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Stratigraphic and Paleogeographic Significance of An Upper Ordovician Acritarch Flora from the Maquoketa Shale, Northeastern Missouri, U.S.A.

Published online by Cambridge University Press:  11 August 2017

Reed Wicander ,
Geoffrey Playford  and
Eddie B. Robertson
Reed Wicander
Affiliation:
Department of Geology, Central Michigan University, Mount Pleasant 48859
Geoffrey Playford
Affiliation:
Department of Earth Sciences, The University of Queensland, Brisbane, Australia 4072
Eddie B. Robertson
Affiliation:
Reinhardt College, Waleska, Georgia 30183
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Abstract

A well-preserved and moderately diverse acritarch assemblage was recovered from the upper Ordovician Maquoketa Shale of northeastern Missouri. Based on graptolite and conodont evidence, the Maquoketa in northeastern Missouri is considered Richmondian (=Ashgill) in age.

The acritarch assemblage comprises 28 species, distributed among 17 genera including two new genera, Caelatosphaera and Stictosoma. There are 11 new species, Baltisphaeridium adiastaltum, Caelatosphaera verminosa (type species), Dorsennidium undosum, Elektoriskos aktinotos, Lophosphaeridium acinatum, L. varum, Micrhystridium hirticulum, M. prolixum, Peteinosphaeridium accinctulum, P. septuosum, and Stictosoma gemmata (type species); together with two species similar to previously named species and three species left in open nomenclature. Cosmopolitan and stratigraphically important species identified include Baltisphaeridium perclarum Loeblich and Tappan, 1978; Cheleutochroa sp. cf. C. diaphorosa Turner, 1984; Dorsennidium hamii (Loeblich, 1970) Sarjeant and Stancliffe, 1994; Excultibrachium concinnum Loeblich and Tappan, 1978; Orthosphaeridium insculptum Loeblich, 1970; O. rectangulare (Eisenack, 1963) Eisenack, 1968, and Villosacapsula setosapellicula (Loeblich, 1970) Loeblich and Tappan, 1976. Polygonium gracile Vavrdová, 1966 emend. Sarjeant and Stancliffe, 1994 and Micrhystridium hirticulum new species dominate the assemblage, followed by Dorsennidium undosum new species, Baltisphaeridium oligopsakium Loeblich and Tappan, 1978, Veryhachium sp. cf. V. oklahomense Loeblich, 1970, Peteinosphaeridium accinctulum new species, and Lophosphaeridium acinatum new species. Additionally, the palynoflora contains chitinozoans, scolecodonts, cryptospores, and the enigmatic palynomorph Gloeocapsomorpha prisca Zalessky, 1917 emend. Foster, Reed, and Wicander, 1989.

Paleontologic-palynologic and sedimentologic evidence indicates that the Maquoketa Shale at the two studied localities accumulated under low energy, somewhat offshore, and unrestricted marine conditions. The present Maquoketa Shale acritarch palynoflora shows greatest similarity to those of the Sylvan Shale (Ashgill; Richmondian) of Oklahoma and the Maquoketa Shale (Caradoc and Ashgill) of Kansas. Whereas there are some cosmopolitan acritarch species present in the Maquoketa Shale, its palynoflora shows no pronounced similarity with age-equivalent acritarch suites from outside of North America.

Type
Research Article
Information
Journal of Paleontology , Volume 73 , Issue S51: Paleontological Society Memoir 51. Stratigraphic and paleogeographic significance of an upper Ordovician acritarch flora from the Maquoketa Shale, northeastern Missouri, U.S.A. , November 1999 , pp. 1 - 38
Copyright
Copyright © 1999, The Paleontological Society 

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References

Al-Ameri, T. K. 1983. Acid-resistant microfossils used in the determination of Palaeozoic palaeoenvironments in Libya. Palaeogeography, Palaeoclimatology, Palaeoecology, 44:103–116.Google Scholar
Amsden, T. W. 1974. Late Ordovician and Early Silurian articulate brachiopods from Oklahoma, southwestern Illinois, and eastern Missouri. Oklahoma Geoogical Survey Bulletin, 119:1–154.Google Scholar
