Silurian Bivalvia from Chichagof Island, Southeast Alaska (Alexander terrane)


Authors: Kříž J, Blodgett RB, Rohr DM

Published in: Bulletin of Geosciences, volume 86, issue 2; pages: 241 - 258; Received 25 March 2011; Accepted in revised form 27 April 2011; Online 24 May 2011

Keywords: Bivalvia, Silurian, late Wenlock to early Ludlow, new taxa, Alexander terrane, Southeast Alaska, U.S.A., palaeoecology, slope facies, palaeogeography, Perunica, Baltica,

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The new Silurian Bivalvia Goniophora thula-Mytilarca boucoti Community from a new locality east of the Hoonah Airport on Chichagof Island, Southeast Alaska, U.S.A. is composed of 9 species [?Colpomya aff. hugini Liljedahl, 1994 and ?Colpomya aff. audae Liljedahl, 1994 (Colpomyidae); Modiolopsis aff. modiolaris Conrad, 1838 (Modiolopsidae); Mytilarca boucoti sp. nov. (Ambonychiidae); ?Schizodus sp. A and ?Schizodus sp. B (Schizodidae); Sanguinolites sp. (Sanguinolitidae); ?Modiomorpha sp. and Goniophora thula sp. nov. (Modiomorphinae)]. In this paper two new species are described. The Goniophora thula-Mytilarca boucoti Community most probably occupied a gently inclined upper slope environment lying seaward of a cyanobacterial reef front which marked the outer edge of a late Silurian carbonate platform (represented by the Kennel Creek Limestone). The fauna of this locality consists of a rich benthos, especially rich in brachiopods, but secondarily dominated by bivalves and gastropods. Cephalopods are rare, favositid tabulate corals are also present, but form only a very minor component. The new community is most closely related to the homologous and analogous late Wenlock Bivalvia community described from Gotland, Sweden, Baltica. Similar biotic ties are with the shallow water early Ludlow Janicula potens Community from the Prague Basin, Bohemia, Perunica. Cosmopolitanism is characteristic for the Silurian Bivalvia genera, which were dispersed in most regions of the world due to their relatively long pelagic larval life and relatively small distances between the basins, islands and continents in the Silurian. For the distribution of Bivalvia during the Silurian were more limiting physical factors like temperature, salinity, substrate, food, oxygen content, light, and depth. The fauna described here is from the Alexander terrane, an accreted terrane which appears to represent a rifted block of the eastern Siberian palaeocontinent. The latter interpretation is based on faunal affinities, notably brachiopods, but suggested by other groups such as gastropods and sponges, as well as on the basis of similarities in sedimentary succession.


Barrande, J. 1881. Systeme silurien du centre de la Boheme. Classe des Mollusques, ordre des Acéphalés 6. 342 pp, 356 pls. Prague & Paris.

Berg, H.C., Jones, D.L. & Richter, D.H. 1972. Gravina-Nutzotin Belt; tectonic significance of an upper Mesozoic sedimentary and volcanic sequence in southern and southeastern Alaska. U.S. Geological Survey Professional Paper 800-D, D1-D24.

Billings, E. 1874. (MS not published) On some of the fossils of the Arisaig Series of rocks. Paleozoic Fossils, Geological Survey Canada 2(1), 1-144.

Blodgett, R.B., Boucot, A.J., Rohr, D.M. & Pedder, A.E.H. 2010. The Alexander terrane of Alaska - a displaced fragment of Northeast Russia? Evidence from Silurian-Middle Devonian megafossils and stratigraphy. Memoirs of the Association of Australasian Palaeontologists 39, 323-339.

Blodgett, R.B., Rohr, D.M. & Boucot, A.J. 2002. Paleozoic links among some Alaskan accreted terranes and Siberia based on megafossils, 273-290. In Miller, E.L., Grantz, A. & Klemperer, S.L. (eds) Tectonic evolution of the Bering Shelf-Chukchi Sea - Arctic margin and adjacent landmasses. Geological Society of America Special Paper 360.

