Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-25T08:26:06.833Z Has data issue: false hasContentIssue false

A global synthesis of the latest Ordovician Hirnantian brachiopod faunas

Published online by Cambridge University Press:  03 November 2011

Rong Jia-yu
Affiliation:
Nanjing Institute of Geology and Palaeontology, Academia Sinica, Chi-Ming-Ssu, Nanjing, People's Republic of China.
David A. T. Harper
Affiliation:
Department of Geology, University College, Galway, Ireland.

Abstract

A global review of new and existing data on the distribution of uppermost Ordovician (Hirnantian) brachiopods indicates the existence of at least three biogeographically distinct faunas. The typical Hirnantia fauna characterised subtropical and temperate latitudes and comprised a variety of ecological associations; the fauna reached its acme during the bohemicus and uniformis zones. Atypical Hirnantia faunas, developed marginal to Gondwana, are of low diversity and have few species in common with the typical Hirnantia fauna; their spatial distribution probably marked the margin of the polar ice sheets. The extinction of the Hirnantia fauna occurred in response to changes in sea level. Diverse and quite different faunas, including those from the Midcontinent of North America, Kolyma, the Oslo Region and probably Anticosti Island, occupied equatorial latitudes during the latest Ordovician. The Holorhynchus fauna, on evidence to date, predates the Hirnantia fauna.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amsden, T. W. 1974. Late Ordovician and early Silurian articulate brachiopods from Oklahoma, southwestern Illinois and eastern Missouri. OKLAHOMA GEOL SURV 119, 1154.Google Scholar
Amsden, T. W. 1986. Late Ordovician-Early Silurian strata in the central United States and the Hirnantian Stage. Part I—Paleoenvironment of the Keel-Edgewood oolitic province and the the Hirnantian strata of Europe, USSR and China. OKLAHOMA GEOL SURV 139, 155.Google Scholar
Amsden, T. W. & Barrick, J. E. 1986. Late Ordovician-Early Silurian strata in the central United States and the Hirnantian Stage. OKLAHOMA GEOL SURV 139, 195.Google Scholar
Apollonov, M. K., Bandaletov, S. M. & Nikitin, I. F. (eds). 1980. The Ordovician-Silurian Boundary in Kazakhstan. NAUKA KAZAKH SSSR PUBL HOUSE ALMA-ATA.Google Scholar
Baarli, B. G. & Harper, D. A. T. 1986. Relict Ordovician brachiopod faunas in the Lower Silurian of Asker, Oslo Region, Norway. NORSK GEOL TIDSSK 66, 8798.Google Scholar
Baillie, P. W., Banks, M. R. & Rickards, R. B. 1978. Early Silurian graptolites from Tasmania and their significance. SEARCH 9, 4647.Google Scholar
Bassett, D. A., Whittington, H. B. & Williams, A. 1966. The stratigraphy of the Bala district, Merionethshire. Q J GEOL SOC LONDON 122, 219271.Google Scholar
Benedetto, J. L. 1986. The first typical Hirnantia fauna from South America (San Juan Province, Argentine Precordillera). BIOSTRATIGR PALÉOZOÏQUE 4, 439–337, pls. 1–2.Google Scholar
Bennacef, A., Beuf, S., Biju-Duval, B., De Charpal, O., Gariel, O. & Rognon, P. 1971. Examples of cratonic sedimentation: Lower Paleozoic of Algerian Sahara. BULL AM ASSOC PET GEOL 55, 22252245.Google Scholar
