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A revised chitinozoan classification

Published online by Cambridge University Press:  14 July 2015

Florentin Paris ,
Yngve Grahn ,
Viiu Nestor  and
Iskra Lakova
Florentin Paris
Affiliation:
Laboratoire de Paléontologie, UPR 4661 du CNRS, Université de Rennes I, 35042 Rennes-cedex, France
Yngve Grahn
Affiliation:
Universidade de Estato do Rio de Janeiro-UERJ, Faculdade de Geologia, 20559-900 Rio de Janeiro, Brazil
Viiu Nestor
Affiliation:
Tallinn Technical University, Institute of Geology, 7 Estonia Avenue, 10143 Tallinn, Estonia
Iskra Lakova
Affiliation:
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Abstract

The successful definition of chitinozoan genera depends primarily on the precision of the criteria used. A standardized morphological terminology based upon details from scanning electron microscope observations of the most representative taxa bearing these characters is therefore proposed. The 143 genera, or subgenera, described so far in the literature are reviewed in order to exclude invalid taxa and obvious junior synonyms. Particular attention is paid to preventing the overlap of generic definitions of the 56 genera ultimately retained. A brief account of the diagnostic features and stratigraphic range of selected genera is given, and basic information concerning the type material of these genera is listed. Finally, a suprageneric classification of the whole Chitinozoa group based on diagnostic features whose hierarchy is established on statistical and evolutionary grounds, is given. One new subfamily, Pogonochitininae, three new genera, Baltochitina, Hyalochitina, and Saharochitina, and a new species Baltochitina nolvaki, are defined. The subspecies Fungochitina fungiformis spinifera is elevated to a specific rank.

Type
Research Article
Information
Journal of Paleontology , Volume 73 , Issue 4 , July 1999 , pp. 549 - 570
Copyright
Copyright © The Paleontological Society 

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References

Achab, A. 1980. Chitinozoaires de l'Arenig inférieur de la Formation de Lévis (Québec, Canada). Review of Palaeobotany and Palynology, 31:219–239.CrossRefGoogle Scholar
Achab, A., Asselin, E., and Soufiane., A. 1993. New morphological characters observed in the Order Operculatifera and their implications for the suprageneric Chitinozoan classification. Palynology, 17:1–9.CrossRefGoogle Scholar
Al-Hajri, S., and Paris, F. 1998. Age and palaeoenvironment of the Sharawra Member (Silurian of North-western Saudi Arabia). Geobios, 31:3–12.CrossRefGoogle Scholar
Babin, C., Deunff, J., Melou, M., Paris, F., Pelhate, A., Plusquellec, Y., and Racheboeuf, P. R. 1979. La coupe de Porz Ar Vouden (Pridoli de la Presquile de Crozon) Massif Armoricain, France. Lithologie et Biostratigraphie. Palaeontographica A, 164:52–84.Google Scholar
Beju, D., and Danet., N. 1962. Chitinozoare Siluriene din Platforma moldoveneasca si Platforma moezica. Petrol si Gaze, 13:527–536.Google Scholar
Benoît, A., and Taugourgeau, P. 1961. Sur quelques Chitinozoaires del'Ordovicien du Sahara. Revue de l'Institut Français du Pétrole, 16:1403–1421.Google Scholar
Bockelie, T. G. 1981. Internal morphology of two species of Lagenochitina (Chitinozoa). Review of Palaeobotany and Palynology, 34:149–164.CrossRefGoogle Scholar
Bouché, P. M. 1965. Chitinozoaires du Silurien s.l. du Djado (Sahara nigérien). Revue de Micropaléontologie, 8(3):151–164.Google Scholar