Amsden, T. W. 1986. Part 1—Paleoenvironment of the Keel-Edgewood oolitic province and the Hirnantian strata of Europe, U.S.S.R., and China, p. 1–55. In Amsden, T. W. and Barrick, J. E. (eds.), Late Ordovician-Early Silurian Strata in the Central United States and the Hirnantian Stage. Oklahoma Geological Survey Bulletin, 139.Google Scholar
Barrick, J. E. 1986. Part 2—Conodont faunas of the Keel and Cason Formations, p. 57–95. In Amsden, T. W. and Barrick, J. E. (eds.), Late Ordovician-Early Silurian Strata in the Central United States and the Hirnantian Stage. Oklahoma Geological Survey Bulletin, 139.Google Scholar
Bergström, S. M. 1986. Biostratigraphic integration of Ordovician graptolite and conodont zones—a regional review, p. 61–78. In Hughes, C. P. and Rickards, R. B. (eds.), Palaeoecology and Biostratigraphy of Graptolites. Geological Society Special Publication No. 20.Google Scholar
Bergström, S. M., and Mitchell, C. E. 1992. The Ordovician Utica Shale in the eastern Midcontinent region: age, lithofacies, and regional relationships. Oklahoma Geological Survey Bulletin, 145:67–89.Google Scholar
Berry, W. N. B., and Marshall, F. C. 1971. Late Ordovician graptolites from the Maquoketa Formation in eastern Missouri. Journal of Paleontology, 45:253–257.Google Scholar
Burmann, G. 1970. Weitere organische Mikrofossilien aus dem unteren Ordovizium. Paläontologische Abhandlungen, Abteilung B, 3:289–332.Google Scholar
Colbath, G. K. 1979. Organic-walled microphytoplankton from the Eden Shale (upper Ordovician). Indiana, U.S.A. Palaeontographica, Abteilung B, 171:1–38.Google Scholar
Colbath, G. K. 1980. Abundance fluctuations in upper Ordovician organic-walled microplankton from Indiana. Micropaleontology, 26:97–102.Google Scholar
Colbath, G. K. 1990. Devonian (Givetian-Frasnian) organic-walled phytoplankton from the Limestone Billy Hills Reef Complex, Canning Basin, Western Australia. Palaeontographica, Abteilung B, 217:87–145.Google Scholar
Cramer, F. H. 1964. Microplankton from three Palaeozoic formations in the province of León, NW-Spain. Leidse Geologische Mededelingen, 30:253–361.Google Scholar
Cramer, F. H. 1971. Distribution of selected Silurian acritarchs. An account of the palynostratigraphy and paleogeography of selected Silurian acritarchs. Revista Española de Micropaleontologia, número extraordinario, 1:1–203. (imprinted 1970, issued 1971 vide Loeblich and Tappan, 1976, p. 302).Google Scholar
Deflandre, G. 1937. Microfossiles des silex crétacés. Deuxième partie. Flagellés incertae sedis Hystrichosphaeridés. Sarcodinés. Organismes divers. Annales de Paléontologie, 26:51–103.Google Scholar
Deunff, J. 1951. Sur la présence de microorganismes (Hystrichosphères) dans les schistes Ordoviciens du Finistére. Compte Rendu de l'Académie des Sciences de Paris, série D, 233:321–323.Google Scholar
Deunff, J. 1954. Veryhachium, genre nouveau d'Hystrichosphères du Primaire. Compte Rendu sommaire de la Société géologique de France, 13:305–306.Google Scholar
Deunff, J. 1959. Microorganismes planctoniques du Primaire armoricain I. Ordovicien du Veryhac'h (Presqu' île de Crozon). Bulletin de la Société géologique et minéralogique de Bretagne, nouvelle série, 14:1–41.Google Scholar
Deunff, J., and Massa, D. 1975. Palynologie et stratigraphic du Cambro-Ordovicien (Libye nord-occidentale). Comptes Rendus de l'Académie des Sciences de Paris, série D, 281:21–24.Google Scholar
Dorning, K. J. 1981. Silurian acritarch distribution in the Ludlovian Shelf Sea of South Wales and the Welsh Borderland, p. 31–36. In Neale, R. G. and Brasier, M. D. (eds.), Microfossils from Recent and Fossil Shelf Seas, Chapter 3. Ellis Horwood Ltd., Chichester.Google Scholar
Downie, C. 1958. An assemblage of microplankton from the Shineton Shales (Tremadocian). Proceedings of the Yorkshire Geological Society, 31:331–349.Google Scholar
Downie, C. 1959. Hystrichospheres from the Silurian Wenlock Shale of England. Palaeontology, 2:56–71.Google Scholar
Downie, C. 1963. “Hystrichospheres” (acritarchs) and spores of the Wenlock Shales (Silurian) of Wenlock, England. Palaeontology, 6:625–652.Google Scholar
