Colour patterns in Palaeozoic orthoceratoid cephalopods - diversification of striping

 

Authors: Manda Š, Turek V

Published in: Bulletin of Geosciences, volume 100, issue 4; pages: 739 - 783; Received 2 October 2025; Accepted in revised form 19 December 2025; Online 31 December 2025

Keywords: Cephalopoda, Orthoceratida, shell colouration, palaeoecology, Silurian, new taxa,

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Abstract

The evolution of shell colouration in Palaeozoic cephalopods is still poorly understood. To date, thirty-six species of orthoceratoids have been described that display colour patterns on their shell. Thirteen species are newly added herein or re-described from the Ludlow of Bohemia and two from the Mississippian of Belgium. The colour pattern is best documented in pseudorthoceratids. Some gaps in the fossil record still exist and seemingly separate periods dominated by specific types of shell colour patterns. Ordovician pseudorthoceratids have uniform, regular and evenly spaced longitudinal stripes. A similar but less regular type of colouration also occurs in Silurian pseudorthoceratids - rhythmised, irregular, interrupted and anastomosing colour stripes. After a gap in the Early Devonian, younger pseudorthoceratids possess a chevron pattern. A difference in the colour pattern in hatchlings and later growth stages is documented in the Carboniferous Pseudocyrtoceras. The restriction of colouration to the dorsal side of the shell in Devonian and Carboniferous pseudorthoceratids, which was previously interpreted as reflecting horizontal biological orientation of the shell and countershading, is questioned. The adaptive control and protective function of the shell colour patterns are indicated by the diversification of colour patterns in the Silurian, the emergence of the chevron pattern in the Devonian and early Carboniferous, the relationship between colour patterns and shell shape, the colour pattern polymorphism, and the ontogenetic changes in colouration. The pseudorthoceratid Pellucidoceras gen. nov. is established herein. Its type species, the Silurian P. decipiens, shows an intraspecific variability in the number, width, and spacing of stripes, and possibly represents case of colour pattern polymorphism.

References

Aberhan, M.N., Nurnberg, S. & Kiessling, W. 2012. Vision and the diversification of Phanerozoic marine invertebrates. Paleobiology 38, 187-204. View article

Angelin, N.P. & Lindström, G. 1880. Fragmenta Silurica. 60 pp. Samson and Wallin, Stockholm.

Archiac, É.J.A. & Verneuil, E.P. 1842. On the fossils of the older deposits in the Rhenish Provinces; preceded by a general survey of the fauna of the Palaeozoic rocks, and followed by a tabular list of the organic remains of the Devonian system in Europe. Transactions of the Geological Society of London, 2nd series 6, 303-410. View article

Balashov, Z.G. 1964. On the structure and colour patterns of the shell wall in some Ordovician endoceratoids of Baltic. Voprosy paleontologii 4, 106-110. [in Russian]

Barrande, J. 1865-1877. Systeme silurien du Centre de la Bohéme, I. ere partie: Recherches Paléontologiques, vol. II, Classe de Mollusques, Ordre des Céphalopodes, 1865. ser. 6, pl. 1-107; 1866. ser. 7, pl. 108-244; 1867. ser. 1, 712 pp.; 1868. ser. 8, pl. 245-350; 1870. ser. 2, 266 pp., ser. 9, pl. 351-460; 1874. ser. 3, 804 pp.; 1877. ser. 4, 742 pp., ser. 5, 743 pp., supplement 1, 297 pp., supplement 2, pl. 461-544. Privately published, Prague & Paris.

Barskov I.S. 1960. Silurian and Devonian nautiloids from southern Fergany. Moskovskoe Obshchestvo Ispytatelei Prirody, Byulletin, Odtel Geolicheskii 35, 153-154. [in Russian]

Barskov, I.S., Boiko, M.S., Konovalova, V.A., Leonova, T.B. & Nikolaeva, S.V. 2008. Cephalopods in the marine ecosystems of the Paleozoic. Paleontological Journal 42, 1167-1284. View article

Billings, E. 1857. New species of fossils from Silurian rocks of Canada, 343-345. In Report of Progress for the Years 1853-1856. Geological Survey of Canada, Ottava.

Blake, J.F. 1882. A monograph of the British fossil Cephalopoda. Part I. Introduction and Silurian species. 248 pp. London. View article

Boll, E. 1857. Beitrag zur kenntnis der silurischen Cephalopoden. 40 pp. Self-published, Schwerin.