Boumendjel, K. 1985. Nouvelles espéces de Chitinozoaires dans le Silurien et le Dévonien du Bassin d'Illizi (S.E. du Sahara algérien). Revue de Micropaléontologie, 28(3):155–166.Google Scholar
Cashman, P. B. 1990. The affinity of the Chitinozoans: new evidence. Modern Geology, 15:59–69.Google Scholar
Collinson, C., and Schwalb, H. 1955. North American Paleozoic Chitinozoa. Illinois State Geological Survey, Report of Investigation, 186, 33 p.Google Scholar
Collinson, C., and Scott, A. J. 1958. Chitinozoan-Faunule of the Devonian Cedar Valley Formation. Illinois State Geological Survey, 247, 34 p.Google Scholar
Combaz, A., and Poumot, C. 1962. Observations sur la structure des Chitinozoaires. Revue de Micropaleontologie, 5:147–160.Google Scholar
Combaz, A., Calandra, F., Jansonius, J., Millepied, P., Poumot, C., and Oyen, F. H. Van. 1967. Microfossiles organiques du Paléozoïque. Les Chitinozoaires (2): Morphographie. Éditions du Centre National de la Recherche Scientifique, Paris, 58 p.Google Scholar
CostaDa, N.M. Da, N.M. 1970. Pallachitina e Spathachitina, dois novos géneros de Quitinozoános do Siluriano Brasileiro. Anais Da Academia Brasileira De Ciéncias, 42:207–217.Google Scholar
Costa Cruz Da, N.M., and Quadros, L. P. 1985. Sommerochitina langei, umnovo fóssil guia do Devoniano superior da Bacia do Parna'bá. Coletinea de Trabalhos Paleontologicos, 7th Congresso Brasilieiro de Paleontólogia, Brasilia (1983), 1:289–293.Google Scholar
Cramer, F. H. 1964. Microplankton from three Paleozoic formations in the Province of Leon (NWSpain). Leidse Geologische Mededelingen, 30:255–361.Google Scholar
Cramer, F. H. 1966. Hoegispheres and other microfossils incertae sedis of the San Pedro Formation (Siluro-Devonian boundary) near Valporquero, Leon NW Spain. Notas y Comunicaciones del Instituto Geologico y Minero de Espana, 86:75–94.Google Scholar
Cramer, F. H. 1967. Chitinozoans of a composite section of Upper Llandoverian to basal Lower Gedinnian sediments in northern Leon, Spain. A preliminary report. Bulletin de la Société Beige de Géologie 75:69–129.Google Scholar
Cramer, F. H. 1969. Possible implications for Silurian paleogeography from phytoplankton assemblages of the Rose Hill and Tuscarora Formations of Pennsylvania. Journal of Paleontology, 43:485–491.Google Scholar
Dicevitchius, E. 1971. Some new species of Chitinozoa from Ordovician and Silurian deposits of the south Baltic and northwestern Byelorussia, 2, Sphaerochitina, p. 77–95. In Paleontology and Stratigraphy of Peribaltic and Byelorussia. Nauka, Moscow. (In Russian)Google Scholar
Dunn, D. L. 1959. Devonian Chitinozoans from the Cedar Valley Formation in Iowa. Journal of Paleontology, 33:1001–1017.Google Scholar
Dunn, D. L. and Miller, T. H. 1964. A distinctive chitinozoan faunule from the Alpena Limestone (Middle Devonian) of Michigan. Journal of Paleontology, 38:725–728.Google Scholar
Eisenack, A. 1931. Neue Mikrofossilien des baltischen Silurs 1. Palaeontologische Zeitschrift, 13:74–118.CrossRefGoogle Scholar
Eisenack, A. 1932. Neue Mikrofossilien des baltischen Silurs 2. Palaeontologische Zeitschrift, 14:257–277.CrossRefGoogle Scholar
Eisenack, A. 1934. Neue Mikrofossilien des baltischen Silurs 3 und neue Mikrofossilien des bohmischen silurs I. Palaeontologische Zeitschrift, 16:52–76.CrossRefGoogle Scholar
Eisenack, A. 1937. Neue Mikrofossilien des baltischen Silurs 4. Palaeontologische Zeitschrift, 19:217–243.CrossRefGoogle Scholar
