Morphology of the Jaws and Radula in Ammonoids

  • Marion Nixon
Part of the Topics in Geobiology book series (TGBI, volume 13)


Some ammonoids have been found with structures still in the living chamber that are now recognized as jaws (beaks or mandibles) because small teeth, characteristic of those of the radula of extant Cephalopoda, lie between upper and lower jaws. The radulae so far found in ammonoids have the same number of teeth in each transverse row as do those of living Coleoidea, and the teeth are of similar shape and form. The first discovery was of just a few teeth in Eoasianites (Closs and Gordon, 1966), a member of the taxon Goniatitina. A year later, eight specimens of the same species, in which the radula and jaws were preserved together, were reported (Gloss, 1967). The jaws and radulae of two adult microconchs of Eleganticeras elegantulum, a Liassic ammonite, were found by Lehmann (1967); other descriptions have followed, mostly of jaws but also of radulae (for reviews see Lehmann, 1971a, 1981a,b, 1988, 1990; Dagys et al.,1989).


Lateral Tooth Body Chamber Shell Diameter Marginal Tooth Outer Plate 


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  1. Altman, J. S., and Nixon, M., 1970, Use of the beaks and radula by Octopus vulgaris, J. Zool. (Lond.) 161: 25–38.CrossRefGoogle Scholar
  2. Arkell, W. J., 1957, Aptychi, in: Treatise on Invertebrate Paleontology, Part L, Mollusca 4 ( R. C. Moore, ed.), Geological Society of America and University of Kansas Press, Lawrence, KS, pp. 437–440.Google Scholar
  3. Arkell, W. J., Kummel, B., and Wright, C. W., 1957, Systematic descriptions, in: Treatise on Invertebrate Paleontology, Part L, Mollusca 4 ( R. C. Moore, ed.), Geological Society of America, and University of Kansas Press, Lawrence, KS, pp. 129–464.Google Scholar
  4. Bandel, K., 1988, Operculum and buccal mass of ammonites, in: Cephalopods—Present and Past ( J. Wiedmann and J. Kullman, eds.), Schweitzerbart’sche Verlagsbuchhandlung, Stuttgart, pp. 653–678.Google Scholar
  5. Clarke, M. R., 1962, The identification of cephalopod “beaks” and the relationship between beak size and total body weight, Bull. Br. Mus. (Nat. Hist.) Zool. 8 (10): 421–480.Google Scholar
  6. Clarke, M. R., 1980, Cephalopoda in the diet of sperm whales of the Southern Hemisphere and their bearing on sperm whale biology, Discov. Rep. 37: 1–324.Google Scholar
  7. Clarke, M. R., ed., 1986, A Handbook for the Identification of Cephalopod Beaks, Clarendon Press, Oxford.Google Scholar
  8. Closs, D., 1967, Goniatiten mit Radula und Kieferapparat in der Itararé Formation von Uruguay, Paldont. Z. 41: 19–37.Google Scholar
  9. Class, D.. and Gordon, M.. Jr., 1966, An Upper Paleozoic radula, Notas Estud. 1: 73–75.Google Scholar
  10. Crick, R. E., Burkart, B., Chamberlain, J. A., Jr., and Mann, K. O., 1985. Chemistry of calcified portions of Nautilus pompilius, J. Mar. Biol. Assoc. U.K. 65: 415–420.CrossRefGoogle Scholar
  11. Dagys, A. S., Lehmann, U., Bandel, K., Tanabe, K., and Weitschat, W., 1989, The jaw apparati of ectocochleate cephalopods, Paldont. Z. 63: 41–53.Google Scholar
  12. Dilly, P. N., and Nixon, M., 1976, The cells that secrete the beaks in octopods and squids (Mollusca, Cephalopoda), Cell Tissue Res. 167: 229–241.PubMedCrossRefGoogle Scholar
  13. Doguzhaeva, L., and Mutvei, H., 1990, Radulae, aptychi and counteraptychi in Cretaceous ammonites (Mollusca: Cephalopoda), Dokl. Akad. Nauk SSSR 313: 192–195 (in Russian).Google Scholar
  14. Doguzhaeva, L., and Mutvei, H.. 1992, Radula of the Early Cretaceous ammonite Aconeceras (Mollusca: Cephalopoda), Palaeontogr. Abt. A 223: 167–177.Google Scholar
  15. Doguzhaeva, L. A., and Mutvei, H., 1993, Shell ultrastructure, muscle-scars, and buccal apparatus in ammonoids, Geobios Mém. Spéc. 15: 111–119.CrossRefGoogle Scholar
