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Element morphology and taxonomic relationships of the Ordovician conodonts Phragmodus primus Branson and Mehl, 1933, the type species of Phragmodus Branson and Mehl, 1933, and Phragmodus undatus Branson and Mehl, 1933

Published online by Cambridge University Press:  20 May 2016

Stephen A. Leslie  and
Stig M. Bergström
Stephen A. Leslie
Affiliation:
Department of Geological Sciences, The Ohio State University, Columbus 43210
Stig M. Bergström
Affiliation:
Department of Geological Sciences, The Ohio State University, Columbus 43210
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Abstract

Rediscovery of Branson and Mehl's (1933b) classical outcrop of the Middle Ordovician Joachim Dolomite near Holstein in eastern Missouri, from which they described 32 new species and four new genera of conodonts, makes it possible to obtain the large topotype collections needed to interpret their taxa in terms of modern multielement taxonomy. Of special interest in their Holstein fauna is Phragmodus primus Branson and Mehl, 1933, by original designation the type species of Phragmodus Branson and Mehl, 1933, whose morphology and relationships have been very poorly understood. Study of topotype collections, as well as of Branson and Mehl's syntypes, has failed to reveal any notable morphological differences between the elements of P. primus and those of P. undatus Branson and Mehl, 1933, a very well known and widely distributed species in the Middle and Upper Ordovician Midcontinent Realm faunas. These species are herein considered to be synonymous. Because the original descriptions of P. primus and P. undatus were published simultaneously, neither name has priority over the other. However, P. undatus has figured far more prominently in the taxonomic and biostratigraphic conodont literature than P. primus and therefore we favor use of the former designation for this species. The recognition that P. primus and P. undatus are the same species extends the stratigraphic range of P. undatus downward to considerably below the Deicke K-bentonite, that is, well into the Blackriveran.

Type
Research Article
Information
Journal of Paleontology , Volume 69 , Issue 5 , September 1995 , pp. 967 - 974
Copyright
Copyright © The Paleontological Society 