Eisenack, A. 1939. Chitinozoen und Hystrichosphaerideen im Ordovizium des Rheinischen Schiefergebirges. Senckenbergiana, 21:135–152.Google Scholar
Eisenack, A. 1955a. Chitinozoen, Hystrichosphaeren und andere Mikrofossilien aus dem Beyrichia Kalk. Senckenbergiana lethaea, 36:157–188.Google Scholar
Eisenack, A. 1955b. Neue Chitinozoen aus dem Silur des Baltikums und dem Devon der Eifel. Senckenbergiana Lethaea, 36:311–319.Google Scholar
Eisenack, A. 1959. Neotypen baltischer Silur-Chitinozoen und neue Arten. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 108:1–20.Google Scholar
Eisenack, A. 1962. Neotypen baltischer Silur-Chitinozoen und neue Arten. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 114:291–316.Google Scholar
Eisenack, A. 1964. Mikrofossilien aus dem Silur Gotlands. Chitinozoen. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 120:308–342.Google Scholar
Eisenack, A. 1965. Die Mikrofauna der Ostseekalke. 1 Chitinozoen, Hystrichosphaeren. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 123:115–148.Google Scholar
Eisenack, A. 1968. Uber Chitinozoen des Baltischen Gebietes. Palaeontographica A, 131:137–198.Google Scholar
Eisenack, A. 1971. Weitere Mikrofossilien aus dem Beyrichienkalk (Silur). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, 8:449–460.Google Scholar
Eisenack, A. 1972. Beitrage zur chitinozoen forschung. Palaeontographica A, 140:117–130.Google Scholar
Febvay, G., and Bonnot, G. 1991. Un logiciel d'analyse multidimentionnelle sur Mac. Le Micro-Bulletin, Edition du Centre National de la Recherche Scientifique, 39:55–59.Google Scholar
Fortey, R. A., Harper, D. A. T., Ingham, K. J., Owen, A. W., and Rushton, A. W. A. 1995. A revision of Ordovician series and stages from the historical type area. Geological Magazine, 132:1–16.CrossRefGoogle Scholar
Geng, Liang-Yu, Ze-Shu, Quian, Liang-Sheng, Ding, Yue, Wang, Gen-Xian, Wang, and Xi-Yao, Cai. 1997. Silurian Chitinozoans from the Yangtze Region. Palaeoworld, 8:1–172.Google Scholar
Grahn, Y. 1981. Ordovician Chitinozoa from the Stora Åsbotorp boring in Västergötland south-central Sweden. Sveriges Geologiska Underssökning, Series C, 787, 40 p.Google Scholar
Grahn, Y. 1988. Chitinozoan stratigraphy in Ashgill and Llandovery. Bulletin of British Museum of Natural History (Geology), 43:317–323.Google Scholar
Grahn, Y. 1992. Revision of Silurian and Devonian strata of Brazil. Palynology, 16:35–61.CrossRefGoogle Scholar
Grahn, Y. and Paris, F. 1992. Age and correlation of the Trombetas Group, Amazonas Basin, Brazil. Revue de Micropaléontologie, 35:3–35.Google Scholar
Grahn, Y., J., Nõlvak, and Paris, F. 1996. Precise chitinozoan dating of Ordovician impact events in Baltoscandia. Journal of Micropalaeontology, 15:21–35.CrossRefGoogle Scholar
Grignani, D., and Mantovani, M. P. 1964. Les Chitinozoaires du sondage Oum Doul 1 (Maroc). Revue de Micropaléontologie, 6:243–259.Google Scholar
Jansonius, J. 1964. Morphology and classification of some Chitinozoa. Bulletin of Canadian Petroleum Geologists, 12:901–918.Google Scholar
Jansonius, J. 1967. Systematics of the Chitinozoa. Review of Palaeobotany and Palynology, 1:354–360.CrossRefGoogle Scholar
Jansonius, J. 1970. Classification and stratigraphic application of Chitinozoa. Proceedings of North American Paleontologists Convention (1969), G:786–808.Google Scholar
Jenkins, W. A. M. 1967. Ordovician Chitinozoa from Shropshire. Palaeontology, 10:436–488.Google Scholar