Blodgett, R.B., Rohr, D.M., Karl, S.M. & Baichtal, J.F. 2003. Early Middle Devonian (Eifelian) gastropods from the Wadleigh Limestone in the Alexander terrane of southeastern Alaska demonstrate biogeographic affinities with central Alaskan terranes (Farewell and Livengood) and Eurasia, 105-115. In Galloway, J.P. (ed.) Studies in Alaska by the U.S. Geological Survey, 2001. U.S. Geological Survey Professional Paper 1678.

Bogolepova, O.K. & Kříž, J. 1995. Ancestral forms of Bohemian type Bivalvia from the lower Silurian of Siberia (Tungusskaja Syneclise, Russia). Geobios 28(6), 691-699.View article

Boucot, A.J. & Kříž, J. 1999. Definition of the terms “homologous” and “analogous” community. In Boucot, A.J. & Lawson, J.D. (eds) Paleocommunities: a case study from the Silurian and Lower Devonian. World and Regional Geology Series 11, 32. xv + 895 pp. Cambridge University Press, Cambridge.

Chapman, F. 1908. A monograph of the Silurian bivalved Mollusca of Victoria. Memoirs of the National Museum, Melbourne 1908(2), 5-62.View article

Clough, J.G. & Blodgett, R.B. 1988. Silurian-Devonian algal reef mound complex of southwest Alaska, 246-250. In Geldsetzer, H. & James, N.P. (eds) Reefs, Canadian and adjacent areas. Canadian Society of Petroleum Geologists Memoir 13.

Cocks, L.R.M. & Scotese, C.R. 1991. The global biogeography of the Silurian Period, 109-122. In Bassett, M.G., Lane, P.D. & Edwards, D. (eds) The Murchison Symposium: proceedings of an international conference on The Silurian System. Special Papers in Palaeontology 44, 1-397.

Conrad, T.A. 1838. Report on the palaeontological department of the survey (of New York). New York Geological Survey Annual Report 2, 107-119.

Conrad, T.A. 1842. Observations on the Silurian and Devonian systems of the United States, with descriptions of new organic remains. Journal of the Academy of Natural Science of Philadelphia 8(2), 228-280.

Fischer, P. 1880-87. Manuel de conchyliologie et de paléontologie conchyliologique ou histoire naturelle des mollusques vivants et fossiles. 1880, pp. 1-112; 1881, pp. 113-304; 1882, pp. 305-416; 1883, pp. 417-608; 1884, pp. 609-688; 1885, pp. 689-896; 1886, pp. 897-1008; 1887, pp. 1009-1369. F. Savy, Paris.

Hall, J. 1847. Natural History of New York. Paleontology. Vol. 1. 338 pp., 88 pls. Geological Survey of New York, New York.

Hall, J. 1865. Account of some new or little known species of fossils from rocks of the age of the Niagara group. 18th Annual Report of New York State Cabinet, 48 pp (printed in advance).

Hall, J. 1867. Descriptions of some new fossils from the Niagara Group. New York State Cabinet of Natural History, 20th Annual Report, 308-401.

Hall, J. 1883. Lamellibranchiata plates and explanations. Natural History of New York, Paleontology 5(1), 1-20, pls 1-34, 36-41, 43-80.

Hall, J. 1884. Lamellibranchiata I, descriptions and figures of the Monomyaria of the Upper Helderberg, Hamilton, and Chemung groups. Natural History of New York, Geological Survey of New York, Paleontology 5(1), 1-268, pls 1-33, 81-92.

Hall, J. 1885. Lamellibranchiata 2, descriptions and figures of the Dimyaria of the Upper Helderberg, Hamilton, Portage, and Chemung Groups. Natural History of New York, Geological Survey of New York, Palaeontology 5(1), 1-540, pls 34-80, 93-96.

Hall, J. & Whitfield, R.P. 1869. Preliminary notice of the lamellibranchiate shells of the Upper Helderberg, Hamilton and Chemung groups, with others from the Waverly sandstones, Part 2, 80 pp.

Havlíček, V. & Štorch, P. 1990. Silurian brachiopods and benthic communities in the Prague Basin (Czechoslovakia). Rozpravy Ústředního ústavu geologického 48, 1-275.