Bergström, J. 1968. Upper Ordovician brachiopods from Västergötland, Sweden. GEOL PALAEONTOL 2, 135.Google Scholar
Beuf, S., Biju-Duval, V., de Charpal, O., Rognon, P., Gariel, O. & Bennacef, A. 1971. Les Grès du Paléozoique inférieur au Sahara—sédimentation et discontinuites, évolution structural d'un craton. PUBL INST FRANCE PÉT 18, 1464.Google Scholar
Boucot, A. J. 1975. Evolution and extinction rates controls. Amsterdam: Elsevier.Google Scholar
Brenchley, P. J. 1984. Late Ordovician extinctions and their relationship to the Gondwana Glaciation. In Brenchley, P. J. (ed.) Fossils and Climate, 291315. Chichester: John Wiley & Sons.Google Scholar
Brenchley, P. J. & Cocks, L. R. M. 1982. Ecological associations in a regressive sequence: the latest Ordovician of the Oslo-Asker district, Norway. PALAEONTOLOGY 25, 783815.Google Scholar
Brenchley, P. J. & Cullen, B. 1984. The environmental distribution of associations belonging to the Hirnantia fauna—Evidence from North Wales and Norway. In Bruton, D. L. (ed.) Aspects of the Ordovician System, 113125. Oslo: Universitetsforlaget.Google Scholar
Brenchley, P. J. & Newall, G. 1984. Late Ordovician environmental changes and their effects on faunas. In Bruton, D. L. (ed.) Aspects of the Ordovician System, 6579. Oslo: Universitetsforlaget.Google Scholar
Burrett, C. F. & Stait, B. 1985. South East Asia as part of an Ordovician Gondwanaland—a palaeobiogeographic test of a tectonic hypothesis. EARTH PLANET SCI LETT 75, 184190.CrossRefGoogle Scholar
Campsie, J., Johnson, G. L., Jones, J. E. & Rich, J. E. 1984. Episodic volcanism and evolutionary crises. EOS 65, 796800.CrossRefGoogle Scholar
Caputo, M. V. & Crowell, J. C. 1985. Migration of glacial centres across Gondwana during the Paleozoic Era. BULL GEOL SOC AM 96, 10201036.Google Scholar
Caputo, M. V. & Lima, E. C. 1984. Estratigrafia, Idade e Correlacao do Grupo Serra Grande. GEOL SOC BRASIL 2, 740753.Google Scholar
Xu, Chen & Lens, A. C. 1984. Ordovician graptolite zonation and correlation with specific reference to the Pacific faunal realm. N JB GEOL PALAONT MH 1984, 212222.Google Scholar
Cocks, L. R. M. 1972. The origin of the Silurian Clarkeia shelly fauna of South America, and its extension to West Africa. PALAEONTOLOGY 15, 623630.Google Scholar
Cocks, L. R. M. 1982. The commoner brachiopods of the latest Ordovician of the Oslo-Asker district, Norway. PALAEONTOLOGY 25, 755781.Google Scholar
Cocks, L. R. M., Brunton, C. H. C., Rowell, A. J. & Rust, I. C. 1970. The first Lower Palaeozoic fauna proved from South Africa. Q J GEOL SOC LONDON 125, 583603.CrossRefGoogle Scholar
Cocks, L. R. M. & Copper, P. 1981. The Ordovician-Silurian boundary at the eastern end of Anticosti Island. CAN J EARTH SCI 18, 10291034.Google Scholar
Cocks, L. R. M. & Fortey, R. A. 1982. Faunal evidence for oceanic separations in the Palaeozoic of Britain. J GEOL SOC LONDON 139, 465478.CrossRefGoogle Scholar
Cocks, L. R. M. & Fortey, R. A. 1986. New evidence on the South African Lower Palaeozoic: age and fossils reviewed. GEOL MAG 123, 437444.CrossRefGoogle Scholar
Cocks, L. R. M. & Fortey, R. A. 1988. Lower Palaeozoic facies and faunas around Gondwana. SPEC PUBL GEOL SOC LONDON (in press).Google Scholar
