. Yochelcionella (Mollusca, Helcionelloida) from the lower Cambrian of North America. Bulletin of Geosciences 83(1), 23–38 (8 figures). Czech Geological Survey, Prague. ISSN 1214-1119. Manuscript re- ceived September 26, 2007; accepted in revised form January, 10, 2008; issued March 31, 2008. Christian J. Atkins, Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden; [email protected] • John S. Peel, Department of Earth Sciences (Palaeobiology) and Mu- seum of Evolution, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden; [email protected] A fossil referable to the helcionelloid mollusc Yochelcio- there is debate about its precise function and the orienta- nella Runnegar & Pojeta, 1974 was illustrated by Walcott tion of the shell. -
The Functional Morphology of the Cambrian Univalved Mollusks— Helcionellids
See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/236216830 The Functional Morphology of the Cambrian Univalved Mollusks— Helcionellids. 1 Article in Paleontological Journal · July 2000 CITATIONS READS 29 411 1 author: Pavel Parkhaev Russian Academy of Sciences 85 PUBLICATIONS 1,150 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Worldwide Cambrian molluscan fauna View project All content following this page was uploaded by Pavel Parkhaev on 29 May 2014. The user has requested enhancement of the downloaded file. Paleontological Journal, Vol. 34, No. 4, 2000, pp. 392–399. Translated from Paleontologicheskii Zhurnal, No. 4, 2000, pp. 32–39. Original Russian Text Copyright © 2000 by Parkhaev. English Translation Copyright © 2000 by åÄIä “Nauka /Interperiodica” (Russia). The Functional Morphology of the Cambrian Univalved Mollusks—Helcionellids. 1 P. Yu. Parkhaev Paleontological Institute, Russian Academy of Sciences, ul. Profsoyuznaya 123, Moscow, 117868 Russia Received October 21, 1998 Abstract—The soft-body anatomy of helcionellids is reconstructed on the basis of a morphofunctional analy- ses of their shells. Evidently, two systems for the internal organization of helcionellids are possible: the first corresponds to that of the gastropodian class; the second, to that of the monoplacophorian. INTRODUCTION maximum number of analogies and the least number of contradictions with recent animals. Intensive study of the Cambrian fauna and stratigra- phy during recent decades shows us a diverse biota of Helcionellids were common elements of the mala- this geological period. Mollusks are well represented cofauna in the Early–Middle Cambrian and achieved a among the numerous newly described taxa in a variety rather high taxonomic diversity in comparison with of groups. -
Recent Advances and Unanswered Questions in Deep Molluscan Phylogenetics Author(S): Kevin M
Recent Advances and Unanswered Questions in Deep Molluscan Phylogenetics Author(s): Kevin M. Kocot Source: American Malacological Bulletin, 31(1):195-208. 2013. Published By: American Malacological Society DOI: http://dx.doi.org/10.4003/006.031.0112 URL: http://www.bioone.org/doi/full/10.4003/006.031.0112 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Amer. Malac. Bull. 31(1): 195–208 (2013) Recent advances and unanswered questions in deep molluscan phylogenetics* Kevin M. Kocot Auburn University, Department of Biological Sciences, 101 Rouse Life Sciences, Auburn University, Auburn, Alabama 36849, U.S.A. Correspondence, Kevin M. Kocot: [email protected] Abstract. Despite the diversity and importance of Mollusca, evolutionary relationships among the eight major lineages have been a longstanding unanswered question in Malacology. Early molecular studies of deep molluscan phylogeny, largely based on nuclear ribosomal gene data, as well as morphological cladistic analyses largely failed to provide robust hypotheses of relationships among major lineages.