Havlíček, V. & Štorch, P. 1999. Silurian and Lochkovian communities in the Prague basin (Barrandian area, Czech Republic), 200-228. In Boucot, A.J. & Lawson, J.D. (eds) Final report, project Ecostratigraphy. Paleocommunities: A case study from the Silurian and Lower Devonian. 895 pp. Cambridge University Press, Cambridge.

Hede, J.E. 1915. Skanes Colonusskiffer. Lunds Universitets arsskrift, N.F. 2, 11(6), 1-65.

Isberg, O. 1934. Studien über Lamellibranchiata des Leptaenakalkes id Dalarna. 493 pp. Hakan Ohlssons, Lund.

Janischevskij, M. 1918. On some representatives of the Upper Silurian fauna of the Caucasus. Annuaire de la Société Paléontologique de Russie 1917, 2(3), 47-64.

Jones, D.L., Irwin, W.P. & Ovenshine, A.T. 1972. Southeast Alaska; a displaced continental fragment? U.S. Geological Survey Professional Paper 800-B, B211-B217.

Karl, S.M. 1999. Preliminary geologic map of northeast Chichagof Island, Alaska. U.S. Geological Survey Open-File Report 96-53, 12 pp., 1 map sheet, scale 1 : 63,360.

Kayser, E. 1878. Die Fauna der ältesten Devon-Ablagerungen des Harzes. Text und Atlas. Abhandlungen zur geologischen Spezialkarte von Preussen und den Thüringischen Staaten 2(4), 23I, 1-295, 36 pls.

Kirk, E. 1927a. Pycnodesma, a new molluscan genus from the Silurian of Alaska: Proceedings of the United States National Museum 71(20), 1-9.View article

Kirk, E. 1927b. Pycinodesma, a new name for Pycnodesma Kirk not Schrammen. Journal of the Washington Academy of Sciences 17, 543.

Kirk, E. & Amsden, T.W. 1952. Upper Silurian brachiopods from southeastern Alaska. U.S. Geological Survey Professional Paper 233(C), 53-66.

Kříž, J. 1979. Silurian Cardiolidae (Bivalvia). Sborník geologických věd, Palaeontologie 22, 1-160.

Kříž, J. 1999a. Bivalvia dominated communities of Bohemian type from the Silurian and Lower Devonian carbonate facies, 229-252. In Boucot, A.J. & Lawson, J.D. (eds) Final report, project Ecostratigraphy. Paleocommunities: A case study from the Silurian and Lower Devonian. 895 pp. Cambridge University Press, Cambridge.

Kříž, J. 1999b. Silurian Bivalvia - Evolution, palaeoecology, palaeogeography, importance for biostratigraphy and correlation. Abhandlungen der Geologischen Bundesanstalt 54, 377-384.

Kříž, J. 2007. Origin, evolution and classification of the new superorder Nepiomorphia (Mollusca, Bivalvia, Lower Palaeozoic). Palaeontology 50(6), 1341-1365.View article

Kříž, J. 2008. A new bivalve community from the lower Ludlow of the Prague Basin (Perunica, Bohemia). Bulletin of Geosciences 83(3), 237-280.View article

Kříž, J. & Bogolepova, O.K. 1995. Cardiola signata Community (Bivalvia) in cephalopod limestones from Tajmyr (Gorstian, Silurian, Russia). Geobios 28(5), 573-583.View article

Kříž, J. & Steinová, M. 2009. Uppermost Ordovician bivalves from the Prague Basin (Hirnantian, Perunica, Bohemia). Bulletin of Geosciences 84(3), 409-436.View article

Lamarck, J.B.P.A. de M. de 1819. Histoire Naturelle des Animaux sans Vertebres 6, Part 1. 232 pp. Paris.

Lathram, E.H., Loney, R.A. & Condon, W.H. 1958. Progress map of the geology of the Juneau quadrangle, Alaska. U.S. Geological Survey Miscellaneous Investigations 276, 1 sheet, scale 1 : 250,000.

