Abstract
Several exceptionally well-preserved phragmocones of the belemnite Conobelus, with approximately 20 chambers preserved, were collected from the Valanginian of the Crimean Peninsula (Black Sea). The shell structure was studied with SEM. The prismatic wall of the protoconch wedges out near the mural part of the first septum, a short distance after the closing membrane. The prismatic protoconch wall consists of sublayers. In the extremely thin shell wall at the apex, there is a single sublayer. Additional sublayers appear on the inner shell surface at some distance from the apex. The closing membrane, about as thick as the shell wall, is not continuous with wall of the protoconch and conotheca. The primordial rostrum is structurally different from the rostrum, and separated from it by an organic membrane. The first 20 chambers, at least, seem to lack the conotheca proper. The shell wall is here composed of long mural parts of the septa and/or of the prismatic layer of the primordial rostrum. The first septum is prismatic; others are formed by the nacreous layer Type 2 (Mutvei, 1970), which in sections gives an impression of a granular structure; the mural parts of the septa show tabular nacre. At early ontogenetic stages, starting from the sixth septal neck, the transformation from retro- to prochoanitic septal necks occurs. The replacement of retrochoanitic septal necks by prochoanitic (or transitional) necks in Conobelus is similar to that in am- monoids and in some other branches of cephalopods, and, consequently, represents an example of homeomorphy in cephalopod evolution. In addition, the present paper includes an ultrastructural comparison of early shell ontogeny in belemnites and bactritoids.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Abel, O., 1916, Paläobiologie der Cephalopoden aus der Gruppe der Dibranchiaten, Fischer (Jena), pp. 1–281.
Appellöf, A., 1893, Die Schalen von Sepia, Spirula und Nautilus, Studien über den Bau und das Wachsthum, Kongl. Svenska Vet. Akad. Handl, 25: 1–106.
Bandel, K., 1982, Morphologie und Bildung der frühontogenetisehen Gehäuse bei conchiferen Mollusken, Facies 7: 1–198s.
Bandel, K., Engeser, T., and Reitner, J., 1984, Die Embryonalentwicklung von Hibolites (Belemnitida, Cephalopoda), N. Jb. Geol. Paläeont. Abh, 167:275–303.
Bandel, K., and Kulicki, C, 1988, Belemnotheutis polonica: a belemnite with of Nautilus siphuneular tube, Paleobiology 8: 408–425.
Barskov, J. S., 1973, Microstructure of the skeletal layers of Sepia and Spirula compared with the shell layers of other mollusks, Palaeontol. Zh., a translation from Palaeontol. Zh, 3: 285–284. [in Russian]
Chamberlain, J. A., and Moore, W. A., 1982, Rupture strength and flow rate of Nautilus siphuneular tube, Paleobiology 8: 408–425.
Christensen, E., 1925, Neue Beitrage zum Bau der Belemniten, N. Jb. Mineral. Geol Paläeont, 51: 118–158.
Combemorel, R., 1972, Position systématique de Castellanibelus nov. gen. et de trois especes de belemnites du Crétacé Inferieur francais, Geobios 5: 67–81.
Dauphin, J., 1985, Implications of a microstructural comparison in some fossil and Recent Coleoid Cephalopod shells, Palaeontographica A 191:69–83.
Doguzhaeva, L., 1973, The internal structure of the shell of the genus Megaphyllites. Bull. Mosk. Obschestva Ispytateley Prirody Geol, 48(6): 161. [in Russian]
Doguzhaeva, L., 1988, Siphuncular tube and septal necks in ammonoid evolution, in: Cephalopods-Present and Past (J. Wiedmann and J. Kullmann, eds). Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, pp. 291–302.
Doguzhaeva, L., 1996a, The ultrastructure of the juvenile shells of Hemibactrites sp. (Cephalopoda: Bactritoidea), Dokl. Akad. Nauk 349:275–279. [in Russian]
Doguzhaeva, L., 1996b. Microstructure of the juvenile shell in bactritoids, ammonoids, orthoceroids and belem-noids, and its phylogenetic implication, in: Paleontology at the boundary of two centuries (80th anniversary of the Paleontol. l Soc, (N. V. Kruchinina & T.L. Modzalevskaya, eds.). Abstracts of the XLII session. of the Paleontol. Soc. of the Russian Academy of Sciences (January 29–February 2 1996), St-Peterburg, pp. 25–27. [in Russian]
Doguzhaeva, L.,1996c, Shell ultrastructure of the Early Permian bactritella and ammonitella, and its phylogenetic implication, in: Jost Wiedmann Symposium Cretaceous stratigraphy, paleobiology and paleobiogeography. Tubingen/Germany 7–9 March 1996, Abstracts, pp. 19–25.
Doguzhaeva, L., 1996d, Two Early Cretaceous spirulid coleoids of the northwestern Caucasus, their shell ultrastructure and evolutionary implications, Palaeontology 39:681–707.
Doguzhaeva, L., and Mutvei, H., 1986, Retro-and prochoanitic septal necks in ammonoids and transition between them, Palaeontographica A 195: 1–18.