  16. Donovan, D. T., Calloman, J. H., and Howarth, M. K., 1981, Classification of the Jurassic Ammonitina, in: The Ammonoidea, Systematics Association Special Volume 18 ( M. R. House and J. R. Senior, eds.), Academic Press, London, pp. 101–155.Google Scholar
  17. Guerra, A., 1985, Food of the cuttlefish Sepia officinalis and S. elegans in the Ria de Vigo (NW Spain) (Mollusca: Cephalopoda), J. Zool. (Lund.) 207: 511–519.CrossRefGoogle Scholar
  18. Guerra, A., Nixon, M., and Castro, B. G., 1988, Initial stages of food ingestion by Sepia officinalis (Mollusca: Cephalopoda), J. Zool. (Land.) 214: 189–197.CrossRefGoogle Scholar
  19. Hunt, S., and Nixon, M., 1981, A comparative study of protein composition in the chitin–protein complexes of the beak, pen, sucker disc, radula and oesophageal cuticle of cephalopods, Comp. Biochem. Physiol. 68B: 535–546.Google Scholar
  20. Jacobs, D. K., and Landman, N. H., 1993, Nautilus—a poor model for the function and behavior of ammonoids? Lethaia 26: 101–111.Google Scholar
  21. Johnson, R. G., and Richardson, E. S., Jr., 1968, Ten-armed fossil cephalopod from the Pennsylvanian in Illinois, Science 159: 526–528.PubMedCrossRefGoogle Scholar
  22. Kaiser, P., and Lehmann, U., 1971, Vergleichende Studien zur Evolution des Kiefferapparates rezenter und fossiler Cephalopoden. Paläont. Z. 45: 18–32.Google Scholar
  23. Kanie, Y., 1982, Cretaceous tetragonatid ammonite jaws: A comparison with modern Nautilus jaws. Trans. Proc. Palaeont. Soc. Jpn. N.S. 125: 239–258.Google Scholar
  24. Kulicki, C., and Wierzbowski, A., 1983, The Jurassic ammonites of the Jagua Formation, Cuba, Acta Palaeontol. Pol. 28: 369–384.Google Scholar
  25. Kulicki, C., Doguzhaeva, L. A., and Kabanov, G. K., 1988, Nautilus-like jaw elements of a juvenile ammonite, in: Cephalopods—Present and Past (J. Wiedmann and J. Kullmann, eds.), Schweitzerbart’sche Verlagsbuchhandlung, Stuttgart, pp. 679–686.Google Scholar
  26. Kullmann, J., 1981, Carboniferous goniatites, in: The Ammonoidea, Systematics Association Special Volume 18 ( M. R. House and J. R. Senior, eds.), Academic Press, London, pp. 37–48.Google Scholar
  27. Landman, N. H., and Waage, K. M., 1993, Scaphitid ammonites of the Upper Cretaceous (Maastrichtian) Fox Hills Formation in South Dakota and Wyoming, Bull. Am. Mus. Nat. Hist. 215: 1–257.Google Scholar
  28. Lehmann, U., 1967, Ammoniten mit Kieferapparat und Radula aus Lias-Geschieben, Paläont. Z. 41: 38–45.Google Scholar
  29. Lehmann, U., 1970, Lias-Anaptychen als Kieferelemente (Ammonoidea), Paläont. Z. 44: 25–31.Google Scholar
  30. Lehmann, U., 1971a, New aspects in ammonite biology, in: Proceedings North American Paleontological Convention, September 1969, Part I, 1251–1269.Google Scholar
  31. Lehmann, U., 1971b, Jaws, radula, and crop of Arnioceras (Ammonoidea), Palaeontology (Lond.) 14: 338–341.Google Scholar
  32. Lehmann, U., 1972, Aptychen als Kieferelemente der Ammoniten, Paldont. Z. 46: 34–48.Google Scholar
  33. Lehmann, U., 1978, Über den Kieferapparat von Ammoniten der Gattung Parkinsonia, Mitt. Geol.-Paläont. Inst. Univ. Hamburg 48: 79–84.Google Scholar
  34. Lehmann, U., 1979, The jaws and radula of the Jurassic ammonite Dactylioceras, Palaeontology (Lond.) 22: 265–271.Google Scholar
  35. Lehmann, U., 1981a, The Ammonites: Their Life and Their World, Cambridge University Press, Cambridge.Google Scholar
  36. Lehmann, U., 1981b, Ammonite jaw apparatus and soft parts, in: The Ammonoidea, Systematics Association Special Volume 18 ( M. R. House and J. R. Senior, eds.), Academic Press, London, pp. 275–287.Google Scholar
  37. Lehmann, U., 1985, Zur Anatomie der Ammoniten: Tintenbeutel, Kiemen, Augen, Paläont. Z. 59: 99–108.Google Scholar