Brett, C.E., Boucot, A.J. & Jones, B. 1993. Absolute depths of Silurian benthic assemblages. Lethaia 26, 25-40. View article

Caro, T. & Koneru, M. 2021. Towards an ecology of protective coloration. Biological Review 96, 611-641. View article

Chlupáč, I. 1987. Ecostratigraphy of Silurian trilobite assemblages of the Barrandian area, Czechoslovakia. Newsletter of Stratigraphy 17, 169-186. View article

Choo, B., Zhu, M., Zhao, W. et al. 2014. The largest Silurian vertebrate and its palaeoecological implications. Scientific Report 4, 5242. View article

Clarke, J.M. 1897. The Lower Silurian Cephalopoda of Minnesota. Minnesota Geological and Natural History Survey 3, 761-812.

Clarke, J.M. & Ruedemann, R. 1903. Guelph fauna in the state of New York. Memoir New York State Museum 5, 1-195. View article

Cook, A.G. 1994. Pigmentation bands on an Early Devonian nautiloid. Memoirs of the Queensland Museum 37, 40.

Donoghue, P.C.J., Purnell, M.A. & Aldridge, R.J. 1998. Conodont anatomy, chordate phylogeny and vertebrate classification. Lethaia 31, 211-219. View article

Dunstan, A., Ward, P. & Marshall, N. 2011. Nautilus pompilius Life History and Demographics at the Osprey Reef Seamount, Coral Sea, Australia. PloS One 6, e16312. View article

Dzik, J. 1984. Phylogeny of the Nautiloidea. Paleontologia Polonica 45, 1-255.

Ferretti, A. & Kříž, J. 1995. Cephalopod limestone biofacies in the Silurian of the Prague Basin, Bohemia. Palaios 10, 240-253. View article

Flower, R.H. 1939. Study of Pseudorthoceratidae. Palaeontographica Americana 11, 1-214.

Flower, R.H. 1955. Cameral deposits in orthoconic nautiloids. Geological Magazine 92, 89-103. View article

Flower, R.H. & Caster, K.E. 1935. The stratigraphy and paleontology of northwestern Pennsylvania, 2, Paleontology, A, The cephalopod fauna of the Conewango Series of the Upper Devonian in New York and Pennsylvania. Bulletins of American Paleontology 22, 1-57.

Foerste, A.F. 1924. Upper Ordovician faunas of Ontario and Quebec. Geological Survey of Canada, Memoir 132, 1-255. View article

Foerste, A.F. 1929. Devonian cephalopods from the Moose River Basin. Ontario Department of Mines, Annual Report 37, 70-78.

Foerste, A.F. 1930. The colour patterns in fossil cephalopods and brachiopods, with notes on gastropods and pelecypods. Contributions from the Museum of Palaeontology, Michigan 3, 109-150.

Foerste, A.F. 1932. Black River and other cephalopods from Minnesota, Wisconsin, Michigan, and Ontario (Part 1). Journal of the Scientific Laboratories of Denison University 27, 47-136.

Foerste, A.F. 1933. Black River and other cephalopods from Minnesota, Wisconsin, Michigan, and Ontario (Part 2). Bulletin Denison University, Journal of Scientific Laboratories 28, 1-136.

Foord, A.H. 1888. Catalogue of the fossil Cephalopoda in the British Museum (Natural History). Part 1. 344 pp. London, British Museum.

Frey, R.C. 1989. Paleoecology of a well-preserved nautiloid assemblage from a Late Ordovician shale unit, southwestern Ohio. Journal of Paleontology 63, 604-620. View article

Frey, R.C. 1995. Middle and Upper Ordovician nautiloid cephalopods of the Cincinnatti Arch region of Kentucky, Indiana, and Ohio. United States Geological Survey Professional Paper 1066-P, 1-126. View article

Gordon, M., Jr. 1964. Carboniferous cephalopods of Arkansas. United States Geological Survey, Professional Paper 460, 1-322. View article

Gekker, R.F. 1983. Taphonomic and ecological features of the fauna and flora of the Main Devonian Field. Trudy Paleontologičeskogo Instituta 190, 1-144. [in Russian]

Hall, J. 1847. Natural history of New York, Paleontology, vol. 1, containing descriptions of the organic remains of the lower division of the New-York system (equivalent of the Lower Silurian rocks of Europe). 338 pp. New York Geological Survey, Van Benthuysen, New York.