Duffield, S. L., and Legault, J. A. 1981. Acritarch biostratigraphy of upper Ordovician-Lower Silurian rocks, Anticosti Island, Québec: preliminary results, p. 91–99. In Lespérance, P. J. (ed.), Subcommission on Silurian Stratigraphy, Ordovician-Silurian Boundary Working Group. Field Meeting, Anticosti-Gaspé, Québec, 1981, Volume II, Stratigraphy and Paleontology.Google Scholar
Eisenack, A. 1931. Neue Mikrofossilien des baltischen Silurs. 1. Paläontologische Zeitschrift, 13:74–118.Google Scholar
Eisenack, A. 1938. Hystrichosphaerideen und verwandte Formen im baltischen Silur. Zeitschrift für Geschiebeforschung und Flachlandsgeologie, 14:1–30.Google Scholar
Eisenack, A. 1951. Über Hystrichosphaerideen und andere Kleinformen aus baltischem Silur und Kambrium. Senckenbergiana Lethaea, 32:187–204.Google Scholar
Eisenack, A. 1955. Chitinozoen, Hystrichosphären und andere Mikrofossilien aus dem Beyrichia-Kalk. Senckenbergiana Lethaea, 36:157–188.Google Scholar
Eisenack, A. 1958. Mikroplankton aus dem norddeutschen Apt nebst einigen Bemerkungen über fossile Dinoflagellaten. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 106:383–422.Google Scholar
Eisenack, A. 1958. Tasmanites Newton 1875 und Leiosphaeridia n. g. als Gattungen der Hystrichosphaeridea. Palaeontographica, Abteilung A, 110:1–19.Google Scholar
Eisenack, A. 1959. Neotypen baltischer Silur-Hystrichosphären und neue Arten. Palaeontographica, Abteilung A, 112:193–211.Google Scholar
Eisenack, A. 1963. Mitteilungen zur Biologie der Hystrichosphären und über neue Arten. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 118:207–216.Google Scholar
Eisenack, A. 1965. Die Mikrofauna der Ostseekalke. 1. Chitinozoen, Hystrichosphären. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 123:115–148.Google Scholar
Eisenack, A. 1968. Mikrofossilien eines Geschiebes der Borkholmer Stufe, baltisches Ordovizium, F2. Mitteilungen aus dem Geologischen Staatsinstitut in Hamburg, 37:81–94.Google Scholar
Eisenack, A. 1969. Zur Systematik einiger paläozoischer Hystrichosphären (Acritarcha) des baltischen Gebietes. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 133:245–266.Google Scholar
Eisenack, A., Cramer, F. H., and Díez, M. del C. R. 1976. Katalog der fossilen Dinoflagellaten, Hystrichosphären und verwandten Mikrofossilien. Band IV Acritarcha 2. Teil. E. Schweizertbart'sche Verlagsbuchhandlung, Stuttgart, 863 p.Google Scholar
Eiserhardt, K. H. 1984. Carinatosphaeridium n. g. (Acritarcha) aus einem Öjlemyr-Flintgeschiebe Gotlands (ob. Ordovizischer). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, 1984(9):521–528.CrossRefGoogle Scholar
Eiserhardt, K. H. 1985. Orthosphaeridium rectangulare (Eisenack, 1963) (Acritarcha) aus einem Öjlemyrflint-Geschiebe (Schweden). Mitteilungen des Geologischen und Paläontologischen Institut der Universität, Hamburg, 59:137–154.Google Scholar
Eiserhardt, K. H. 1986. Palaeohystrichosphaeridium wimani (Eisenack, 1968) n. g.—ein ordovizischer Dinoflagellat? Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, 1986(3):175–191.Google Scholar
Eiserhardt, K. H. 1987. Das Acritarch Goniosphaeridium polygonale subsp. robustum n. ssp. aus Öjlemyrflint-Geschiebe. Geschiebekunde Aktuell, 3(2):31–33.Google Scholar
Eiserhardt, K. H. 1989. Baltisphären aus Gotländer Öjlemyrflint (Acritarcha, Oberordoviz Geschiebe, Schweden). Mitteilungen des Geologischen und Paläontologischen Institut der Universität, Hamburg, 68:79–129.Google Scholar
Eiserhardt, K. H. 1991a. Sphaeromorphe Zysten und Phycomata aus Öjlemyrflint-Geschieben (Oberordoviz, Gotland/Schweden) Teil 1. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, 1991(7):381–401.Google Scholar
Eiserhardt, K. H. 1991b. Sphaeromorphe Zysten und Phycomata aus Öjlemyrflint-Geschieben (Oberordoviz, Gotland/Schweden) Teil 2. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, 1991(10):579–596.CrossRefGoogle Scholar
Eiserhardt, K. H. 1992. Die Acritarcha des Öjlemyrflintes. Palaeontographica, Abteilung B, 226:1–132.Google Scholar
