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Element association and morphology in some Middle Ordovician platform-equipped conodonts

Published online by Cambridge University Press:  14 July 2015

Anita Löfgren  and
Zhang Jianhua
Anita Löfgren
Affiliation:
Department of Geology, Sölvegatan 13, SE-223 62 Lund, Sweden,
Zhang Jianhua
Affiliation:
Department of Geology and Geochemistry, Stockholm University, Stockholm, Sweden
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Abstract

Conodont elements other than those with platform ledges along the processes have often been unrecognized or disregarded in reconstructions and phylogenetic discussions of Ordovician “platform conodont genera.” The platform elements are larger than the other element types and often exhibit more rapid evolutionary changes in morphology. Nevertheless, to understand the evolution of, and relationships between and among “platform genera,” it is necessary to also consider the associated ramiform and geniculate elements. Thus, on the basis of large collections, together comprising 10,800 elements from Sweden and southern China, all element types of Lenodus antivariabilis (An, 1981), L. variabilis (Sergeeva, 1963), Yangtzeplacognathus crassus (Chen and Zhang, 1993) and Eoplacognathus pseudoplanus (Viira, 1974) are described and discussed. All these species had seven morphologically distinct element types, and probably seventeen individual elements in each apparatus. Ancestors and descendants of these species are discussed more briefly and it is concluded that the ramiform and geniculate elements also are characteristic within each lineage.

Type
Research Article
Information
Journal of Paleontology , Volume 77 , Issue 4 , July 2003 , pp. 721 - 737
Copyright
Copyright © The Paleontological Society

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References

Albanesi, G. L. 1998. Taxonomia de conodontes de las secuencias ordovicicas del Cerro Potrerillo, Precordillera Central de San Juan, R. Argentina. Actas de la Academia Nacional de Ciencias, 12:101–252.Google Scholar
Aldridge, R. J., Purnell, M. A., Gabbott, S. E., and Theron, J. N. 1995. The apparatus architecture and function of Promissum pulchrum Kovács-Endrödy (Conodonta, Upper Ordovician), and the prioniodontid plan. Philosophical Transactions of the Royal Society of London, Series B, 347:275–291.Google Scholar
Tai-Xiang, An. 1981. Recent progress in Cambrian and Ordovician conodont biostratigraphy of China. Geological Society of America Special Paper, 187:209–25.CrossRefGoogle Scholar
Tai-Xiang, An. 1987. The lower Paleozoic conodonts of south China! (in Chinese). Publishing House of Geology, Beijing, 238 p., 35 pls.Google Scholar
Tai-Xiang, An, Du, Guo-Qing, and Gao, Qin-Qin. 1985. Ordovician conodonts from Hubei, China. Publishing House of Geology, Beijing, 64 p.Google Scholar
Bagnoli, G., and Stouge, S. 1997. Lower Ordovician (Billingenian–Kunda) conodont zonation and provinces based on sections from Horns Udde, north Öland, Sweden. Bolletino della Società Paleontologica Italiana, 35(2):109–63, 7 text-figs., 8 pls., Modena.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, 47:760–790.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, 127:83–161.CrossRefGoogle Scholar
Jun-yuan, Chen, and Lindström, M. 1991. Cephalopod Septal Strength Indices (SSI) and depositional depth of Swedish Orthoceratite limestone. Geologica et Palaeontologica, 25:5–18.Google Scholar
Min-Juan, Chen, and Zhang, Jian-Hua. 1984. Middle Ordovician conodonts from Tangshan, Nanjing. Acta Micropalaeontologica Sinica, 1:120–136.Google Scholar