Havlíček, V. & Štorch, P. 1990. Silurian brachiopods and benthic communities in the Prague Basin (Czechoslovakia). Rozpravy Ústředního ústavu geologického 48, 1-275.

Havlíček, V. & Štorch, P. 1999. Silurian and Lochkovian Communities of the Prague Basin (Barrandian area, Czechoslovakia), 200-228. In Boucot, A.J. & Lawson, J.D. (eds) Final report, project Ecostratigraphy. Paleocommunities: A case study from the Silurian and Lower Devonian. Cambridge University Press, Cambridge.

Hewitt, R.A. & Watkins, R. 1980. Cephalopod ecology across a late Silurian shelf tract. Neue Jahrbuch für Geologie und Paläontologie, Abhandlungen 160, 96-117. View article

Histon, K. 2012. The Silurian nautiloid-bearing strata of the Cellon Section (Carnic Alps, Austria): color variation related to events. Palaeogeography, Palaeoclimatology, Palaeoecology 367-368, 232-256. View article

Hyatt, A. 1883-1884. Genera of fossil cephalopods. Proceedings of the Boston Society of Natural History 22, 253-338.

King, A.H. & Evans, D.H. 2019. High-level classification of the nautiloid cephalopods: a proposal for the revision of the Treatise Part K. Swiss Journal of Palaeontology 138(1), 65-85. View article

Kiselev, G.N. 1969. Silurian Cephalopoda of the Bolshezemelskaya Tundra and the north of the Urals. Author’s Abstract of Thesis. 22 pp. Izdatel’stovo Leningradskogo Universiteta, Leningrad.

Kobluk, R.D. & Hall, R.L. 1976. Preserved colour patterns in Ormoceras westonense from the Middle Ordovician of Quebec. Canadian Journal of Earth Sciences 13, 1479-1481. View article

Kobluk, D.R. & Mapes, R.H. 1989. The fossil record, function and possible origins of shell color Patterns in Paleozoic Marine invertebrates. Palaios 4, 63-85. View article

Koninck, L.G. de 1880. Faune de calcaire carbonifere de la Belgique, 2e partie, Gyroceras Cyrtoceras, Gomphoceras, Orthoceras, Subclymenia et Goniatites. Annales du Musée Royal d’Histoire naturelle de Belgique 5, 1-133.

Kříž, J. 1961. Průzkum zaniklé paleontologické lokality Joachima Barranda, označované jím jako „Butovitz“. Časopis pro mineralogii a geologii 6, 173-178.

Kříž, J. 1992. Silurian Field Excursions: Prague Basin (Barrandian), Bohemia. National Museum of Wales, Geological Series 13, 1-110.

Kříž, J. 1998a. Silurian, 79-101. In Chlupáč, I. Havlíček, V., Kříž, J., Kukal, Z. & Štorch, P. Palaeozoic of the Barrandian (Cambrian to Devonian). Český geologický ústav, Praha.

Kříž, J. 1998b. Recurrent Silurian-lowest Devonian cephalopod limestones of Gondwanan Europe and Perunica, 183-198. In Landing, E. & Johnson, M.E. (eds) Silurian cycles: Linkages of dynamic stratigraphy with atmospheric, oceanic, and tectonic changes. New York State Museum Bulletin 491.

Kröger, B. 2005. Adaptive evolution in Paleozoic coiled cephalopods. Paleobiology 31, 253-268. View article

Kröger, B. 2011. Size matters - Analysis of shell repair scars in endoceratid cephalopods. Fossil Record 14, 109-118. View article

Kröger, B. 2013. The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden. European Journal of Taxonomy (41). View article

Kröger, B & Aubrechtová, M. 2019. The cephalopods of the Kullsberg Limestone Formation, Upper Ordovician, central Sweden and the effects of reef diversification on cephalopod diversity. Journal of Systematic Palaeontology 17, 961-995. View article

Kröger, B. & Ebbestad, J.O.R. 2014. Palaeoecology and palaeogeography of Late Ordovician (Katian-Hirnantian) cephalopods of the Boda Limestone, Siljan district, Sweden. Lethaia, 47, 15-30. View article

Kröger, B., Servais, T. & Zhang, Y. 2009. The origin and initial rise of pelagic cephalopods in the Ordovician. PLoS One 4(e7262), 1-24. View article

Kuhn, O. 1940. Paläozoologie in Tabellen. 50 pp. Fischer Verlag, Jena.