Elaouad-Debbaj, Z. 1981. Acritarches de 1'Ordovicien supérieur du Synclinal de Buçaco (Portugal). Systématique-biostratigraphie-intérêt paléogéographique. Bulletin de la Société Géologique et Minéralogique de Bretagne, série C, 3:83–88.Google Scholar
Elaouad-Debbaj, Z. 1988. Acritarches de l'Ordovicien supérieur (Caradoc-Ashgill) de l'Anti-Atlas, Maroc. Revue de Micropaléontologie, 30:232–248.Google Scholar
Evitt, W. R. 1963. A discussion and proposals concerning fossil dinoflagellates, hystrichospheres and acritarchs, I, II. Proceedings of the National Academy of Sciences, 49:158–164, 298–302.Google Scholar
Fensome, R. A., Williams, G. L., Barss, M. S., Freeman, J. M., and Hill, J. M. 1990. Acritarchs and fossil prasniophytes: an index to genera, species and infraspecific taxa. American Association of Stratigraphic Palynologists, Contributions Series, 25:771 p.Google Scholar
Fortey, R. A., Harper, D. A. T., Ingham, J. K., Owen, A. W., and Rushton, A. W. A. 1995. A revision of Ordovician series and stages from the historical type area. Geological Magazine, 132:15–30.Google Scholar
Foster, C. B., Reed, J. D., and Wicander, R. 1989. Gloeocapsomorpha prisca Zalessky, 1917: a new study part I: taxonomy, geochemistry, and paleoecology. Geobios, 22:735–759.Google Scholar
Goldman, D., and Bergström, S. M. 1997. Late Ordovician graptolites from the North American Midcontinent. Palaeontology, 40:965–1010.Google Scholar
Goldman, D., Bergström., S. M., and Mitchell, C. E. 1995. Revision of the Zone 13 graptolite biostratigraphy in the Marathon, Texas standard succession and its bearing on upper Ordovician graptolite biogeography. Lethaia, 28:115–128.Google Scholar
Górka, H. 1969. Microorganismes de l'Ordovicien de Pologne. Palaeontologia Polonica, 22:1–102.Google Scholar
Górka, H. 1979. Les Acritarches de l'Ordovicien moyen d'Oltsztyn IG2 (Pologne). Acta Palaeontologica Polonica, 24:351–376.Google Scholar
Górka, H. 1987. Acritarches et Prasinophyceae de l'Ordovicien moyen (Viruen) de Sondage de Smedsby Gård No. 1 (Gotland, Suède). Review of Palaeobotany and Palynology, 52:257–297.Google Scholar
Gray, J., and Boucot, A. J. 1972. Palynological evidence bearing on the Ordovician-Silurian paraconformity in Ohio. Geological Society of America Bulletin, 85:1299–1314.Google Scholar
Greuter, W., Barrie, F. R., Burdet, H. M., Chaloner, W. G., Demoulin, V., Hawksworth, D. L., Jørgensen, P. M., McNeill, J., Nicolson, D. H., Silva, P. C., and Trehane, P. 1994. International Code of Botanical Nomenclature (Tokyo Code). Regnum Vegetabile, 131. Koeltz Scientific Books, Königstein, 389 p.Google Scholar
Hedlund, R. W. 1960. Microfossils of the Sylvan Shale (Ordovician) of Oklahoma. , University of Oklahoma, Norman, 89 p.Google Scholar
Hill, P. J., and Molyneux, S. G. 1988. Biostratigraphy, palynofacies and provincialism of late Ordovician-Early Silurian acritarchs from northeast Libya, p. 27–43. In El-Arnauti, A., Owens, B., and Thusu, B. (eds.), Subsurface Palynostratigraphy of Northeast Libya. Garyounis University Publications, Benghazi.Google Scholar
Jacobson, S. R. 1978. Acritarchs from the upper Ordovician Clays Ferry Formation, Kentucky. U.S.A. Palinología, Número Extraordinario, 1:293–301.Google Scholar
Jacobson, S. R. 1979. Acritarchs as paleoenvironmental indicators in middle and upper Ordovician rocks from Kentucky, Ohio, and New York. Journal of Paleontology, 53:1197–1212.Google Scholar
Jacobson, S. R. 1987. ‘Middle Ordovician’ acritarchs are guide fossils for the upper Ordovician. Lethaia, 20:91–92.Google Scholar
Jacobson, S. R., and Achab, A. 1985. Acritarch biostratigraphy of the Dicellograptus complanatus graptolite Zone from the Vaureal Formation (Ashgillian), Anticosti Island, Quebec, Canada. Palynology, 9:165–198.Google Scholar
Jardiné, S., Combaz, A., Magloire, L., Peniguel, G., and Vachey, G. 1974. Distribution stratigraphique des acritarches dans le Paléozoïque du Sahara algérien. Review of Palaeobotany and Palynology, 18:99–129.Google Scholar
Jenkins, W. A. M. 1984. Ordovician rocks in the Eastcan et al. Freydis B-87 and other wells in offshore Atlantic Canada. Canadian Journal of Earth Sciences, 21:864–868.Google Scholar
