Cephalopoda

Cephalopoda Cuvier, 1797

Cephalopods

Taxon overview

Cephalopoda  or cephalopods are extraordinary molluscs equipped with vertebrate-like intelligence and a unique buoyancy system for locomotion. Cephalopods evolved during the Cambrian where external shell was modified into a chambered buoyancy apparatus. During the mid-Palaeozoic cephalopods diverged into nautiloids and the presently dominant coleoids. Coleoids (i.e. squids, cuttlefish and octopods) internalised their shells which appears to be a unique evolutionary event. The general tendency of shell reduction reflects a trend towards active modes of life and much more complex behaviour.

Cephalopods are exclusively marine animals. They are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishermen sometimes call them inkfish, referring to their common ability to squirt ink. About 800 living species of cephalopods have been identified. Two important extinct taxa are the Ammonoidea (ammonites) and Belemnoidea (belemnites).

Selection of related publications
Kröger, B. & Aubrechtová, M. 2018. Cephalopods from reef limestone of the Vasalemma Formation, northern Estonia (latest Sandbian, Upper Ordovician) and the establishment of a local warm-water fauna. Journal of Systematic Palaeontology 16, 10, 799-839. DOI:10.1080/14772019.2017.1347212
Vinn, O., Ernst, A., Toom, U. & Isakar, M. 2018. Cryptic encrusting fauna inside invertebrate fossils from the Ordovician of Estonia. Annales Societatis Geologorum Poloniae 88, 3, 285-290. DOI:10.14241/asgp.2018.008
Aubrechtová, M. & Meidla, T. 2016. The oldest ascocerid cephalopod from the Silurian of Estonia and notes on the biogeography of the order Ascocerida (class Cephalopoda). Estonian Journal of Earth Sciences 65, 2, 1-7. DOI:10.3176/earth.2016.07
Mutvei, H. 2015. Characterization of two superorders Nautilosiphonata and Calciosiphonata and a new order Cyrtocerinida of the subclass Nautiloidea; siphuncular structure in the Ordovician nautiloid Bathmoceras (Cephalopoda). GFF 137, 3, 164-174. DOI:10.1080/11035897.2015.1061592
Klug, C., De Baets, K., Kröger, B., Bell, M. A., Korn, D. & Payne, D. 2015. Normal giants? Temporal and latitudinal shifts of Palaeozoic marine invertebrate gigantism and global change . Lethaia 48, 2, 267-288. DOI:10.1111/let.12104
King, A. H. 2014. Taxonomic review of early Darriwilian estonioceratids (Tarphycerida, Nautiloidea) from Sweden, Estonia, and the ‘Diluvium-Geschiebe’ ofnorthern Germany and Poland. Denisia 32, 47-57.
Kröger, B. 2013. The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden. European Journal of Taxonomy 41, 1-110. DOI:10.5852/ejt.2013.41
Kröger, B. 2012. The "Vaginaten": the dominant cephalopods of the Baltoscandian Mid Ordovician endocerid limestone. GFF 134, 2, 115-132. DOI:10.1080/11035897.2012.691897
Mutvei, H. & Dunca, E. 2011. Siphuncular structure in the orders Tarphycerida and Barrandeocerida (Cephalopoda: Nautiloidea). Palaeontology 54, 3, 705-710. DOI:10.1111/j.1475-4983.2011.01041.x
Kröger, B., Ebbestad, J. O., Högström, A. E. S. & Frisk, A. M. 2011. Mass concentration of Hirnantian cephalopods from the Siljan District, Sweden; palaeoecology and palaeobiogeographic relationships. Fossil Record 14, 1, 35-53. DOI:10.1002/mmng.201000014
Kröger, B., Zhang, Y. & Isakar, M. 2009. Discosorids and Oncocerids (Cephalopoda) of the Middle Ordovician Kunda and Aseri Regional Stages of Baltoscandia and the early evolution of these groups. Geobios 42, 3, 273-292. DOI:10.1016/j.geobios.2008.09.006
Kröger, B. 2007. Concentrations of juvenile and small adult cephalopods in the Hirnantian cherts (Late Ordovician) of Porkuni, Estonia. Acta Palaeontologica Polonica 52, 3, 591-608.
Kröger, B. & Isakar, M. 2006. Revision of annulated orthoceridan cephalopods of the Baltoscandic Ordovician. Fossil Record 9, 1, 137-163. DOI:10.1002/mmng.200600005
Kröger, B. & Mutvei, H. 2005. Nautiloids with multiple paired muscle scars from Lower-Middle Ordovician of Baltoscandia. Palaeontology 48, 4, 781-791. DOI:10.1111/j.1475-4983.2005.00478.x
Kröger, B., Klug, C. & Mapes, R. 2005. Soft−tissue attachments in orthocerid and bactritid cephalopods from the Earlyand Middle Devonian of Germany and Morocco. Acta Palaeontologica Polonica 50, 2, 329–342.
Kröger, B. 2004. Revision of Middle Ordovician orthoceratacean nautiloids from Baltoscandia. Acta Palaeontologica Polonica 49, 1, 57-74.
Mutvei, H. 2002. Connecting ring structure and its significance for classification of the orthoceratid cephalopods. Acta Palaeontologica Polonica 47, 1, 157-168.