Cocks, L. R. M. & Price, D. 1975. The biostratigraphy of the Upper Ordovician and Lower Silurian of South-west Dyfed, with comments on the Hirnantia fauna. PALAEONTOLOGY 18, 703724.Google Scholar
Cocks, L. R. M. & Rickards, R. B. 1988. A global analysis of the Ordovician-Silurian boundary. BULL BR MUS NAT HIST (GEOL) 43, 1394.Google Scholar
Crowell, J. C., Suarez-Sorucco, R., & Rocha-Campos, A. C. 1981. The Silurian Cancaniri (Zapla) Formation of Bolivia, Argentina and Peru. In Hambrey, M. J. & Harland, W. B. (eds) Earth's Pre-Pleistocene Glacial Record, 902907. Cambridge: Cambridge University Press.Google Scholar
Destombes, J. 1968. Sur la nature glaciaire des sédiments du 2 me bani; Ashgill Supérieur de l'Anti Atlas (Maroc). CR ACAD SCI PARIS 267, 684689.Google Scholar
Destombes, J., Hollard, H. & Willefert, S. 1985. Lower Palaeozoic rocks of Morocco. In Holland, C. H. (ed.) Lower Palaeozoic Rocks of the World, vol. 4, Lower Palaeozoic of north-western and west-central Africa, 91336. Chichester: John Wiley.Google Scholar
Elkin, E. A., Obut, A. M. & Sennikov, I. Y. 1978. The Ordovician–Silurian Boundary in Gorny Altai. TRUDY AKAD NAUK SSSR INST GEOL GEOF SIBIRSK OTDEL 397, 514.Google Scholar
Elles, G. L. 1922. The age of the Hirnant Beds. GEOL MAG 59, 409414.CrossRefGoogle Scholar
Elles, G. L. 1923. The age of the Hirnant Beds. GEOL MAG 60, 559560.CrossRefGoogle Scholar
Fortey, R. A. & Cocks, L. R. M. 1986. Marginal faunal belts and their structural implications, with examples from the Lower Palaeozoic. J GEOL SOC LONDON 143, 151160.CrossRefGoogle Scholar
Hambrey, M. J. 1985. The Late Ordovician-Early Silurian glacial period. PALAEOGEOGR PALAEOCLIMATOL PALAEOECOL 51, 273289.CrossRefGoogle Scholar
Harper, D. A. T. 1979. The environmental significance of some faunal changes in the Upper Ardmillan successsion (upper Ordovician), Girvan, Scotland. SPEC PUBL GEOL SOC LONDON 8, 439445.Google Scholar
Harper, D. A. T. 1981. The stratigraphy and faunas of the Upper Ordovician High Mains Formation of the Girvan district. SCOTT J GEOL 17, 247255.CrossRefGoogle Scholar
Harper, D. A. T. 1984. Brachiopods from the Upper Ardmillan succession (Ordovician) of the Girvan district, Scotland. Part 1. PALAEONTOGR SOC MONOGR, 178.Google Scholar
Harper, D. A. T. 1986. Distributional trends within the Ordovician brachiopod faunas of the Oslo Region, south Norway. BIOSTRATIGR PALÉOZOÏQUE 4, 465475.Google Scholar
Harper, D. A. T. 1988. Ordovician-Silurian junctions in the Girvan district, S. W. Scotland. BULL MUS NAT HIST (GEOL) 43, 4552.Google Scholar
Havlíček, V. 1971. Brachiopodes de l'Ordovicien du Maroc. NOT MÉM SERV GEOL 230, 1135.Google Scholar
Havlíček, V. 1977. Brachiopods of the order Orthida in Czechoslovakia. ROZPR ÚSTŘ ÚST GEOL 44, 1327.Google Scholar
Havlíček, V. 1982. Ordovician in Bohemia: development of the Prague Basin and its benthic communities. SBOR GEOL VĚD GEOL 37, 103136.Google Scholar
Havlíček, V. & Branisa, L. 1980. Ordovician brachiopods of Bolivia. ROZPR CES AKAD RAD MAT PRI 90, 154.Google Scholar