Min-Juan, Chen, and Zhang, Jian-Hua. 1989. Ordovician conodonts from the Shitai region, Anhui (in Chinese with an English summary). Acta Micropaleontologica Sinica, 6(3):213–228.Google Scholar
Liansheng, Ding, Chen, Min-Juan, Zhang, Jian-Hua, Cao, Hai-Hong, and Bao, Dexian. 1993. Cambrian to Ordovician conodonts, p. 155–214. In Chengyuan, Wang (ed.), Conodonts of Lower Yangtze Valley—An Indexes to Biostratigraphy and Organicmetamorphic Maturity. Science Press, Beijing.Google Scholar
Donoghue, P. C. J. 2001. Conodonts meet cladistics: recovering relationships and assessing the completeness of the conodont fossil record. Palaeontology, 44:65–93.CrossRefGoogle Scholar
Dzik, J. 1976. Remarks on the evolution of Ordovician conodonts. Acta Palaeontologica Polonica, 21:395–455.Google Scholar
Dzik, J. 1983. Relationships between Ordovician Baltic and North American Midcontinent conodont faunas. Fossils and Strata, 15:59–85.Google Scholar
Dzik, J. 1994. Conodonts of the Mojcza Limestone. In Dzik, J., Olempska, E., and Pisera, A. (eds.), Ordovician Carbonate Platform Ecosystem of the Holy Cross Mountains. Palaeontologica Polonica, 53:43–128.Google Scholar
Erlström, M., Ahlberg, P., and Löfgren, A. 2001. Lower Palaeozoic stratigraphy at Lyby and Tängelsås, central Scania, southern Sweden. GFF, 123:7–14.CrossRefGoogle Scholar
Fortey, R. A., Harper, D. A. T., Ingham, J. K., Owen, A. W., and Rushton, A. W. A. 1995. A revision of the Ordovician series and stages from the historical type area. Geological Magazine, 132:15–30.CrossRefGoogle Scholar
Hamar, G. 1966. Preliminary report on conodonts from the Oslo-Asker and Ringerike districts. Norsk Geologisk Tidsskrift, 46:27–83.Google Scholar
Jaanusson, V. 1982. Introduction to the Ordovician of Sweden, p. 1–9. In Bruton, D. L. and Williams, S. H. (eds.), Field Excursion Guide, IV International Symposium on the Ordovician System. Palaeontological Contributions from the University of Oslo, 279.Google Scholar
Jeppsson, L., Anehus, R., and Fredholm, D. 1999. The optimal acetate buffered acetic acid technique for extracting phosphatic fossils. Journal of Paleontology, 73:964–972.CrossRefGoogle Scholar
Jeppsson, L., Fredholm, D., and Mattiasson, B. 1985. Acetic acid and phosphatic fossils—a warning. Journal of Paleontology, 59:952–956.Google Scholar
Klapper, G., and Philip, G. M. 1971. Devonian conodont apparatuses and their vicarious skeletal elements. Lethaia, 4:429–452.CrossRefGoogle Scholar
Landing, E. 1976. Early Ordovician (Arenigian) conodont and graptolite biostratigraphy of the Taconic allochthon, eastern New York. Journal of Paleontology, 50:614–646.Google Scholar
Lehnert, O. 1995. Ordovizische Conodonten aus der Präkordillere Westargentiniens: Ihre Bedeutung für Stratigraphie und Paläogeographie. Erlanger geologische Abhandlungen, 125:1–193.Google Scholar
Lehnert, O., and Keller, M. 1993. Posicion estratigrafica de los arrecifes arenigianos en la Precordillera Argentina. Document Laboratoire Geologique de Lyon, 125:263–275.Google Scholar
Lindström, M. 1955. Conodonts from the lowermost Ordovican strata of south-central Sweden. Geologiska Föreningens i Stockholm Förhandlingar, 76:517–604.CrossRefGoogle Scholar
Lindström, M. 1971. Lower Ordovician conodonts of Europe. Geological Society of America Memoir, 127:21–61.CrossRefGoogle Scholar
Lindström, M. 1984. Baltoscandic conodont life environments in the Ordovician: sedimentologic and paleogeographic evidence. Geological Society of America Special Paper, 196:33–42.CrossRefGoogle Scholar