Laptikhovsky, V., Nikolaeva, S. & Rogov, M. 2018. Cephalopod embryonic shells as a tool to reconstruct reproductive strategies in extinct taxa. Biological Reviews 93, 270-283. View article

Lesnikowa, A.F. 1949. Ortryad nautiloidei. Atlas rukovodjashikh form iskopaemykh faun SSSR 2, 253-261.

M’Coy, F. 1844. A synopsis of the characters of the Carboniferous limestone fossils of Ireland. 274 pp. University Press by M.H. Gill, Dublin. View article

Manda, Š. & Budil, P. 2007. Stop E1-6: Ludlow and early Přídolí succession at Mušlovka Quarry near Řeporyje; early Ludfordian radiation and the effect of the Ludfordian extinction events in the shallow-water carbonate succession, 25-34. In Elicki, O. & Schneider, E. (eds) Fossile Ökosysteme. Wissenschaftliche Mitteilungen, Institut für Geologie, Technische Universität Bergakademie Freiberg 34.

Manda, Š. & Kříž, J. 2006. Environmental and biotic changes of the subtropical isolated carbonate platforms during Kozlowskii and Lau events (Prague Basin, Silurian, Ludlow). GFF 128, 161-168. View article

Manda, Š. & Kříž, J. 2007. New cephalopod limestone horizon in the Ludlow (Gorstian, early L. scanicus Zone) of the Prague Basin (Bohemia, Perunica). Bollettino della Societá Paleontologica Italiana 46, 33-45.

Manda, Š. & Turek, V. 2009. Minute Silurian oncoceratids with unusual colour pattern (Nautiloidea). Acta Palaeontologica Polonica 54, 503-512. View article

Manda, Š. & Turek, V. 2015. Colour patterns on Silurian orthoceratid and pseudorthoceratid conchs from Gotland - palaeoecological implications. Estonian Journal of Earth Sciences 64, 74-79. View article

Manda, Š. & Turek, V. 2025. Ontogeny, muscle scars, colour pattern and predation marks in a Silurian orthoceratid cephalopod. Acta Palaeontologica Polonica 70, 517-541. View article

Mapes R.H. & Larson N.L. 2015. Ammonoid color patterns. Topics in Geobiology 43, 25-44. View article

Mapes, R.H., Hembree, D.I., Rasor, B.A., Stigall, A., Goirand, C. & Deforges, B.R. 2010. Modern Nautilus (Cephalopoda) taphonomy in a subtidal to backshore environment, Lifou (Loyalty Islands). Palaios 25, 656-670. View article

Marek, J. 1971. The genus Cyrtocycloceras Foerste, 1936 (Nautiloidea) from the Silurian of Central Bohemia. Sborník geologických věd, Paleontologie 14, 107-131.

Miagkova, E.I. 1967. Silurian nautiloids of the Siberian platform. 47 pp. Nauka, Moscow. [in Russian]

Miller, A.K. & Furnish, W.M. 1940. Studies of Carboniferous ammonoids: parts 1-4. Journal of Paleontology 14, 356-377. View article

Miller, S.A. 1875. Class Cephalopoda (Cuvier) as represented in the Cincinnati Group. Cincinnati Quarterly Journal of Science 2, 121-134.

Mutvei, H. 1957. On the relations of the principal muscles to the shell in Nautilus and some fossil nautiloids. Arkiv for Mineralogi och Geologi 2, 219-254.

Niko, S. 1998. Kobayashiceras gifuense, a new actinocerid cephalopod from the Lower Devonian of Japan. Journal of Paleontology 72(1), 36-38. View article

Niko, S. 2008. Isorthoceras wahlenbergi, a new Late Ordovician cephalopod from the Boda Limestone of Dalarna, Sweden. Paleontological Research 12, 195-198. View article

Niko, S., Sone, M. & Leman, M.S. 2020. Ordovician Orthoceratida and Pseudorthoceratida (Cephalopoda: Nautiloidea) from the Lower Setul Limestone of the Langkawi Islands, Malaysia. Journal of Systematic Palaeontology 18, 381-414. View article