Havlíček, V. & Massa, D. 1973. Brachiopodes de l'Ordovicien supérieur de Libye occidentale. Implications stratigraphiques regionales. GEOBIOS 6, 267290.Google Scholar
Havlíček, V. & Vanek, J. 1966. The biostratigraphy of the Ordovician of Bohemia. VĚST ÚSTRED ÚST GEOL 8, 769.Google Scholar
Ho, Xin-yi 1980. Tetracoral fauna of the Late Ordovician Guanyinqiao Formation, Bijie, Guizhou Province. PROF PAP STRATIGR PALAEONTOL 6, 145.Google Scholar
Ingham, J. K. & Wright, A. D. 1970. A revised classification of the Ashgill Series. LETHAIA 3, 233242.Google Scholar
Jaanusson, V. 1979. Ordovician. In Robison, A. & Teichert, C. (eds) Treatise on Invertebrate Paleontology, Part A, Introduction + Biogeography and Biostratigraphy, A136–A166. University of Kansas Press.Google Scholar
Jaanusson, V. 1982. The Siljan district. In Bruton, D. L. & Williams, S. H. (eds) Field Excursion Guide. 4th International Symposium on the Ordovician System. PAL CONTR UNIV OSLO 279, 1542.Google Scholar
Jaeger, Von H., Havlíček, V. & Schonlaub, H. P. 1975. Biostratigraphie der Ordovizium/Silur-Grenze in der Sudalpen. Ein Beitrag zur Dikussion um die Hirnantia-Fauna. VER GEOL BUNDES 4, 271289.Google Scholar
Jones, O. T. 1923. The Hirnant Beds and the base of the Valentian. GEOL MAG 23, 514519.CrossRefGoogle Scholar
Kielan, Z. 1960. Upper Ordovician trilobites from Poland and some related forms from Bohemia and Scandinavia. PALAEONT POLONICA 11, 1198.Google Scholar
Koren, T. N., Sobolevskaya, R. F., Mikhajlova, N. F. & Tzai, D. T. 1979. New evidence on graptolite succession across the Ordovician-Silurian boundary in the Asian part of the USSR. ACTA PALEONT POLONICA 24, 123136.Google Scholar
Koren, T. N., Oradovskaya, M. M., Pylma, L. Y., Sobolevskaya, R. F. & Chugaeva, M. N. 1983. The Ordovician–Silurian Boundary in the Northeast of the USSR, 1192. Leningrad: Nauka.Google Scholar
Kul'kov, N. P. & Severgina, L. G. 1987. Ordovician and Silurian boundary in Gorny Altai. SER GEOL 9, 6974.Google Scholar
Lamont, A. 1935. The Drummuck Group, Girvan; a stratigraphical revision with descriptions of new fossils from the lower part of the group. TRANS GEOL SOC GLASGOW 19, 288334.CrossRefGoogle Scholar
Lamont, A. 1949. New species of Calymenidae from Scotland and Ireland. GEOL MAG 86, 313323.CrossRefGoogle Scholar
Laurie, J. R. 1982. The taxonomy and biostratigraphy of the Ordovician and Early Silurian articulate brachiopods of Tasmania. Unpublished Ph.D. Thesis, University of Tasmania.Google Scholar
Lespérance, P. J. 1974. The Hirnantian fauna of the Percé area (Quebec) and the Ordovician-Silurian boundary. AM J SCI 274, 1030.Google Scholar
Lespérance, P. J. 1985. Faunal distributions across the Ordovician-Silurian boundary, Anticosti Island and Percé, Quebec, Canada. CAN J EARTH SCI 22, 838849.CrossRefGoogle Scholar
Lespérance, P. J. & Sheehan, P. M. 1976. Brachiopoda from the Hirnantian Stage (Ordovician-Silurian) at Percé, Quebec. PALAEONTOLOGY 19, 719731.Google Scholar
Marek, L. & Havlíček, V. 1967. The articulate brachiopods of the Kosov Formation (Upper Ashgillian). VĚST ÚSTR ÚST GEOL 42, 275284.Google Scholar
McClure, H. A. 1978. Early Palaeozoic glaciation in Arabia. PALAEOGEOGR PALAEOCLIMATOL PALAEOECOL 25, 315326.Google Scholar