Löfgren, A. 1978. Arenigian and Llanvirnian conodonts from Jämtland, northern Sweden. Fossils and Strata, 13:1–129.Google Scholar
Löfgren, A. 1985. Early Ordovician conodont biozonation at Finngrundet, south Bothnian Bay, Sweden. (Geology of the southern Bothnian Sea. Pt. III). Bulletin of the Geological Institutions of the University of Uppsala, 10:115–28. Uppsala.Google Scholar
Löfgren, A. 1990. Non-platform elements of the Ordovician conodont genus Polonodus . Paläontologische Zeitschrift, 64:245–259.CrossRefGoogle Scholar
Löfgren, A. 1995. The middle Lanna/Volkhov Stage (middle Arenig) in Sweden and its conodont fauna. Geological Magazine, 132:693–711.CrossRefGoogle Scholar
Löfgren, A. 2000a. Conodont biozonation in the upper Arenig of Sweden. Geological Magazine, 137:53–65.CrossRefGoogle Scholar
Löfgren, A. 2000b. Early to early Middle Ordovician conodont biostratigraphy of the Gillberga quarry, northern Öland, Sweden. GFF, 122:321–338.CrossRefGoogle Scholar
Nielsen, A. 1995. Trilobite systematics, biostratigraphy and palaeoecology of the Lower Ordovician Komstad Limestone and Huk Formations, southern Scandinavia. Fossils and Strata, 38:1–374.Google Scholar
Shizhao, Ni. 1981. Discussion on some problems of Ordovician stratigraphy by means of conodonts in eastern part of Yangtze Gorges Region, p. 127–134. In Paper on the 1st Convention of the Micropalaeontological Society of China. Science Press, Beijing.Google Scholar
Shizhao, Ni, and Zhihong, Li. 1987. The Ordovician conodonts from Yangtze Gorges area, p. 102–114, 386–447. In Biostratigraphy of the Yangtze Gorges Area (2) Early Paleozoic Era. Geological Publishing House, Beijing.Google Scholar
Nordlund, U. 1989. Lithostratigraphy and sedimentology of a Lower Ordovician limestone sequence at Hälludden, Öland, Sweden. Geologiska Föreningens i Stockholm Förhandlingar, 111:65–94.CrossRefGoogle Scholar
Purnell, M. A., and Donoghue, P. C. J. 1998. Architecture and functional morphology of the skeletal apparatus of ozarkodinid conodonts. Palaeontology, 41:57–102.Google Scholar
Purnell, M. A., Donoghue, P. C. J., and Aldridge, R. J. 2000. Orientation and anatomical notation in conodonts. Journal of Paleontology, 74:113–122.2.0.CO;2>CrossRefGoogle Scholar
Rasmussen, J. A. 1991. Conodont stratigraphy of the Lower Ordovician Huk Formation at Slemmestad, southern Norway. Norsk Geologisk Tidsskrift, 71:265–88, 8 text-figs., 1 appendix.Google Scholar
Rasmussen, J. A. 2001. Conodont biostratigraphy and taxonomy of the Ordovician shelf margin deposits in the Scandinavian Caledonides. Fossils and Strata, 48:1–180.Google Scholar
Sarmiento, G. N. 1990. Conodontos ordovícicos de Argentina. Treballs del Museu de Geologia de Barcelona, 1:135–161.Google Scholar
Sergeeva, S. P. 1963. Konodontij iz niznego ordovika Leningradskoj oblasti. [Conodonts from the Lower Ordovician in the Leningrad region]. Akademia Nauk SSSR. Paleontologicheskij Zhurnal, 1963:93–108. Moskva. (In Russian)Google Scholar
Stouge, S. 1984. Conodonts of the Middle Ordovician Table Head Formation, western Newfoundland. Fossils and Strata, 16:1–145.Google Scholar
Stouge, S., and Bagnoli, G. 1990. Lower Ordovician (Volkhovian-Kundan) conodonts from Hagudden, northern Öland, Sweden. Palaeontographia Italica, 77:1–54. Pisa.Google Scholar
Stouge, S., and Bagnoli, G. 1999. The suprageneric classification of some Ordovician prioniodontid conodonts. Bolletino della Società Paleontologica Italiana, 37:145–158.Google Scholar