Jenkins, W. A. M. 1970a. Chitinozoa from the Ordovician Sylvan Shale of the Arbuckle Mountains, Oklahoma. Palaeontology, 13:261–288.Google Scholar
Jenkins, W. A. M. 1970b. Chitinozoa. Geoscience and Man, 1:1–21.CrossRefGoogle Scholar
Kozlowski, R. 1963. Sur la nature des Chitinozoaires. Acta Palaeontologica Polonica, 8:425–449.Google Scholar
Xiao-Juan, Lai. 1982. Chitinozoans from the Shujiaping Formation of the Lower Devonian in Tiekuangshan of Hezhang district, Guizou Province. Selected papers from: The first symposium of the Palynological Society of China (1979), 1:161–170.Google Scholar
Lakova, I. 1986. New Chitinozoan Taxa from the Gedinnian in Bulgaria. Review of Bulgarian Geological Society, 97:131–139.Google Scholar
Lange, F. W. 1949. Novos microfóssels devonianos do Paraná. Arquivos do Museu Paranaense, 7:287–298.Google Scholar
Lange, F. W. 1952. Chitinozoários do Folhelho Barreirinha, Devoniano do Pará. Dusenia, 3:373–386.Google Scholar
Lange, F. W. 1967. Biostratigraphic subdivision and correlation of the Devonian in the Parana Basin, p. 63–98. In Bigarella, J. J. (ed.), Problems in Brazilian Devonian Geology, Boletim Paranaense de Geociěncias, 21/22.Google Scholar
Laufeld, S. 1967. Caradocian Chitinozoan from Dalarna, Sweden. Geologiska Föreningens Stockholm Förhandlingar, 89:275–349.CrossRefGoogle Scholar
Laufeld, S. 1974. Silurian Chitinozoa from Gotland. Fossils and Strata, 51, 130 p.Google Scholar
LeGault, J. A. 1973a. Chitinozoa and Acritarcha of the Hamilton Formation (Middle Devonian), southwestern Ontario. Geological Survey of Canada, Bulletin, 221:1–103.Google Scholar
A.LeGault, J. LeGault, J. 1973b. Mode of aggregation of Hoegisphaera (Chitinozoa). Canadian Journal of Earth Sciences, 10:793–797.Google Scholar
Locquin, M. V. 1976. Les Chitinomycètes ou Chitinozoaires. Fossiles du Paléozoïque. Unpublished manuscript, De Taxia Fungorum, p. 5–8.Google Scholar
Locquin, M. V. 1985. Recherches récentes sur les champignons fossiles. 110ème Congrès National de la Société Savante, Montpellier, 5:27–34.Google Scholar
Miller, M. A. 1976. Maysvillian (Upper Ordovician) chitinozoans from the Cincinnati region of Ohio, Indiana, and Kentucky. Unpublished , Ohio State University, 251 p.Google Scholar
Mimller, M. A. 1996. Chitinozoa, p. 307–336. In Jansonius, J. and McGregor, D. C. (eds.), Palynology: Principles and Applications. American Association of Stratigraphic Palynologists Foundation, Dallas, 1.Google Scholar
Montenari, M., and Maass, R. 1996. Die metamorphen schiefer der Badenweiler-Lenzkirch-Zone/Südschwarzwald—Paläontologische altersstellung (Acritarchen und Chitinozoen) und tectonik. Berichte der Naturforschenden Gesellschaft zu Freiburg i. Br., 84/85:33–79.Google Scholar
Nestor, V. 1994. Early Silurian chitinozoans of Estonia and north of Latvia. Academia, 4, 63 p.Google Scholar
Nõlvak, J. 1980. Chitinozoans in biostratigraphy of the northern East Baltic Ashgillian. A preliminary report. Acta Palaeontolgica Polonica, 25:253–260.Google Scholar
Nõlvak, J. and Grahn, Y. 1993. Ordovician chitinozoan zones from Baltoscandia. Review of Palaeobotany and Palynology, 79:245–269.CrossRefGoogle Scholar
Oulebsir, L., and Paris, F. 1993. Nouvelles espèces de chitinozoaires dans l'Ordovicien inférieur et moyen du sud-est du Sahara algérien. Revue de Micropaléontologie, 36:269–292.Google Scholar