M'Coy, F. 1851. On some new Cambro-Silurian fossils. ANN MAG NAT HIST 8, 387409.Google Scholar
Melou, M. 1987. Decouverte de Hirnantia sagittifera (M'Coy, 1851) Orthida Brachiopoda dans l'Ordovicien superieur (Ashgillien) de l'extremité occidentale du Massif Armoricain. GEOBIOS 20, 679686.Google Scholar
Mergl, M. 1983. New brachiopods (Cambrian-Ordovician) from Algeria and Morocco (Mediterranean Province). CASOPIS PRO MIN GEOL 28, 337347, pls. 1–14.Google Scholar
Mikhajlova, N. F. 1970. On the discovery of Glyptograptus persculptus (Salter) in the Dalmanitina Beds of Kazakhstan. ISV AKAD NAUK ESTONIAN SSR CHEM GEOL 19, 177178.Google Scholar
Mu, En-zhi, Zhu, Zhao-ling, & Rong, Jia-yu 1978. The Ordovician strata in the vicinity of Shuanghe, Changning district of Sichuan. ACTA STRAT SINICA 2, 105121.Google Scholar
Mu, En-Zhi et al. 1980. Ordovician graptolite sequences and biogeographic regions in China. In Scientific papers on geology for international exchange, prepared for the 26th Geological Congress. 4, Stratigraphy and Palaeontology, 3542. Beijing: Beijing Press.Google Scholar
Mu, En-zhi, Zhu, Zhao-ling, Lin, Yao-kun & Wu, Hong-li 1984. The Ordovician-Silurian boundary in Yichang, Hubei. In Stratigraphy and palaeontology of systemic boundaries in China. Ordovician-Silurian Boundary 1, 1541. Nanjing: Nanjing Institute of Geology and Palaeontology, Academia Sinica.Google Scholar
Mu, En-zhi & Rong, Jia-yu 1983. On the international Ordovician and Silurian boundary. J STRAT 7, 8191.Google Scholar
Neuman, R. B. 1968. Paleogeographic implications of Ordovician shelly fossils in the Magog belt of the Northern Appalachian region. In Zen, E. A., White, W. S., Hadley, J. B. & Thompson, J. B. Jr. (ed) Studies of Appalachian Geology: Northern and Maritime, 3548. New York: Interscience.Google Scholar
Ni, Yu-nan, Xu, Han-kui & Cheng, Ting-en 1981. Boundary of the Ordovician-Silurian in the Xianza area, Xizang. J STRAT 5, 146147.Google Scholar
Nicholson, R. 1979. Caledonian correlations: Britain and Ireland. SPEC PUBL GEOL SOC LONDON 8, 318.CrossRefGoogle Scholar
Nikiforova, O. I. & Sapelnikov, V. P. 1973. Some early pentamerids of the Zerashan Mountains. TRUDY INST GEOL GEOCHIM URAL 99, 6482.Google Scholar
Nikitin, I. F. 1972. Ordovician of Kazakhstan, pt. 1. Stratigraphy. Alma Ata: Nauka Kazakh SSSR Publ House.Google Scholar
Nikitin, I. F. 1976. Ordovician–Silurian deposits in the Chu-Illi Mountains (Kazakhstan) and the problem of the Ordovician–Silurian boundary. In Bassett, M. G. (ed.) The Ordovician System: Proceedings of a Palaeontological Association Symposium, Birmingham, Sept. 1974, 293300. Cardiff: University of Wales Press and National Museum of Wales.Google Scholar
Owen, A. W. 1986. The uppermost Ordovician (Hirnantian) trilobites of Girvan, SW Scotland with a review of coeval trilobite faunas. TRANS R SOC EDINBURGH EARTH SCI 77, 231239.Google Scholar
Raup, D. & Sepkoski, J. J. 1984. Periodicity of extinctions in the geologic past. PROC NAT ACAD SCI USA 81, 801805.Google Scholar
Reed, F. R. C. 1915. Supplementary Memoir on new Ordovician and Silurian fossils from the Northern Shan States. PALAEONT INDICA 6, 1122.Google Scholar
