Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-26T07:56:28.053Z Has data issue: false hasContentIssue false

Review of the Ordovician conodont zonal index Eoplacognathus suecicus Bergström, 1971

Published online by Cambridge University Press:  20 May 2016

Zhang Jian-Hua*
Affiliation:
Department of Geology and Geochemistry, University of Stockholm, S-106 91 Stockholm, Sweden

Abstract

Over 600 elements of the Ordovician conodont index Eoplacognathus suecicus Bergström, 1971, were obtained from the Segerstad and Skärlöv Limestones at the Lunne section, which is the type locality of E. suecicus, and at the Kullstaberg section both in Jämtland, Sweden. Specimens of E. suecicus from different stratigraphic levels and representing different growth stages show obvious morphological differences. The stratigraphically early elements of E. suecicus are very similar to the stratigraphically late elements of Eoplacognathus pseudoplanus (Viira), being distinguished mainly by the appearance of the secondary postero-lateral denticle row in the stelliplanate element. Eoplacognathus suecicus apparently was derived from E. pseudoplanus, and probably evolved into Eoplacognathus lindstroemi (Hamar).

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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

An, T.-X. 1987. The Lower Paleozoic Conodonts of South China. Beijing University Press, Beijing, 238 p.Google Scholar
An, T.-X., Zhang, F., Xiang, W.-D., Zhang, Y.-Q., Xu, W.-H., Zhang, H.-J., Jiang, D.-B., Yang, C.-S., Lin, L.-D., Cui, Z.-T., and Yang, X.-C. 1983. The Conodonts of north China and the adjacent regions. Science Press, Beijing, 223 p.Google Scholar
An, T.-X., and Zheng, Z.-C. 1990. The conodonts of the marginal areas around the Ordos Basin, North China. Science Press, Beijing, 201 p.Google Scholar
Barnes, C. R., and Poplawski, M. L. S. 1973. Lower and Middle Ordovician conodonts from the Mystic Formation, Quebec, Canada. Journal of Paleontology, 47:760790.Google Scholar
Bergström, S. M. 1971. Conodont biostratigraphy of the Middle and Upper Ordovician of Europe and Eastern North America. Geological Society of America Memoir, 127:83161.Google Scholar
Bergström, S. M. 1981. Family Polyplacognathidae, p. W129W131. In Robison, R. A. (ed.), Treatise on invertebrate paleontology, Part W, Miscellanea, Supplement 2 Conodonta. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Bergström, S. M. 1983. Biogeography, evolutionary relationships, and biostratigraphic significance of Ordovician platform conodonts. Fossils and Strata, 15:3558.Google Scholar
Bergström, S. M., and Carnes, J. B. 1977. Conodont biostratigraphy and paleoecology of Holston Formation (Middle Ordovician) and associated strata in eastern Tennessee. Geological Association of Canada Special Paper, 15:2757.Google Scholar
Chen, M.-J., and Zhang, J.-H. 1989. Ordovician conodonts from the Shitai Region, Anhui. Acta Micropalaeontologica Sinica, 6:213228.Google Scholar
Ding, L.-S., Chen, M.-J., Zhang, J.-H., Cao, H.-H., and Bao, D.-X. 1993. Cambrian to Ordovician conodonts, p. 155214. In Wang, C.-Y. (ed.), Conodonts of Lower Yangtze Valley—An Index to Biostratigraphy and Organic Metamorphic Maturity. Science Press, Beijing.Google Scholar
Dzik, J. 1976. Remarks on the evolution of Ordovician conodonts. Acta Palaeontologica Polonica, 21:395455.Google Scholar
Dzik, J. 1983. Relationships between Ordovician Baltic and North American Midcontinent conodont faunas. Fossils and Strata, 15:5985.Google Scholar
Dzik, J. 1994. Conodonts of the Mojcza Limestone. Palaeontologia Polonica, 53:43128.Google Scholar
Hamar, G. 1966. The Middle Ordovician of the Oslo Region, Norway 22. Preliminary report on conodonts from the Oslo-Asker and Ringerike districts. Norsk Geologisk Tidsskrift, 46:2783.Google Scholar
Harris, A. G., Bergström, S. M., Ethington, R. L., and Ross, R. J. Jr. 1979. Aspects of Middle and Upper Ordovician conodont biostratigraphy of carbonate facies in Nevada and southeast California and comparison with some Appalachian successions. Brigham Young University Geology Studies, 26:743.Google Scholar
Hünicken, M. A., and Ortega, G. C. 1987. Lower Llanvirn-Lower Caradoc (Ordovician) conodonts and graptolites from the Argentine Central Precordillera. p. 136145. In Austin, R. L. (ed.), Conodonts—investigative techniques and applications. Ellis Horwood Ltd., Chichester.Google Scholar
Jaanusson, V. 1982. Introduction to the Ordovician of Sweden, p. 19. In Bruton, D. L. and Williams, S. H. (eds.), IV International Symposium on the Ordovician System. Field excursion guide. Palaeontological Contributions from the University of Oslo, 279.Google Scholar
Lehnert, O., 1995. Ordovizische Conodonten aus der Präkordillere Westargentiniens: Ihre Bedeutung für Stratigraphie und Paläogeographie. Erlanger Geologische Abhandlungen, 125, 193 p.Google Scholar
Lindström, M. 1977. Genus Eoplacognathus, p. 127147. In Ziegler, W. (ed.), Catalogue of Conodonts. Volume 3. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart.Google Scholar
Löfgren, A. 1978. Arenigian and Llanvirnian conodonts from Jämtland, northern Sweden. Fossils and Strata, 13, 129 p.Google Scholar
Ni, S.-Z. 1981. Discussion on some problems of Ordovician Stratigraphy by means of conodonts in Eastern Part of Yangtze Gorges Region, p. 127134. In Paper on the 1st convention Micropalaeontological Society of China, Science Press, Beijing.Google Scholar
Sarmiento, G. N. 1991: Conodontos de la zona suecicus (Llanvirn Inferior) en la sierra de villicum, Precordillera de San Juan, Argentina. Revista Espanola de Micropaleontología, 23:113132.Google Scholar
Stouge, S. S. 1984. Conodonts of the Middle Ordovician Table Head Formation, western Newfoundland. Fossils and Strata, 16, 145 p.Google Scholar
Viira, V. 1967. Ordovician conodont succession in the Ohesaare core. Eesti NSV teaduste Akadeemia Toimetised, Keemia Geoloogia, 16:319329.Google Scholar
Viira, V. 1972. On Symmetry of some Middle Ordovician Conodonts. Geologica et Palaeontologica, 6:4549.Google Scholar
Viira, V. 1974. Ordovician conodonts of the East Baltic. Tallinn Valgus Publishers, 142 p.Google Scholar
Watson, S. T. 1988. Ordovician conodonts from the Canning Basin (W. Australia). Palaeontographica Abteilung, 203A:91147.Google Scholar
Zhang, J.-H. 1997. The Lower Ordovician conodont Eoplacognathus crassus Chen and Zhang, 1993. Geologische Forschengen Festschrift, 119:6165.Google Scholar
Zhang, J.-H. 1998. The Ordovician conodont genus Pygodus. Palaeontologia Polonica, 58:87105.Google Scholar
Zhang, J.-H., and Sturkell, E. F. F. 1998. Aserian and Lasnamägian (Middle Ordovician) conodont biostratigraphy and lithology at Kullstaberg and Lunne in Jämtland, central Sweden. Geologische Forschengen Festschrift, 120:7583.Google Scholar