Kalvacheva, R., and Chobanova, A. 1973. Statistical analysis on several species of the genus Veryhachium (Acritarcha) from the Ordovician in the Iskur Gorge (Bulgaria). Bulgarian Academy of Sciences, Bulletin of the Geological Institute, Series Paleontology, 22:5–20. (In Bulgarian with English summary).Google Scholar
Keegan, J. B., Rasul, S. M., and Shaheen, Y. 1990. Palynostratigraphy of the Lower Palaeozoic, Cambrian to Silurian, sediments of the Hashemite Kingdom of Jordan. Review of Palaeobotany and Palynology, 66:167–180.CrossRefGoogle Scholar
Keenan, J. E. 1951. Ostracodes from the Maquoketa Shale of Missouri. Journal of Paleontology, 25:561–574.Google Scholar
Kjellström, G. 1971a. Ordovician microplankton (baltisphaerids) from the Grötlingbo Borehole No. 1 in Gotland, Sweden. Sveriges Geologiska Undersökning, series C, no. 655, 65(1):1–75.Google Scholar
Kjellström, G. 1971b. Middle Ordovician microplankton from the Grötlingbo Borehole No. 1 in Gotland, Sweden. Sveriges Geologiska Undersökning, series C, no. 669, 65(15):1–35.Google Scholar
Kjellström, G. 1976. Lower Viruan (middle Ordovician) microplankton from the Ekön borehole No. 1 in Östergötland, Sweden. Sveriges Geologiska Undersökning, series C, no. 724, 70(6):1–44.Google Scholar
Koenig, J. W., Martin, J. A., and Collinson, C. W. 1961. Guidebook twenty-sixth regional field conference, northeastern Missouri and west-central Illinois. Kansas Geological Society Report of Investigations, 27, 168 p.Google Scholar
Konzalová-Manzanková, M. 1969. Acritarcha Evitt 1963 aus dem Unter-Ashgill Böhmens. Palaeontographica, Abteilung B, 165:81–92.Google Scholar
Legault, J. A. 1982. First report of Ordovician (Caradoc-Ashgill) palynomorphs from Orphan Knoll, Labrador Sea. Canadian Journal of Earth Sciences, 19:1851–1856.Google Scholar
Jun, Li. 1995. Ordovician (Caradoc) acritarchs from Qilang Formation of Kalpin, Xinjiang, China. Acta Palaeontologica Sinica, 34:454–467.Google Scholar
Jun, Li, and Yi, Wang. 1997. Ordovician acritarchs from boreholes in the Tarim Basin. Acta Micropalaeontologica Sinica, 14:175–190.Google Scholar
Loeblich, A. R. Jr. 1970a. Morphology, ultrastructure and distribution of Paleozoic acritarchs. Proceedings of the North American Paleontological Convention, Chicago, 1969, Pt. G:705–788.Google Scholar
Loeblich, A. R. Jr. 1970b. Dicommopalla, a new acritarch genus from the Dillsboro Formation (upper Ordovician) of Indiana. U.S.A. Phycologia, 9:39–43.Google Scholar
Loeblich, A. R. Jr., and MacAdam, R. B. 1971. North American species of the Ordovician acritarch genus Aremoricanium . Palaeontographica, Abteilung B, 135:41–47.Google Scholar
Loeblich, A. R. Jr., and Tappan, H. 1971. Two new Orthosphaeridium (Acritarcha) from the middle and upper Ordovician. Transactions of the American Microscopy Society, 90:182–188.Google Scholar
Loeblich, A. R., and Tappan, H. 1976. Some new and revised organic-walled phytoplankton microfossil genera. Journal of Paleontology, 50:301–308.Google Scholar
Loeblich, A. R., and Tappan, H. 1978. Some middle and late Ordovician microplankton from central North America. Journal of Paleontology, 52:1233–1287.Google Scholar
Martin, F. 1966. Les acritarches de Sart-Bernard (Ordovicien belge). Bulletin de la Société belge de Géologie, de Paléontologie et d'Hydrologie, 74:423–444.Google Scholar
Martin, F. 1969. Les acritarches de l'Ordovicien et du Silurien belges. Détermination et valeur stratigraphique. Mémoire de l'Institut royal des Sciences naturelles de Belgique, 160, 175 p. (imprinted 1968, issued 1969).Google Scholar
Martin, F. 1974. Ordovicien supérieur et Silurien inférieur à Deerlijk (Belgique). Mémoire de l'Institut royal Sciences naturelles de Belgique, 174, 71 p. (imprinted 1973, issued 1974).Google Scholar
Martin, F. 1980. Quelques chitinozoaires et acritarches ordoviciens supérieurs de la formation de White Head en Gaspésie, Québec. Canadian Journal of Earth Sciences, 17:106–117.Google Scholar