Rong, Jia-yu. 1979. The Hirnantia fauna of China with comments on the Ordovican-Silurian boundary. ACTA STRAT SINICA 3, 18.Google Scholar
Rong, Jia-yu 1984a. Distribution of the Hirnantia fauna and its meaning. In Bruton, D. L. (ed.) Aspects of the Ordovician System, 101112, Oslo: Universitetsforlaget.Google Scholar
Rong, Jia-yu 1984b. Brachiopods of Latest Ordovician in the Yichang District, Western Hubei, Central China. In Stratigraphy and Palaeontology of Systemic Boundaries in China: Ordovician-Silurian 1, 111176.Google Scholar
Rong, Jia-yu 1986. Ecostratigraphy and community analysis of Late Ordovician and Silurian in southern China. PAL SOC CHINA, 123.Google Scholar
Rong, Jia-yu & Han, Nai-ren 1986. Preliminary report on Upper Ordovician (Mid-Ashgillian) brachiopods from Yushan, northeastern Jiangxi (Eastern China). In Rachebouef, P. R. & Emig, C. C. (eds.) Les Brachiopodes fossiles et actuels. BIOSTRATIGR PALÉOZOIQUE 4, 485490.Google Scholar
Rong, Jia-yu & Sun, Dong-li 1983. A latest Ordovician brachiopod fauna from Luxi, Western Yunnan, S. China. In Papers for the Symposium on the Cambrian-Ordovician and Ordovician-Silurian boundaries, Nanjing, China, October 1983, 138.Google Scholar
Rong, Jia-yu & Xu, Han-kui 1983. Terminal Ordovicial Hirnantia fauna of the Xainza District, Northern Xizang (N. Tibet). In Papers for the Symposium on the Cambrian-Ordovician and Ordovician-Silurian boundaries, Nanjing, China, October, 1983, 139.Google Scholar
Rozman, Kh.S. 1977. Biostratigraphy and Zoogeography of the Upper Ordovician of North Asia and North America. ACAD SCI USSR ORD RED BAN LAB GEOL INST TRANS 305, 3170 (in Russian).Google Scholar
Rukavishnikova, T. B. & Sapelnikov, V. P. 1973. New taxa of late Ashgillian Pentameracea in Kazahkstan. TRUDY INST GEOL GEOCHIM URAL 99, 89114.Google Scholar
Sanchez, T. M. 1985. El genero Modiolopsis (Bivalvia, Modiomorphoida) en el Ashgilliano de la Sierra de Villicum y la comunidad de Hirnantia-Modiolopsis. REUN COMUNIC CIENT ASS PALEONT ARGENTINA, 5859.Google Scholar
Sapelnikov, V. P. & Rukavishnikova, T. B. 1975. Upper Ordovician, Silurian and Devonian pentamerids of Kazakhstan. AKAD NAUKA SSSR URAL.Google Scholar
Schonlaub, H. P. 1971. Palaeo-environmental studies at the Ordovician/Silurian Boundary in the Carnic Alps. In Colloque Ordovicien-Silurien, Brest, Sept. 1971. MEM BUR RECH GEOL MIN 73, 367378.Google Scholar
Scotese, C. R., Bambach, R. K., Barton, C., Voo, R. V. D. & Ziegler, A. M. 1979. Paleozoic base maps. J GEOL 87, 217277.Google Scholar
Sheehan, P. M. 1973. The relation of Late Ordovician glaciation to the Ordovician-Silurian changeover in North American brachiopod faunas. LETHAIA 6, 147154.Google Scholar
Sheehan, P. M. 1975. Brachiopod synecology in a time of crisis (Late Ordovician-Early Silurian). PALEOBIOLOGY 1, 205212.Google Scholar
Sheehan, P. M. 1979. Swedish Late Ordovician marine benthic assemblages and their bearing on brachiopod zoogeography. In Gray, J. & Boucot, A. J. (eds.) Historical Biogeography, Plate Tectonics, and the Changing Environment, 6173. Corvallis: The Oregon State University Press.Google Scholar