King, A. H. 1999. A Review of Volkhovian and Kundan (Arenig-Llanvirn) Nautiloids from Sweden. Advancing Research on Living and Fossil Cephalopods. Olóriz F. & Rodríguez-Tovar F. J. (Eds.) , pp. 137-159. DOI:10.1007/978-1-4615-4837-9_11
Jacobson, M. 1999. Five new cephalopod species from the Silurian of Gotland. Examensarbeite i geologi vid Lunds Universitet , 108, 1-18.
Mutvei, H. 1998. Siphuncular structure in a Silurian narthecoceratid nautiloid cephalopod from the Island of Gotland. GFF 120, 4, 375-378. DOI:10.1080/11035899801204375
Mutvei, H. 1997. Siphuncular structure in Ordovician endocerid cephalopods. Acta Palaeontologica Polonica 42, 3, 375-390.
Frye, M. W. 1987. Upper Ordovician (Harjuan) oncoceratid nautiloids from the Boda Limestone, Siljan District, Sweden. GFF 109, 1, 83-99. DOI:10.1080/11035898709454748
Stridsberg, S. 1985. Silurian oncocerid cephalopods from Gotland. Fossils and Strata 18, 1-65.
Dzik, J. 1984. Phylogeny of the Nautiloids. Palaeontologia Polonica 45, 1-323.
Stumbur, H. & Mutvei, H. 1983. A new Middle Ordovician torticonic nautiloid. GFF 105, 1, 43-47. DOI:DOI: 10.1080/11035898309455293
Frye, M. W. 1982. Upper Ordovician (Harjuan) nautiloid cephalopods from the Boda Limestone of Sweden. Journal of Paleontology 56, 5, 1274-1295.
Stumbur, H. 1975. Biomertical characteristics of the shell of a living Nautilus. Proceedings of the Academy of Sciences of the Estonian SSR. Chemistry and Geology 1, 24, 78-90.
Saladžius, V. 1971. Cephalopods of the Ludlowian and Downtonian deposits of the Upper Silurian of the Southern Baltic area. Palaeontology and stratigraphy of the Baltic and the Byelorussia, No III, pp. 205-208.
Mutvei, H. & Stumbur, H. 1971. Remarks on the Genus Pictetoceras (Cephalopoda: Ellesmerocerida). Bulletin of Geol. Institutions of the Univ. of Uppsala 2, 13, 117-122.
Balashov, Z. G. 1971. On the taxonomy and stratigraphic significance genus Eushantungoceras (supergenus Actinoceratoidea). Voprosy paleontologii , 61-65. Voprosy paleontologi, VI, pp. 61-65.
Rõõmusoks, A. 1970. Stratigraphy of the Viruan Series (Middle Ordovician) in Northern Estonia, I.
Balashov, Z. G. 1968. Ordovician Endoceratids from Soviet Union.
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Stumbur, H.A. 1962. Distribution of nautiloids in the Ordovician of Estonia with a description of some new genera. Trudy Instituta geologii AN ESSR 10, 131-148. ENSV Teaduste Akadeemia Geoloogia Instituudi Uurimused X, pp. 131-148.
Stumbur, H. A. 1960. On some ... of nautiloids. Paleontologicheski Zhurnal 4, 133-135.
Stumbur, H. A. 1960. On different ways of evolution of nautiloids. Proc. of the Academy of Sciences of the Estonian SSR. Ser. Tech. and Phys.-Mat. Sciences 9, 4, 368-378.
Stumbur, H. A. 1959. On the embryonic shells of some Ordovician Tarphyceratida. Paleontologicheski Zhurnal , 2, 25-29.
Mutvei, H. 1957. On the relations of the principal muscles to the shell in Nautilus and some fossil nautiloids. Arkiv för Mineralogi och Geologi 2, 10, 219-259. DOI:
Stumbur, H. A. 1956. On the nautiloids of Kohila Subseries (Upper Ordovician of East Baltic). Tartu Riikliku Ülikooli Toimetised 42, 176-185.
Balashov, Z. G. 1956. On the systematic position and stratigraphic meaning of the species Orthoceras. Yearbook of All-Union Paleontological Society XV, 223-247.
Balashov, Z. G. 1955. Genus Cochlioceratidae nom. nov.. Voprosy paleontologii , II, 55-60. Voprosy paleontologi, II, pp. 55-60.
Balashov, Z. G. 1955. Some new genera and species of Nautiloids from Ordovician of Baltics. Voprosy paleontologii , II, 45-54. Voprosy paleontologi, II, pp. 45-54.
Stumbur, H. 1955. Eesti NSV ülem-ordoviitsiumi nautiloididest. Diplomitöö; 16 fototahvlit, materjali nimekiri Stumburi tööde kaustas, pp. 1-159.
Stumbur, K. 1955. Siluri alumiste lademete ostrakoodidefaunast Eesti NSV-s. Diplomitöö nr. 47. Tartu, 67 lk., 10 fotot, juh. A. Rõõmusoks. Diplomotöö nr. 47, pp. 1-67.
Alichova, T. N., Balashova, E. A. & Balashov, Z. G. 1954. Field atlas of characteristic Ordovician and Silurian faunas of southern Lithuania.
Balashov, Z. G. 1953. Coiled and half-coiled nautiloids from the Ordovician of Baltics. Stratigraphy and fauna of the Ordovician and Silurian West Russian Platform, pp. 217-300.
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Teichert, C. 1930. Die Cephalopoden-Fauna der Lyckholm-Stufe des Ostbaltikums. Paläontologische Zeitschrift 12, 3/4, 264-312. DOI:10.1007/BF03044452
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