Martin, F. 1983. Chitinozoaires et acritarches ordoviciens de la plate-forme du Saint-Laurent (Québec et sud-est de l'Ontario). Geological Survey of Canada Bulletin, 310:1–59.Google Scholar
Martin, F. 1988. Late Ordovician and Early Silurian acritarchs, p. 299–309. In Cocks, L. R. M. and Rickards, R. B. (eds.), A Global Analysis of the Ordovician-Silurian Boundary. Bulletin of the British Museum (Natural History), Geology Series, 43.Google Scholar
Martin, J. A., Knight, R. D., and Hayes, W. C. 1961. Ordovician system, p. 20–32. In Koenig, J. W. (ed.), The Stratigraphic Succession in Missouri. Missouri Geological Survey and Water Resources, XL (second series).Google Scholar
McCracken, A. D., and Barnes, C. R. 1981. Conodont biostratigraphy and paleoecology of the Ellis Bay Formation, Anticosti Island, Quebec, with special reference to late Ordovician-Early Silurian chronostratigraphy and the systemic boundary. Geological Survey of Canada Bulletin, 329:51–134.Google Scholar
McCracken, A. D., and Barnes, C. R. 1982. Restudy of conodonts (late Ordovician-Early Silurian) from the Edgewood Group, Clarksville, Missouri. Canadian Journal of Earth Sciences, 19:1474–1485.Google Scholar
Mendelson, C. V. 1981. Studies in micropaleontology: Proterozoic microfossils, Ordovician microphytoplankton, and Recent agglutinated Foraminifera. Unpublished Ph.D. dissertation, University of California at Los Angeles, Los Angeles, 241 p.Google Scholar
Miller, M. A. 1991. Paniculaferum missouriensis gen. et sp. nov., a new upper Ordovician acritarch from Missouri, U.S.A. Review of Palaeobotany and Palynology, 70:217–223.Google Scholar
Molyneux, S. G. 1988. Late Ordovician acritarchs from northeast Libya, p. 45–59. In El-Arnauti, A., Owens, B., and Thusu, B. (eds.), Subsurface Palynostratigraphy of Northeast Libya. Garyounis University Publications, Benghazi.Google Scholar
Molyneux, S. G., and Paris, F. 1985. Late Ordovician palynomorphs, p. 11–26. In Thusu, B. and Owens, B. (eds.), Palynostratigraphy of northeast Libya. Journal of Micropalaeontology, 4.Google Scholar
Molyneux, S. G., Le Hérissé, A., and Wicander, R. 1996. Chapter 16. Paleozoic phytoplankton, p. 493–529. In Jansonius, J. and McGregor, D. C. (eds.), Palynology: Principles and Applications, Volume 2. American Association of Stratigraphic Palynologists Foundation.Google Scholar
Playford, G., and Dring, R. S. 1981. Late Devonian acritarchs from the Carnarvon Basin, Western Australia. Special Papers in Palaeontology, 27, 78 p.Google Scholar
Playford, G., and Wicander, R. 1988. Acritarch palynoflora of the Coolibah Formation (lower Ordovician), Georgina Basin, Queensland, p. 5–40. In Jell, P. A. and Playford, G. (eds.), Palynological and Palaeobotanical Studies in Honour of Basil E. Balme. Association of Australasian Palaeontologists Memoir, 5.Google Scholar
Playford, G., Ribecai, C., and Tongiorgi, M. 1995. Ordovician acritarch genera Peteinosphaeridium, Liliosphaeridium, and Cycloposphaeridium: morphology, taxonomy, biostratigraphy, and palaeogeographic significance. Bollettino della Società Paleontologica Italiana, 34:3–54.Google Scholar
Richardson, J. B., and Rasul, S. M. 1990. Palynofacies in a Late Silurian regressive sequence in the Welsh Borderland and Wales. Journal of the Geological Society, London, 147:675–686.Google Scholar
Riegel, W. 1974. Phytoplankton from the Upper Emsian and Eifelian of the Rhineland, Germany—a preliminary report. Review of Paleobotany and Palynology, 18:29–39.Google Scholar
Robertson, E. B. 1997. Fossil microplankton from the upper Ordovician Maquoketa Formation exposed in Pike County, Missouri. Georgia Journal of Science, 55:76.Google Scholar
Sarjeant, W. A. S., and Stancliffe, R. P. W. 1994. The Micrhystridium and Veryhachium complexes (Acritarcha: Acanthomorphitae and Polygonomorphitae): a taxonomic reconsideration. Micropaleontology, 40:1–77.Google Scholar
Sarjeant, W. A. S., and Stancliffe, R. P. W. 1996. The acritarch genus Polygonium, Vavrdová emend Sarjeant and Stancliffe 1994: a reassessment of its constituent species. Annales de la Société géologique de Belgique, 117:355–369.Google Scholar