Doguzhaeva, L., and Mutvei, H., 1993, Shell ultrastructure, muscle-scars, and buccal apparatus in ammonoids; in: 3erne Symposium International sur les Céphalopodes actuels et fossiles, Lyon (F) 17-23 juillet 1990 (S.Elmi, Ch. Mangold, and Y. Aimeras, eds), Geobios M. S. 15: 111–119.
Doguzhaeva, L, and Mutvei, H., 1996, Attachment of the body to the shell in ammonoids, in: Ammonoid Paleobiology (N. H Landmann., K. TAnabe and A. Davis, eds.). Topics in Geology 13, Plenum Press, pp. 43–63.
D’Orbigny, A., 1842, Paléontologie française, Terrains cretacees. Céphalopodes, Paris.
Druschits, V.V., and Doguzhaeva, L. A., 1974, Some morphogenetic characteristics of phylloceratids and lytoceratids (Ammonoidea), Palaeont. Zh, 1: 42–53. [in Russian]
Druschits, V. V., and Doguzhaeva, L. A., 1981, Ammonites in Scanning Electron Microscope, Moscow State University Press, pp. 1–238. [in Russian]
Druschits, V. V., Doguzhaeva, L., and Mikhailova, I. A., 1977, The structure of the ammonitella and direct development of the ammonites, Paleontol. Zh, 2: 57–69. [in Russian]
Druschits, V. V., Bogoslovskaya, M. F., and Doguzhaeva, L. A., 1976, Evolution of the septal necks in ammonoids, Paleontol. Zh. 1: 41–56. [in Russian]
Erben, H. K., 1960, Primitive Ammonoidea aus dem Unterdevon Frankreichs und Deutschlands, N. Jb. Geol. und Palaeontol, Abh. 11:1–128.
Erben, H. K., 1964, Die Evolution der îltesten Ammonoidea, N. Jb. Geol. und Paleontol, Abh. 120:107–212.
Flower, R. H., 1954, Cambrian cephalopods, Bull. New Mexico Bur. Min. and Mineral. Res, 40: 1–54.
Flower, R. H., and Gordon, M., 1959, More Mississippian belemnites, J. Paleontol, 33:809–842.
Foerste, A. F., 1925, Cephalopods from Nestayemi and Sulmeneva Fiords in Novaya Zemlya, Norske Vidensk. Akad., pp. 1–38.
Granjean, F., 1910, Le siphon des ammonites et des belemnites, Bull. Soc. geol. France, Sen 4 10:495–519.
Jeletzky, J. A., 1966, Comparative morphology, phylogeny, and classification of fossil Coleoidea, Univ. of Kansas Paleont. Contributions, Mollusca 7, pp. 1–162.
Jeletzky, J. A., 1980, Dicoelitid belemnites from the Toarcian-Middle Bajocian of Western and Arctic Canada, Bull. Geol. Surv. Canada 338: 1–71.
Kabanov, G. K., 1963, The phragmocone of Pseudobelus bipartitus from the Valanginian of the Crimea, Palaeontol. Zh, 4: 121–123. [in Russian]
Kabanov, G.K., 1967, The skeleton of belemnitids; its morphology and biological analysis, Trudy Palaeont. Inst, 144:1–100. [in Russian]
Müller-Stoll, H., 1936, Beitrage zur Anatomie der Belemnoidea, Nova Acta Leopoldina New Ser. 4: 159–226.
Mutvei, H., 1964, On the shells of Nautilus and Spirula with notes on the shell secretion in non-cephalopod molluscs, Arkivför zool, 16: 221–278.
Mutvei, H., 1970, Ultrastructure ofthe mineral and organic components of molluscan nacreous layer, Biominerali-zation 2: 48–72.
Naef, A. 1922, Die Fossilien Tintenfische; eine paleozoologische Monographie, Berlin, pp. 1–322.
Stolley, E.,1919, Die Systematik der Belemniten, Jahresber. Niedersächsischen geol. Vereins zu Hannover 11: 1–59.
Voltz, M., 1830, Observations sur les belemnites, Mem. Soc. Mus. Hist. Nat. Strasbourg 1: 1–70.
Zhuravleva, F. A., 1994, Septal necks in cephalopod evolution, Palaeontol. Zh, 3: 55–69. [in Russian]
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1999 Springer Science+Business Media New York
About this chapter
Cite this chapter
Doguzhaeva, L.A., Mutvei, H., Kabanov, G.K., Donovan, D.T. (1999). Conch Ultrastructure and Septal Neck Ontogeny of the Belemnite Conobelus (Duvaliidae) from the Valanginian of the Crimea (Black Sea). In: Olóriz, F., RodrÃguez-Tovar, F.J. (eds) Advancing Research on Living and Fossil Cephalopods. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-4837-9_16
Download citation
DOI: https://doi.org/10.1007/978-1-4615-4837-9_16
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-7193-9
Online ISBN: 978-1-4615-4837-9
eBook Packages: Springer Book Archive