Sweet, W. C. 1981. Macromorphology of elements and apparatuses, p. W5–W20. In Robinson, R. A. (ed.), Treatise on Invertebrate Paleontology, Pt. W, Miscellanea, Supplement 2, Conodonta. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Sweet, W. C. 1988. The Conodonta: Morphology, Taxonomy, Palaeoecology, and Evolutionary History of a Long-extinct Animal Phylum. Clarendon Press, Oxford, 212 p.Google Scholar
Sweet, W. C., and Donoghue, P. C. J. 2001. Conodonts: Past, present, future. Journal of Paleontology, 75:1174–1184.CrossRefGoogle Scholar
Thorslund, P., and Jaanusson, V. 1960. The Cambrian, Ordovician and Silurian in Västergötland, Närke, Dalarna, and Jämtland, central Sweden. Guide to excursions Nos. A23 and C18. International geological Congress, 21 Session, Norden 1960, Sweden, Guide-book e: 1–51, Stockholm.Google Scholar
Tolmacheva, T. J. 2001. Conodont biostratigraphy and diversity in the Lower-Middle Ordovician of eastern Baltoscandia (St. Petersburg region, Russia) and Kazakhstan. Ph.D. thesis, Department of Earth Sciences, Historical Geology and Palaeontology, Uppsala University, 40 p., 8 pls.Google Scholar
Tolmacheva, T., Egerquist, E., Meidla, T., and Holmer, L. 2001. Spatial variations in faunal composition, Middle Ordovician, Volkhov Stage, East Baltic. GFF, 123:65–72.CrossRefGoogle Scholar
Tolmacheva, T., and Löfgren, A. 2000. Morphology and paleogeography of the Ordovician conodont Paracordylodus gracilis Lindström, 1955: comparison of two populations. Journal of Paleontology, 74:1114–1121.CrossRefGoogle Scholar
Tolmacheva, T. Y., and Purnell, M. A. 2002. Apparatus composition, growth, and survivorship of the Lower Ordovician conodont Paracordylodus gracilis Lindström. Palaeontology, 45:209–228.CrossRefGoogle Scholar
Viira, V. 1972. On symmetry of some Middle Ordovician conodonts. Geologica et Palaeontologica, 6:45–49.Google Scholar
Viira, V. 1974. Konodonty Ordovika Pribaltiki (Ordovician conodonts of the east Baltic). “Valgus”, Tallinn, 142 p.Google Scholar
Viira, V., Löfgren, A., Mägi, S., and Wickström, J. 2001. An Early to Middle Ordovician succession of conodont faunas at Mäekalda, northern Estonia. Geological Magazine, 138:699–718.CrossRefGoogle Scholar
Chengyuan, Wang, and Bergström, S. M. 1995. Castlemainian (Late Yushanian) to Darriwilian (Zhejiangian) conodont faunas. In Chen, Xu and Bergström, S. M., (eds.), The Base of the austrodentatus Zone as a level for global subdivision of the Ordovician System. Palaeoworld, 5:86–91.Google Scholar
Chengyuan, Wang, and Bergström, S. M. 1999. Conodont–graptolite biostratigraphic relations across the base of the Darriwilian Stage (Middle Ordovician) in the Yangtze Platform and the JCY area in Zhejiang, China. Bolletino della Società Paleontologica Italiana, 37:187–198.Google Scholar
Chengyuan, Wang, Bergström, S. M., and Lane, H. R. 1996. Conodont provinces and biostratigraphy in Ordovician of China. Acta Palaeontologica Sinica, 35:26–59.Google Scholar
Jianhua, Zhang. 1997. The Lower Ordovician conodont Eoplacognathus crassus Chen & Zhang, 1993. GFF, 119:61–65.CrossRefGoogle Scholar
Jianhua, Zhang. 1998a. Middle Ordovician conodonts from the Atlantic Faunal Region and the evolution of key conodont genera. Meddelanden från Stockholms Universitets institution för geologi och geokemi, 298:5–27. Stockholm.Google Scholar
Jianhua, Zhang. 1998b. Conodonts from the Guniutan Formation (Llanvirnian) in Hubei and Hunan Provinces, south-central China. Stockholm Contributions in Geology, 46:1–161.Google Scholar
Jianhua, Zhang. 1999. Review of the Ordovician conodont zonal index Eoplacognathus suecicus Bergström, 1971. Journal of Paleontology, 73:487–493.CrossRefGoogle Scholar