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References

Andrews, H. E. 1967. Middle Ordovician conodonts from the Joachim Dolomite of eastern Missouri. Journal of Paleontology, 41:881–901.Google Scholar
Taixiang, An, Fang, Zhang, Weida, Xiang, Youqui, Zhang, Wenhao, Xu, Huijian, Zhang, Debiao, Jiang, Changsheng, Yang, Liandi, Lin, Zhantang, Cui, and Xinchang, Yang. 1983. The Conodonts of North China and the Adjacent Regions. Science Press of China, 223 p. [in Chinese].Google Scholar
Bauer, J. A. 1989. Conodont biostratigraphy and paleoecology of Middle Ordovician rocks in eastern Oklahoma. Journal of Paleontology, 63:92–107.Google Scholar
Bergström, S. M., and Sweet, W. C. 1966. Conodonts from the Lexington Limestone (Middle Ordovician) of Kentucky and its lateral equivalents in Ohio and Indiana. Bulletins of American Paleontology, 50(299):271–441.Google Scholar
Branson, E. B. 1938. Stratigraphy and paleontology of the Lower Mississippian of Missouri. Part I. The University of Missouri Studies, 13(3):1–208.Google Scholar
Branson, E. B., and Mehl, M. B. 1933a. Conodont studies Number 1. Introduction. The University of Missouri Studies, 8(1):5–17.Google Scholar
Branson, E. B., and Mehl, M. B. 1933b. Conodonts from the Joachim (middle Ordovician) of Missouri. The University of Missouri Studies, 8(2):77–100.Google Scholar
Branson, E. B., and Mehl, M. B. 1933c. Conodonts from the Plattin (middle Ordovician) of Missouri. The University of Missouri Studies, 8(2):101–120.Google Scholar
Clark, D. L., Sweet, W. C., Bergström, S. M., Klapper, G., Austin, R. L., Rhodes, F. H. T., Müller, K. J., Ziegler, W., Lindström, M., Miller, J. F., and Harris, A. G. 1981. Conodonta. In Robinson, R. A. (ed.), Treatise on Invertebrate Paleontology, Pt. W, Supplement 2. Geological Society of America and University of Kansas Press, 202 p.Google Scholar
Dzik, J. 1976. Remarks on the evolution of Ordovician conodonts. Acta Paleontologica Polonica, 21:395–455.Google Scholar
Hall, J. C. 1986. Conodonts and conodont biostratigraphy of the Middle Ordovician in the western overthrust region and Sequatchie Valley of the Southern Appalachians. Unpubl. Ph.D. dissertation, The Ohio State University, 345 p.Google Scholar
Harris, A. G., and Sweet, W. C. 1989. Mechanical and chemical techniques for separating microfossils from rock, sediment, and residue matrix, p. 70–86. In Feldmann, R. M., Chapman, R. E., and Hannibal, J. T. (eds.), Paleotechniques. The Paleontological Society Special Publication No. 4.Google Scholar
Hass, W. H. 1959. Conodonts from the Chappel Limestone of Texas. U.S. Geological Survey Professional Paper 294J:365–400.Google Scholar
Huff, W. D., and Kolata, D. R. 1990. Correlation of the Ordovician Deicke and Millbrig K-bentonites between the Mississippi Valley and the Southern Appalachians. American Association of Petroleum Geologists Bulletin, 74:1736–1747.Google Scholar
International Code of Zoological Nomenclature. Third Edition. 1985. University of California Press.Google Scholar
Kennedy, D. J. 1980. A restudy of conodonts described by Branson & Mehl, 1933, from the Jefferson City Formation, Lower Ordovician, Missouri. Geologica et Paleontologica, 14:45–76.Google Scholar
Moskalenko, T. A. 1973. Conodonts of the Middle and Upper Ordovician on the Siberian Platform. Academy of Sciences of the USSR, Siberian Branch «Nauka», Transactions of the Institute of Geology and Geophysics, 137:1–143 [in Russian].Google Scholar
Nassedkina, V. A. 1975. On Ordovician conodonts from the western slope of the Urals, p. 110–127. In Novye miospori, foraminiferi, ostracodi i konodonti, Paleozoya i Mesozoya Urala. Acamiya Nauk SSR, Uralskii Nauchnii Tcenter. [in Russian].Google Scholar
Stauffer, C. R. 1935. Conodonts of the Glenwood Beds. Bulletin of the Geological Society of America, 46:125–168.CrossRefGoogle Scholar
Sweet, W. C. 1979. Conodonts and conodont biostratigraphy of Post-Tyrone rocks of the Cincinnati region. U.S. Geological Survey Professional Paper 1066-G:G1–G25.Google Scholar
Sweet, W. C. 1981a. Genus Phragmodus Branson and Mehl, 1933, p. 245–270. In Ziegler, W. (ed.), Catalogue of Conodonts, Volume IV. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart.Google Scholar
Sweet, W. C. 1981b. Macromorphology of elements and apparatuses, p. W5–W20. In Robinson, R. A. (ed.), Treatise on Invertebrate Paleontology, Pt. W, Supplement 2, Conodonta. Geological Society of America and University of Kansas.Google Scholar
Sweet, W. C. 1984. Graphic correlation of upper Middle and Upper Ordovician rocks, North American Midcontinent Province, USA, p. 23–35. In Bruton, D. L. (ed.), Aspects of the Ordovician System. Palaeontological Contributions from the University of Oslo, 195, Universitetsforlaget.Google Scholar
Sweet, W. C. 1987. Distribution and significance of conodonts in Middle and Upper Ordovician strata of the Upper Mississippi Valley region. Minnesota Geological Survey Report of Investigations, 35:167–172.Google Scholar
Sweet, W. C., and Bergström, S. M. 1972. Multielement taxonomy and Ordovician conodonts. Geologica et Paleontologica Sonderband 1:20–42.Google Scholar
Templeton, J. L., and Willman, H. B. 1963. Champlainian Series (Middle Ordovician) in Illinois. Illinois State Geological Survey Bulletin 898, 260 p.Google Scholar
Thompson, T. L. 1991. Paleozoic succession in Missouri. Part 2. Ordovician System. Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigation 70, 292 p.Google Scholar
Votaw, R. B. 1971. Conodont biostratigraphy of the Black River Group (Middle Ordovician) and equivalent rocks of the eastern Midcontinent, North America. Unpubl. Ph.D. dissertation, The Ohio State University, 161 p.Google Scholar
Watson, S. T. 1988. Ordovician conodonts from the Canning Basin (W. Australia). Palaeontographica Abteilung A, 203:91–147.Google Scholar
Webers, G. F. 1966. The Middle and Upper Ordovician conodont faunas of Minnesota. Minnesota Geological Survey Special Publication, 4, 123 p.Google Scholar