Lathram, E.H., Loney, R.A., Condon, W.H. & Berg, H.C. 1959. Progress map of the geology of the Juneau quadrangle, Alaska. U.S. Geological Survey Miscellaneous Investigations Map I-303, 1 sheet, scale 1 : 250,000.

Leonenok, N.I. 1955. Siluriyskiye otlozheniya Kos-Istekskogo rayona (Severnye Mugodzhary). Trudy Laboratorii Uglya Akademii Nauk SSSR 3, 116-225.

Liljedahl, L. 1983. Two silicified bivalves from Gotland. Sveriges Geologiska Undersökning, Serie C 799, 77(1), 1-51.

Liljedahl, L. 1984. Silurian silicified bivalves from Gotland. Sveriges Geologiska Undersökning, Serie C 804, 78(2), 1-82.

Liljedahl, L. 1985. Ecological aspects of a silicified bivalve fauna from the Silurian of Gotland. Lethaia 18(1), 53-66.View article

Liljedahl, L. 1991. Contrasting feeding strategies in bivalves from the Silurian of Gotland. Palaeontology 34(1), 219-235.

Liljedahl, L. 1992. Silurozodus, new genus, the oldest known member of the Trigonioida (Bivalvia, Mollusca). Paläontologische Zeitschrift 66(1/2), 51-65.

Liljedahl, L. 1994. Silurian nuculoid and modomorphid bivalves from Sweden. Fossils and Strata 33, 1-89.

Linné, C. 1758. Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Edit Decima, reformata. 824 pp. Holmiae.

Loney, R.A., Berg, H.C., Pomeroy, J.S. & Brew, D.A. 1963a. Reconnaissance geologic map of Chichagof Island and northwestern Baranof Island, Alaska. U.S. Geological Survey Miscellaneous Geologic Investigations Map I-388, 7 pp., 1 sheet, scale 1 : 250,000.

Loney, R.A., Condon, W.H. & Dutro, J.T., Jr. 1963b. Geology of the Freshwater Bay area, Chichagof Island, Alaska. U.S. Geological Survey Bulletin 1108-C, C1-C54, 2 sheets, scale 1 : 63,360.

McCoy, F. 1844. A synopsis of the characters of the Carboniferous Limestone fossils of Ireland. 274 pp. Privately printed, re-issued 1862, Williams & Norgate, London.

McGovney, J.E. 1989. Thornton reef, Silurian, northeastern Illinois. Canadian Society of Petroleum Geologists Memoir 13, 330-338.

McLearn, F.H. 1924. Palaeontology of the Silurian rocks of Arisaig, Nova Scotia. Memoir. Geological Survey of Canada 175(118), 1-179.

Miller, S.A. 1877. The American Palaeozoic fossils, a catalogue of the genera and species. 253 pp. Published by author, Cincinnati.

Murchison, R.I. 1839. The Silurian System founded on geological researches in the counties of Salop, Hereford, Radnor, Montgomery, Caermarthen, Brecon, Pembroke, Monmouth, Gloucester, Worcester and Stafford; with descriptions of the coalfields and overlying formations. i-xxxii, 768 pp. John Murray, London.

Newell, N.D. & LaRocque, A. 1969. Family Grammysiidae S.A. Miller, 1877, N819-N823. In Moore, R.C. (ed.) Treatise on invertebrate paleontology, Part N, Mollusca 6. Bivalvia. 951 pp. Geological Society of America & University of Kansas Press, Boulder & Lawrence.

Newell, N.D. & Boyd, D.W. 1975. Parallel evolution in early trigoniacean bivalves. Bulletin of the American Museum of Natural History 154(2), 55-162.

Nikiforova, O.I. & Obut, A.M. 1965. Siluriyskaya sistema. 529 pp. Nedra, Moscow.

Pedder, A.E.H. 2006. Zoogeographic data from studies of Paleozoic corals of the Alexander terrane, southeastern Alaska and British Columbia, 29-57. In Haggart, J.W., Enkin, R.J. & Monger, J.W.H. (eds) Paleogeography of the North American cordillera: Evidence for and against large-scale displacements. Geological Association of Canada, Special Paper 46.