Peterman, D.J., Barton, C.C. & Yacobucci, M.M. 2019. The hydrostatics of Paleozoic ectocochleate cephalopods (Nautiloidea and Endoceratoidea) with implications for modes of life and early colonization of the pelagic zone. Palaeontologia Electronica 22.2.27A, 1-29. View article

Pohle, A., Fuchs, D., Korn, D. & Klug, C. 2020. Spatial distribution of oncocerid cephalopods on a Middle Devonian bedding plane suggests semelparous life cycle. Scientific Reports 10, 2847. View article

Pohle, A., Kröger, B., Warnock, R.C.M., King, A.H., Evans, D.H., Aubrechtová, M., Cichowolski, M., Fang, X. & Klug, C. 2022. Early cephalopod evolution clarified through Bayesian phylogenetic inference. BMC Biology 20, 88. View article

Pohle, A., Hoffmann, R., Nützel, A., Seuss, B., Aubrechtová, M., Kröger, B., Stevens, K. & Immenhauser, A. 2025. Microstructural and geochemical evidence offers a solution to the cephalopod cameral deposits riddle. Palaeontology 68, e70032. View article

Ponder, W.F., Lindberg, D.R. & Ponder, J.M. 2019. Biology and Evolution of the Mollusca. Volume 1. 924 pp. CRC Press, Boca Raton, Florida. View article

Ristedt, H. 1968. Zur Revision der Orthoceratidae. Abhandlungen der mathematisch-naturwissenschaftlichen Klasse 4, 1-77.

Ristedt H. 1971. Zum Bau der orthoceriden Cephalopoden [On the construction of the orthocerid cephalopods]. Palaeontographica Abteilung A 137, 155-195.

Ruedemann, R. 1921. On color stripes in Orthoceras. Bulletin New York State Museum 227, 63-130.

Saemann, L. 1853. Üeber die Nautiliden. Palaeontographica 3, 121-163.

Schindewolf, O.H. 1943. Über das Apikalende der Actinoceren. Jahrbuch des Reichsamtes für Bodenforschung 62, 207-247.

Slavík, L. & Carls, P. 2012. Post-Lau Event (late Ludfordian, Silurian) recovery of conodont faunas of Bohemia. Bulletin of Geosciences 87, 815-832. View article

Sowerby, J.C. 1818. The Mineral Conchology of Great Britain, Volume 2. 251 pp. London.

Steele, H.M. & Sinclair, G.W. 1971. A Middle Ordovician fauna from Braeside, Ottawa Valley, Ontario. Geological Survey of Canada, Bulletin 211, 1-97. View article

Stevens, M. & Merilaita, S. 2009. Defining disruptive coloration and distinguishing its functions. Philosophical Transactions of the Royal Society B: Biological Sciences 364(1516), 481-488. View article

Stokes, C. 1840. On some species of Orthocerata. Transactions of the Geological Society of London 5, 705-714. View article

Štorch, P. 2023. Graptolite biostratigraphy and biodiversity dynamics in the Silurian System of the Prague Synform (Barrandian area, Czech Republic). Bulletin of Geosciences 98, 1-78. View article

Strand T. 1934. The Upper Ordovician Cephalopods of the Oslo Area. Norsk Geologiske Tidsskrift 14, 1-117.

Sweet, W.C. 1959. Muscle attachment impressions in some Paleozoic nautiloid cephalopods. Journal of Paleontology 33, 293-304.

Sweet, W.C. 1964. Nautiloidea-Orthocerida, K216-K261. In Moore, R.C. (ed.) Treatise on Invertebrate Paleontology, Part K, Mollusca 3, Cephalopoda. Geological Society of America and University of Kansas Press, Boulder.

Stridsberg, S. 1985. Silurian oncocerid cephalopods from Gotland. Fossils and Strata 18, 1-65. View article

Teichert, C. 1933. Der Bau der actinoceroiden Cephalopoden. Palaeontographica, Abteilung A 78, 111-230.

Teichert, C. 1964a. Morphology of hard parts, 13-53. In Moore, R.C. (ed.) Treatise on Invertebrate Paleontology, Part K, Mollusca 3, Cephalopoda. The Geological Society of America, Lawrence. View article

Teichert, C. 1964b. Actinoceratida, K190-K216. In Moore, R.C. (ed.) Treatise on invertebrate paleontology. Part K. Mollusca 3, Cephalopoda. General features, Endoceratoidea, Actinoceratoidea, Nautiloidea, Bactritoidea. Geological Society of America & University of Kansas Press, Boulder & Lawrence.