Scotese, C. R., and McKerrow, W. S. 1990. Revised world maps and introduction, p. 1–21. In McKerrow, W. S. and Scotese, C. R. (eds.), Palaeozoic Palaeogeography and Biogeography. Geological Society of London Memoir, 12.Google Scholar
Scotese, C. R., and McKerrow, W. S. 1991. Ordovician plate tectonic reconstructions, p. 283–298. In Barnes, C. R. and Williams, S. H. (eds.), Advances in Ordovician Geology. Geological Survey of Canada Paper, 90(9).Google Scholar
Servais, T. 1995. Paleobiogeography of Ordovician acritarchs: some general considerations, p. 457–460. In Cooper, J. D., Droser, M. L., and Finney, S. C. (eds.), Ordovician Odyssey: Short Papers for the Seventh International Symposium on the Ordovician System. The Pacific Section Society for Sedimentary Geology (SEPM), California.Google Scholar
Servais, T. 1996a. Some considerations on acritarch classification. Review of Palaeobotany and Palynology, 93:9–22.Google Scholar
Servais, T. 1996b. Acritarch distributions and their interpretation, an example: the Ordovician. Ninth International Palynological Congress program and abstracts: 145.Google Scholar
Servais, T. 1998. An annotated bibliographical review of Ordovician acritarchs. Annales de la Société géologique de la Belgique, 120:23–72. (imprinted 1997, issued 1998 vide Servais personal commun., May 1999).Google Scholar
Smith, N. D., and Saunders, R. S. 1970. Paleoenvironments and their control of acritarch distribution in the Silurian of east-central Pennsylvania. Journal of Sedimentary Petrology, 40:324–333.Google Scholar
Stancliffe, R. P. W., and Sarjeant, W. A. S. 1996. The acritarch genus Dorsennidium Wicander 1974, emend. Sarjeant and Stancliffe 1994: a reassessment of its constituent species. Micropaleontology, 42:151–166.Google Scholar
Staplin, F. L. 1961. Reef-controlled distribution of Devonian microplankton in Alberta. Palaeontology, 4:392–424.Google Scholar
Staplin, F. L., Jansonius, J., and Pocock, S. A. J. 1965. Evaluation of some acritarchous hystrichosphere genera. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 123:167–201.Google Scholar
Strother, P. K. 1996. Chapter 5. Acritarchs, p. 81–106. In Jansonius, J., and McGregor, D. C. (eds.), Palynology: Principles and Application, Volume 1. American Association of Stratigraphic Palynologists Foundation.Google Scholar
Sweet, W. C. 1988. The Conodonta: morphology, taxonomy, paleoecology, and evolutionary history of a long-extinct animal phylum. Oxford Monographs on Geology and Geophysics, 10, 212 p.Google Scholar
Tappan, H., and Loeblich, A. R. Jr. 1971. Surface sculpture of the wall in lower Paleozoic acritarchs. Micropaleontology, 17:385–410.Google Scholar
Thompson, T. L., and Satterfield, I. R. 1975. Stratigraphy and conodont biostratigraphy of strata contiguous to the Ordovician-Silurian boundary in eastern Missouri. Missouri Geological Survey Report of Investigation, 57:61–108.Google Scholar
Thusu, B. 1972. Depositional environments of the Rochester Formation (Middle Silurian) in southern Ontario. Journal of Sedimentary Petrology, 42:930–934.Google Scholar
Timofeev, B.V. 1959. The ancient flora of the Prebaltic region and its stratigraphic significance. Trudy VNIGRI, 129:1–319. (In Russian).Google Scholar
Tongiorgi, M., Lei-Ming, Yin, and Di Milia, A. 1995. Arenigian acritarchs from the Daping section (Yangtze Gorges area, Hubei province, southern China) and their palaeogeographic significance. Review of Palaeobotany and Palynology, 86:13–48.Google Scholar
Turner, R. E. 1984. Acritarchs from the type area of the Ordovician Caradoc series, Shropshire, England. Palaeontographica, Abteilung B, 190:87–157.Google Scholar
Umnova, N. I. 1975. Ordovician and Silurian Acritarchs of the Moscow Basin and the Prebaltic. Nedra, Moscow, 167 p. (In Russian).Google Scholar
Uutela, A., and Tynni, R. 1991. Ordovician acritarchs from the Rapla borehole, Estonia. Geological Survey of Finland Bulletin, 353:1–135.Google Scholar