Phillips, J. 1848. The Malvern hills, compared with the Palaeozoic districts of Abberley, Woolhope, May Hill, Tortworth, and Usk. Memoirs of the Geological Survey of Great Britain 2(2), 1-330.

Pojeta, J. Jr. 1971. Review of Ordovician Pelecypods. U.S. Geological Survey Professional Paper 695, 1-46.

Pojeta, J. & Gilbert-Tomlinson, J. 1977. Australian Ordovician pelecypod molluscs. Department of National Resources, Bureau of Mineral Resources, Geology and Geophysics Bulletin 174, 1-64.

Pojeta, J., Jr., Zhang, R. & Yang, Z. 1986. Systematic palaontology of the Devonian pelecypods of Guangxi and Michigan, 57-102. In Pojeta, J., Jr. (ed.) Devonian rocks and Lower and Middle Devonian pelecypods of Guangxi, China, and the Traverse Group of Michigan. U.S. Geological Survey Professional Paper 1394-A-G.

Rigby, J.K., Nitecki, M.H., Soja, C.M. & Blodgett, R.B. 1994. Silurian aphrosalpingid sphinctozoans from Alaska and Russia. Acta Palaeontologica Polonica 3, 341-391.

Rohr, D.M., Blodgett, R.B., Boucot, A.J. & Skaflestad, J. 2011. Upper Silurian facies and fauna of northeast Chichagof Island, Southeast Alaska [abstract]. 2011 Western Region Meeting SPE Pacific Section, AAPG 6-14 May 2011. Program with Abstract, p. 82.

Sanchez, T.M. 1991. El genero Dualina (Bivalvia, Praecardioida) en formacion Lipeon (Silurico), Sierra de Zapla, Provincia de Jujuy, Argentina. Ameghiniana 28(1-2), 31-34.

Sherrard, K. 1959. Some Silurian lamellibranchs from New South Wales. Proceedings of the Linnean Society of New South Wales 84(3), 356-372.

Sinicyna, I.N. 1964. Representatives of the Modiolopsidae Fischer from the Silurian sediments of Podolia. Vestnik Leningradskogo universiteta 24, 44-50. [in Russian]

Sinicyna, I.N. 1993. Klass Bivalvia - dvustvorchatyye mollyuski, 10-27. In Kiselev, G.N. (ed.) Atlas mollyuskov i brachiopod silura i devona yuzhnogo Tyan-Shanya. Izdatelstvo Sankt-Petersburgskogo Universiteta, St. Petersburg.

Sowerby, J. 1921. Manual of conchology, Vol. 4. 12 pp. I. Sowerby, London.

Stanley, S.M. 1970. Relation of shell form to life habits in the Bivalvia (Mollusca). Memoir of the Geological Society of America 125, 1-296.

Thorson, G. 1961. Length of pelagic larval life in marine bottom invertebrates as related to larval transport by ocean currents, 455-474. In Sears, M. (ed.) Oceanography. American Association for the Advancement of Science, Freeman and Company, Washington.

Ulrich, E.O. 1893. New and little known Lamellibranchiata from the Lower Silurian rocks of Ohio and adjacent states. Ohio Geological Survey Report 7(2), 627-693.

Verneuil, P.E.P. de&Murchison, R.I. 1844. Note sur les équivalents du systeme permien en Europe, suivie d’un coup d’oeil general sur l’ensemble de ses fossiles, et d’un tableau des especes. Bulletin de la Société Géologique de France, série 2, 1, 475-517.

Watkins, R. 1978. Bivalve ecology in a Silurian shelf environment. Lethaia 11(1), 41-56.View article

Watkins, R. 1979. Benthic community organization in the Ludlow Series of the Welsh Borderland. Bulletin of the British Museum (Natural History), Geology 31(3), 175-280.

Watkins, R. 1997. Paleoecology of Silurian reef bivalves, Racine Formation, North America. Lethaia 29(2), 171-180.View article

Watkins, R. & Berry, W.B.N. 1977. Ecology of a late Silurian fauna of graptolites and associated organisms. Lethaia 10(4), 267-286.View article