Paris, F. 1976. Les Chitinozoaires, p. 93–133. In Lardeux, H. (ed.), Mémoire de la Société géologique et minéralogique de Bretagne, Rennes, 19.Google Scholar
Paris, F. 1981. Les Chitinozoaires dans le Paléozoïque du sud-ouest de l'Europe (cadregéologique—étude systématique—biostratigraphie). Mémoire de la Société géologique et minéralogique de Bretagne, Rennes, 26, 496 p.Google Scholar
Paris, F. 1989. Chitinozoans, p. 280–284. In Holland, C. H. and Bassett, M. G. (eds.), A Global Standard for the Silurian System. National Museum of Wales, Geological Series, Memoir number 9, Cardiff.Google Scholar
Paris, F. 1996. Chitinozoan biostratigraphy and palaeoecology, p. 531–552. In Jansonius, J. and McGregor, D. C. (eds.), Palynology: principles and applications. American Association of Stratigraphic Palynologists Foundation, Dallas, 2.Google Scholar
Paris, F. and Bernard, D. 1994. “PHOTOCHITINO,” an image-incorporated electronic database for chitinozoan identification. Abstracts, Symposium on Palynology, Palaeoenvironments and Stratigraphy, Commission Internationale de Microflore du Paléozoïque, Sheffield, 1:32.Google Scholar
Paris, F. and Grahn, Y. 1996. Chitinozoa of the Silurian-Devonian boundary sections in Podolia, Ukraine. Palaeontology, 39:629–641.Google Scholar
Paris, F. and Nõlvak, J. In press. Evolution of the paleobiodiversity of a cryptic fossil group: the example of the “chitinozoan-animals”. Geobios.Google Scholar
Paris, F., Laufeld, S., and Chlupac, I. 1981. Chitinozoa of the Silurian-Devonian boundary stratotypes in Bohemia. Sveriges Geologiska Undersökning, Serie Ca 51, 29 p.Google Scholar
Poumot, C. 1968. Amphorachitina, Ollachitina, Velatachitina, trois nouveaux genres de Chitinozoaires de l'Erg oriental (Algérie-Tunisie). Bulletin du Centre de Recherche de Pau, 2:45–55.Google Scholar
Priewalder, H. 1997. SEM-revision of a chitinozoan assemblage from the uppermost San Pedro Formation (Pridoli), Cantabrian Mountains (Spain). Jahrbuch der Geologischen Bundesandstalt, 140:73–93.Google Scholar
Reid, P. C., and John, A. W. G. 1981. A possible relationship between Chitinozoa and Tintinnids. Review of Palaeobotany and Palynology, 34:251–262.CrossRefGoogle Scholar
Schallreuter, R. 1963. Neue Chitinozoen aus ordovizischen Geschieben und Bemerkungen zur Gattung Illichitina. Palaeontologische Abhandlungen, 1:392–405.Google Scholar
Schallreuter, R. 1981. Chitinozoen aus dem Sularpschieffer (Mittelordoviz) von Schonen (Schweden). Palaeontographica B, 178:89–142.Google Scholar
Schallreuter, R. 1983. Sularpschiefer (Mittelordoviz) als Geschiebe in Norddeutschland. Mitteilungen aus Dem Geologisch-Paläontologischen Institut Universität Hambourg, 54:55–64.Google Scholar
Schweineberg, J. 1987. Silurische Chitinozoen aus der Provinz Palencia (Kantabrisches Gebirge, N-Spanien). Göttinger Arbeiten zur Geologie und Paläontologie, 33:1–122.Google Scholar
Sommer, F. W., and Boekel, N. M. Van. 1964. Quitinozoários do Devoniano de Goias. Anais Da Academia Brasileira De Ciěncias, 36:423–431.Google Scholar
Staplin, F. L. 1961. Reef-controlled distribution of Devonian microplankton in Alberta. Palaeontology, 4:392–424.Google Scholar
Sutherland, S. J. E. 1994. Ludlow chitinozoans from the type area and adjacent regions. Palaeontological Society Monographs, London, 148, 104 p.Google Scholar
Swire, P. H. 1990. New Chitinozoan taxa from the Lower Wenlock (Silurian) of the Welsh Borderlands, England. Journal of Micropalaeontology, 9:107–113.CrossRefGoogle Scholar