Sheehan, P. M. 1982. Brachiopod macroevolution at the Ordovician-Silurian boundary. PROC N AM PALEONT CONV 3, 477481.Google Scholar
Spjeldnæs, N. 1981. Lower Palaeozoic palaeoclimatology. In Holland, C. H. (ed.) Lower Palaeozoic of the Middle East, Eastern and Southern Africa, and Antarctica, 199256. Chichester: John Wiley & Sons.Google Scholar
Stanley, S. M. 1984a. Temperature and biotic crises in the marine realm. GEOLOGY 12, 205208.Google Scholar
Stanley, S. M. 1984b. Mass extinctions in the ocean. SCIENTIFIC AM, 4654.Google Scholar
Størmer, L. 1967. Some aspects of the Caledonian geosyncline and foreland west of the Baltic Shield. Q J GEOL SOC LONDON 123, 183214.Google Scholar
Temple, J. T. 1965. Upper Ordovician brachiopods from Poland and Britain. ACTA PALAEONT POLONICA 10, 379450.Google Scholar
Temple, J. T. 1968. The Lower Llandovery (Silurian) brachiopods from Keisley, Westmorland. PALAEONTOGR SOC MONOGR, 158.Google Scholar
Wang, Xiao-feng, Zen, Qing-luan, Ni, Shi-mei, Xiang, Li-wen & Lai, Cai-gen. 1986. Rediscussion of the division and correlation of the Ordovician-Silurian boundary. BULL CHINESE ACAD GEOL SCI 12, 157164.Google Scholar
Wang, Yu, Boucot, A. J., Jia-yu, Rong & Xue-chang, Yang 1987. Community paleoecology as a geologic tool: The Chinese Ashgillian-Eifelian (latest Ordovician through Devonian) as an example. GEOL SOC AM SPEC PAP 211, 1100.Google Scholar
Williams, A. & Wright, A. D. 1981. The Ordovician-Silurian boundary in the Garth area of southwest Powys, Wales. GEOL J 16, 139.CrossRefGoogle Scholar
Williams, S. H. 1983. The Ordovician-Silurian boundary graptolite fauna of Dob's Linn, southern Scotland. PALAEONTOLOGY 26, 605639.Google Scholar
Williams, S. H. 1986. Top Ordovician lowest Silurian of Dob's Linn. SPEC PUBL GEOL SOC LONDON 20, 165171.Google Scholar
Wright, A. D. 1968. A westward extension of the Upper Ashgillian Hirnantia fauna. LETHAIA 1, 352367.Google Scholar
Wright, A. D. 1985. The Ordovician-Silurian boundary at Keisley, northern England. GEOL MAG 122, 261273.Google Scholar
Young, G. M. 1981. Early Palaeozoic tillites of the northern Arabian Peninsula. In Hambrey, M. J. & Harland, W. B. (eds) Earth's Pre-Pleistocene Glacial Record, 275277. Cambridge: Cambridge University Press.Google Scholar
Yu, Jian-hua, Fang, Yi-ting & Zhang, Da-liang 1986. Ordovician-Silurian Boundary section at Sanlanpu, Xixiang, Shaanxi. NANJING UNIV J NAT SCI 22, 475487.Google Scholar
Zhang, Wen-tang, Chen, Xu, Xu, Han-kui, Wang, Jun-geng, Lin, Yao-kun & Chen, Jun-yuan 1964. Silurian of Northern Guizhou. In Paleozoic Rocks of Northern Guizhou, 79110. Nanjing: Nanjing Institute of Geology and Palaeontology, Academia Sinica.Google Scholar
Ziegler, A. M. 1965. Silurian marine communities and their environmental significance. NATURE 207, 270272.Google Scholar
Ziegler, A. M., Scotese, C. R., McKerrow, W. S., Johnson, M. E. & Bambach, R. K. 1979. Paleozoic paleogeography. ANN REV EARTH PLANET SCI 7, 473502.Google Scholar
Zonenshayn, L. P. & Gorodnitskiy, A. M. 1977. Paleozoic and Mesozoic Reconstructions of the Continents and Oceans, Article 1, Early and Middle Paleozoic Reconstructions. GEOTECTONICS 11, 8394.Google Scholar