Van Der Voo, R. 1988. Paleozoic paleogeography of North America, Gondwana and intervening displaced terranes: comparisons of paleomagnetism with paleoclimatology and biogeographical patterns. Geological Society of America Bulletin, 100:311–324.Google Scholar
Vavrdová, M. 1966. Palaeozoic microplankton from central Bohemia. Cbrasopis pro Mineralogii a Geologii, 11:409–414.Google Scholar
Vavrdová, M. 1974. Geographical differentiation of Ordovician acritarch assemblages in Europe. Review of Palaeobotany and Palynology, 18:171–175.Google Scholar
Vavrdová, M. 1982. Recycled acritarchs in the uppermost Ordovician of Bohemia. Cbrasopis pro Mineralogii a Geologii, 27:337–345.Google Scholar
Vavrdová, M. 1986. New genera of acritarchs from the Bohemian Ordovician. Casopis pro Mineralogii a Geologii, 31:349–359.Google Scholar
Vavrdová, M. 1988. Further acritarchs and terrestrial plant remains from the late Ordovician at Hlásná Treban (Czechoslovakia). Cbrasopis pro Mineralogii a Geologii, 33:1–10.Google Scholar
Vavrdová, M. 1989. New acritarchs and miospores from the late Ordovician of Hlásná Treban, Czechoslovakia. Cbrasopis pro Mineralogii a Geologii, 34:403–420.Google Scholar
Vecoli, M. 1996. Stratigraphic significance of acritarchs in Cambro-Ordovician boundary strata, Hassi-Rmel area, Algerian Sahara. Bollettino della Societá Paleontologica Italiana, 35:3–58.Google Scholar
Webby, B. D. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters on Stratigraphy, 36:1–33.Google Scholar
Werner, C., and Echols, D. J. 1958. Three-dimensional graptolites in the Maquoketa Shale (upper Ordovician). Journal of Paleontology, 32:1026–1029.Google Scholar
Wetzel, O. 1933. Die in organischer Substanz erhaltenen Mikrofossilien des baltischen Kreide-Feuersteins mit einem sediment-petrographischen und stratigraphischen Anhang. Palaeontographica, Abteilung A, 78:1–110.Google Scholar
Wicander, E. R. 1974. Upper Devonian-Lower Mississippian acritarchs and prasinophycean algae from Ohio, U.S.A. Palaeontographica, Abteilung B, 148:9–43.Google Scholar
Wicander, E. R., and Loeblich, A. R. Jr. 1977. Organic-walled microphytoplankton and its stratigraphic significance from the Upper Devonian Antrim Shale, Indiana, U.S.A. Palaeontographica, Abteilung B, 160:129–165.Google Scholar
Wicander, E. R., and Playford, G. 1985. Acritarchs and spores from the Upper Devonian Lime Creek Formation, Iowa, U.S.A. Micropaleontology, 31:97–138.Google Scholar
Wicander, E. R., and Wood, G. D. 1997. The use of microphytoplankton and chitinozoans for interpreting transgressive/regressive cycles in the Rapid Member of the Cedar Valley Formation (Middle Devonian), Iowa. Review of Palaeobotany and Palynology, 98:125–152.Google Scholar
Wicander, E. R., and Wright, R. P. 1983. Organic-walled microphytoplankton abundance and stratigraphic distribution from the Middle Devonian Columbus and Delaware Limestones of the Hamilton Quarry, Marion County, Ohio. Ohio Journal of Science, 83:2–13.Google Scholar
Wicander, E. R., Foster, C. B., and Reed, J. D. 1996. Chapter 7E. Gloeocapsomorpha , p. 215–225. In Jansonius, J., and McGregor, D. C. (eds.), Palynology: Principles and Applications, Volume 1. American Association of Stratigraphic Palynologists Foundation.Google Scholar
Wilde, P. 1991. Oceanography in the Ordovician, p. 283–298. In Barnes, C. R. and Williams, S. H. (eds.), Advances in Ordovician Geology. Geological Survey of Canada Paper 90(9).Google Scholar
Williams, G. L., Sarjeant, W. A. S., and Kidson, E. J. 1978. A glossary of the terminology applied to dinoflagellate amphiesmae and cysts and acritarchs. American Association of Stratigraphic Palynologists, Contributions Series, 2a:121 p.Google Scholar
Wright, R. P., and Meyers, W. C. 1981. Organic-walled microplankton in the subsurface Ordovician of northeastern Kansas. Kansas Geological Survey, Subsurface Geology Series, 4:53 p.Google Scholar
Zalessky, M. D. 1917. On marine sapropelite of Silurian age, formed by blue-green alga. Izvestiia Imperatorskoi Akademii Nauk (IV), 1:3–18. (In Russian).Google Scholar