Teichert, C. 1967. Major features of cephalopod evolution. Special Publications of the University of Kansas 2, 162-210.

Teichert, C. & Glenister, B.F. 1953. Ordovician and Silurian cephalopods from Tasmania, Australia. Bulletins of American Paleontology 34, 5-66.

Tomašových, A., Schlogl, J., Biroň, A., Hudáčková, N. & Mikuš, T. 2017. Taphonomic clock and bathymetric dependence of cephalopod preservation in bathyal, sediment-starved environments. Palaios 32, 135-152. View article

Troedsson, G.T. 1926. On the middle and upper Ordovician faunas of Northern Greenland. 1. Cephalopods. Meddeleser on Gronland 71, 1-157.

Turek, V. 1974. Poznámky k sedimentaci „ortocerových vápenců“ Barrandienu. Časopis pro mineralogii a geologii 19, 165-169.

Turek, V. 1983. Hydrodynamic conditions and the benthic community of upper Wenlockian calcareous shales in the western part of the Barrandian (Kosov Quarry). Časopis pro mineralogii a geologii 28, 246-260.

Turek, V. 1987. On some epizoans of molluscs shells from the Upper Silurian (Přídolí) of the Barrandian area. Věstník Ústředního ústavu geologického 62, 105-111.

Turek, V. 1992. Ortocerové vápence a hlavonožci hraničních poloh kopaninského a přídolského souvrství v činném lomu na Kosově u Berouna. Časopis Národního muzea, Řada přírodovědná 158, 108.

Turek, V. 2009. Colour patterns in Early Devonian cephalopods from the Barrandian Area: Taphonomy and taxonomy. Acta Palaeontologica Polonica 54, 491-502. View article

Turek, V. & Manda, Š. 2010. Variability of colour pattern and shell malformations in Silurian nautiloid Peismoceras Hyatt, 1884. Journal of the National Museum, Natural History 179, 171-178.

Turek, V. & Manda, Š. 2012. “An endocochleate experiment” in the Silurian straight-shelled cephalopod Sphooceras. Bulletin of Geosciences 87, 767-813. View article

Turek, V. & Manda, Š. 2020. Discontinuous, asymmetric and irregular colour patterns in Silurian oncoceratids (Nautiloidea) with cyrtoconic shells. Bulletin of Geosciences 95, 333-367. View article

Turek, V., Marek, J. & Beneš, J. 1988. Fossils of the World. 495 pp. Paul Hamlyn Publishing, London.

Vokáč, V. 1999. Trilobitová společenstva hraničního intervalu ludlow-přídolí (silur) v novém profilu v lomu Kosov u Berouna (pražská pánev, Čechy). Palaeontologia Bohemiae 5(9), 70-74.

Ward, P., Dooley, F. & Barord, G.J. 2016. Nautilus: Biology, systematics, and paleobiology as viewed from 2015. Swiss Journal of Palaeontology 135, 169-185. View article

Watkins, R. 1993. The Silurian (Wenlockian) reef fauna of southeastern Wisconsin. Palaios 8, 325-338. View article

Webster R.J., Godin, J.-G.J. & Sherratt, T.N. 2015. The role of body shape and edge characteristics on the concealment afforded by potentially disruptive marking. Animal Behaviour 104, 197-202. View article

Weller, S. 1903. Report on paleontology, Geological Survey of New Jersey, vol. III, The Paleozoic Faunas. 462 pp. Trenton, J.L. Murphy publishing co.

Williams, T.S. 2017. Molluscan shell colour. Biological reviews 92, 1039-1058. View article

Zhuravleva, F.A. 1959. O semeistve Pseudorthoceratidae Flower & Caster, 1935. Akademia nauk SSSR, Doklady 116, 677-680. [in Russian]

Zhuravleva, F.A. 1964. New Ordovician and Silurian Cephalopoda of the Siberian Platform. Paleontologicheskii Zhurnal 1964(4), 87-100. [in Russian]

Zhuravleva, F.A. 1961. Nekotoriye Paleozoiiskie nautiloidei Podolii. Paleontologicheskii Zhurnal 1961(4), 55-59. [in Russian] View article

Zhuravleva F.A. 1978. Devonskie Ortocerodyi-Nadotryad Orthoceratoidea. Trudy Paleontologicheskogo Instituta 168, 1-222.