Tappan, H. 1966. Chitinozoan classification. Journal of Paleontology, 40:1394–1396.Google Scholar
Tasch, P., and Hutter, T. J. 1978. Pennsylvanian Chitinozoans from eastern Kansas. Palinologia, 1:443–452.Google Scholar
Taugourdeau, P. 1961. Chitinozoaires du Silurien d'Aquitaine. Revue de Micropaléontologie, 4:135–154.Google Scholar
Taugourdeau, P. 1962. Associations de Chitinozoaires dans quelques sondages de la region d'Edjelé (Sahara). Revue de Micropaléontologie, 4:229–236.Google Scholar
Taugourdeau, P. 1965. Les Chitinozoaires. Unpublished doctoral dissertation, University of Paris, 101 p.Google Scholar
Taugourdeau, P. 1966. Les Chitinozoaires, techniques d'études, morphologie et classification. Mémoire de la Société Géologique de France, Nouvelle Série, 45, 64 p.Google Scholar
Taugourdeau, P. 1967. Néotypes de Chitinozoaires. Revue de Micropaléontologie, 9:258–264.Google Scholar
Taugourdeau, P. 1981. Les diverses attributions systématiques proposées pour les Chitinozoaires. Cahiers de Micropaléontologie, 1:17–28.Google Scholar
Taugourdeau, P. and De Jekhowsky, B. 1960. Répartition et description des Chitinozoaires siluro-dévoniens de quelques sondages de la C.R.E.P.S., de la C.F.P.A. et de la S.N. Repal au Sahara. Revue de l'Institut Français du Pétrole, 15:1199–1260.Google Scholar
Taugourdeau, P., Bouché, P., Combaz, A., Magloire, L., and Millepied, P. 1967. Microfossiles organiques du Paléozoïque. Les Chitinozoaires (1): Analyse bibliographique illustrée. Éditions du Centre National de la Recherche Scientifique, Paris, 121 p.Google Scholar
Tekbali, A. O., and Wood, G. D. 1991. Silurian spores, acritarchs and chitinozoans from the Bani Walid Borehole of the Gadamis Basin, northwest Libya, p. 1243–1273. In Salem, M. J. (ed.), Geology of Libya, VI. Elsevier, Amsterdam.Google Scholar
Tsegelnyuk, P. D. 1982. Silurian Chitinozoan from Podolia. Naukova dumka, Kiev, 160 p. (In Russan)Google Scholar
Urban, J. B. 1972. A reexamination of Chitinozoa from the Cedar Valley Formation of Iowa with observations on their morphology and distribution. Bulletins of American Paleontology, 63(275):1–43.Google Scholar
VanOyen, F. H. Oyen, F. H., and Calandra, F. 1963. Note sur les Chitinozoaires. Revue de Micropaleontologie, 6:13–18.Google Scholar
Verniers, J., Nestor, V., Paris, F., Dufka, P., Sutherland, S., and Van Grootel, G. 1995. A global Chitinozoa biozonation for the Silurian. Geological Magazine, 132:651–666.CrossRefGoogle Scholar
Wilson, L. R., and Dolly, E. D. 1964. Chitinozoa in the Tulip Creek Formation, Simpson Group (Ordovician), of Oklahoma. Oklahoma Geological Notes, 24(10):224–232.Google Scholar
Wilson, L. R., and Hedlund, R. W. 1964. Calpichitina scabiosa, a new Chitinozoan from the Sylvan Shale (Ordovician) of Oklahoma. Oklahoma Geological Notes, 24(7):161–164.Google Scholar
Wood, G. D. 1994. Togachitina, a new bilayered chitinozoan genus from the Devonian of the Sierra Subandinas Region, Bolivia. Palynology, 18:195–204.CrossRefGoogle Scholar
Wood, G. D. and Miller, M. A. 1991. Distinctive Silurian chitinozoans from the Itacurubá Group (Vargas Pena Shale), Chaco Basin, Paraguay. Palynology, 15:181–192.CrossRefGoogle Scholar
Wrona, R. 1980. Upper Silurian-Lower Devonian Chitinozoa from the subsurface of southeastern Poland. Palaeontologia Polonica, 41:103–165.Google Scholar
Zaslavskaya, N. M. 1980. Silurian Chitinozoa from the Siberian Platform. Akademia Nauk SSR, 435:52–80. (In Russian)Google Scholar