- Niko, S., 1989c:
- A new Devonian cephalopod from the Nakazato formation of the southern Kitakami mountains.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 156, pp. 291–295.
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- Niko, S., 1990a:
- Early Devonian (Gedinnian) actinocerid cephalopods from the Fukuji formation, central Japan.
- Journal of Paleontology, vol. 64, no. 4, pp. 595–600.
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- Niko, S., 1990b:
- Early Carboniferous (Viséan) cephalopods from the Hikoroichi formation, southern Kitakami mountains.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 159, pp. 554–561.
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- Niko, S. and Hamada, T., 1986:
- The Middle Silurian foraminifer (Saccamminopsis) from the Gion-yama formation, central Kyushu.
- Scientific Papers of the College of Arts and Sciences, the University of Tokyo, vol. 36, no. 2, pp. 173–178.
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- Niko, S. and Hamada, T., 1987:
- Adnatoceras from Middle Carboniferous of the Ichinotani formation, Fukuji district, central Japan.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 148, pp. 223–227.
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- Niko, S. and Hamada, T., 1988:
- Early Devonian receptaculitid (Ischadites) from the Fukuji formation, central Japan.
- Journal of the Geological Society of Japan, vol. 94, no. 5, pp. 337–342, pl. 1.
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- Niko, S., Hamada, T. and Yasui, T., 1989:
- Silurian Orthocerataceae (Mollusca: Cephalopoda) from the Yokokurayama formation, Kurosegawa terrane.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 154, pp. 59–67.
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- Niko, S. and Nishida, T., 1987:
- Early Permian cephalopods from the Mizuyagadani formation, Fukuji district, central Japan.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 146, pp. 35–41.
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- Ohtsuka, Y., 1986:
- Early internal shell microstructure of some Mesozoic Ammonoidea: implications for higher taxonomy.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 141, pp. 275–288, pls. 45–50.
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- Oji, T., 1985:
- Early Cretaceous Isocrinus from northeast Japan.
- Palaeontology, vol. 28, pt. 4, pp. 629–642, pls. 77–79.
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- Oji, T., 1989:
- Distribution of the stalked crinoids from Japanese and nearby waters. In: Ohba, H., Hayami, I. and Mochizuki, K. (eds.) Current aspects of biogeography in west Pacific and east Asian resions.
- The University Museum, the University of Tokyo, Nature and Culture, no. 1, pp. 27–43.
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- Oji, T., 1990a:
- Miocene Isocrinidae (stalked crinoids) from Japan and their biogeographic implication.
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 157, pp. 412–429.
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- Oji, T., 1990b:
- Crinoidea.
- In: Japan Fisheries Resource Conservation Association,
Echinoderms from continental shelf and slope around Japan. vol. 1, pp. 23–34, pls. 1–3.
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- Okada, Y., 1981:
- Development of cell arrangement in ostracod carapaces.
- Paleobiology, vol. 7, no. 2, pp. 276–280.
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- Okada, Y., 1982:
- Ultrastructure and pattern of the carapace of Bicornucythere bisanensis (Ostracoda, Crustacea). In: Hanai, T. (ed.) Studies on Japanese Ostracoda.
- The University Museum, The University of Tokyo, Bulletin, no. 20, pp. 229–255, pls. 16–30.
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- Okamoto, T., 1984:
- Theoretical morphology of Nipponites (a heteromorph ammonoid).
- Fossils, no. 36, pp. 37–51, pl. 1. (in English with Japanese abstract)
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- Okamoto, T., 1988a:
- Analysis of heteromorph ammonoids by differential geometry.
- Palaeontology, vol. 31, pt. 1, pp. 35–52, pl. 7.
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- Okamoto, T., 1988b:
- Changes in life orientation during the ontogeny of some heteromorph ammonoids.
- Palaeontology, vol. 31, pt. 2, pp. 281–294.
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- Okamoto, T., 1988c:
- Developmental regulation and morphological saltation in the heteromorph ammonite Nipponites.
- Paleobiology, vol. 14, no. 3, pp. 272–286.
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- Okamoto, T., 1989:
- Comparative morphology of Nipponites and Eubostrychoceras (Cretaceous nostoceratids).
- Transactions and Proceedings of the Palaeontological Society of Japan. New Series, no. 154, pp. 117–139.
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