  38. Lehmann, U., 1988, On the dietary habits and locomotion of fossil cephalopods, in: Cephalopods—Present and Past ( J. Kullmann and J. Wiedmann, eds.), Schweitzerbart’sche Verlagsbuchhandlung, Stuttgart, pp. 633–640.Google Scholar
  39. Lehmann, U., 1990, Ammonoideen: Leben zwischen Skylla und Charybdis, Enke, Stuttgart.Google Scholar
  40. Lehmann. U., and Kulicki, C., 1990, Double function of aptychi (Ammonoidea) as jaw elements and opercula. Lethaia 23: 325–331.CrossRefGoogle Scholar
  41. Lehmann. U., and Weitschat, W., 1973, Zur Anatomie und Okologie von Ammoniten: Funde von Kropf und Kiemen, Paläont. Z. 47: 69–76.Google Scholar
  42. Lehmann, U., Tanabe, K., Kanie, Y., and Fukuda, Y., 1980, Über den Kieferapparat der Lytoceratacea (Ammonoidea), Paläont. Z. 54: 319–329.Google Scholar
  43. Lowenstam, H. A., Traub, W., and Weiner, S.. 1984, Nautilus hard parts: A study of the mineral and organic constituents, Paleobiology 10: 268–279.Google Scholar
  44. Meek, A. K., and Hayden, F. V., 1864, Palaeontology of the upper Missouri; Invertebrates, Smithson. Contrib. Know. 14: 118–121.Google Scholar
  45. Michael, R., 1894. Über Ammoniten-Brut mit Aptychen in der Wohnkammer von Oppelia steraspis, Z. Dtsch. Geol. Ges. 46: 697–702.Google Scholar
  46. Miller, A. K., Furnish, W. M., and Schindewolf, O. H., 1957, Paleozoic Ammonoidea, in: Treatise on Invertebrate Paleontology. Part L, Mollusca 4 ( R. C. Moore, ed.), Geological Society of America and University of Kansas Press, Lawrence. KS, pp. 11–79.Google Scholar
  47. Moore, R. C., and Sylvester-Bradley, P. C., 1957, Taxonomy and nomenclature of aptychi, in: Treatise on Invertebrate Paleontology, Part L, Mollusca 4 ( R. C. Moore, ed.), Geological Society of America and University of Kansas Press, Lawrence, KS, pp. 465–471.Google Scholar
  48. Morton, N., 1981, Aptychi: The myth of the ammonite operculum, Lethaia 14: 57–61.CrossRefGoogle Scholar
  49. Morton, N., and Nixon, M., 1987, Size and function of ammonite aptychi in comparison with buccal masses of modern cephalopods, Lethaia 20: 231–238.CrossRefGoogle Scholar
  50. Nesis, K. N., 1986, On the feeding and the causes of extinction of certain heteromorph ammonites, Paleont. Zh. 1: 8–15 (in Russian).Google Scholar
  51. Nixon, M., 1969, Growth of the beak and radula of Octopus vulgaris, J. Zool. (Lond.) 159: 363–379.Google Scholar
  52. Nixon, M., 1979, Hole-boring in shells by Octopus vulgaris in the Mediterranean, Malacologia 18: 431–443.Google Scholar
  53. Nixon, M., 1985, Capture of prey, diet, and feeding of Sepia officinalis and Octopus vulgaris (Mollusca: Cephalopoda) from hatchling to adult, Vie Milieu 35: 255–261.Google Scholar
  54. Nixon, M., 1987, Cephalopod diets, in: Cephalopod Life Cycles, Vol. II ( P. R. Boyle, ed.), Academic Press, London, pp. 201–219.Google Scholar
  55. Nixon, M., 1988a, The buccal mass of fossil and recent Cephalopoda, in: The Mollusco, Paleontology and Neontology of Cephalopods, Vol. 12 ( M. R. Clarke, and E. R. Trueman, eds.), Academic Press, San Diego, pp. 103–122.Google Scholar
  56. Nixon, M., 1988b, The feeding mechanisms and diets of cephalopods—living and fossil, in: Cephalopods—Present and Past ( J. Kullmann and J. Wiedmann, eds.), Schweitzerbart’sche Verlagsbuchhandlung, Stuttgart, pp. 641–652.Google Scholar
  57. Nixon, M., 1995a, A nomenclature for the radula of the Cephalopoda (Mollusca)—living and fossil, J. Zool. (Lond.) 236: 73–81.CrossRefGoogle Scholar
  58. Nixon, M., 1995b, The radulae of Cephalopoda, Smithson. Contrib. Zool. (in press).Google Scholar
  59. Nixon, M., and Boyle, P. R., 1982, Hole-drilling in crustaceans by Eledone cirrhosa (Mollusca: Cephalopoda), J. Zool. (Lund.) 196: 439–444.CrossRefGoogle Scholar
  60. Nixon, M., and Maconnachie, E., 1988, Drilling by Octopus vulgaris in the Mediterranean, J. Zool. (Lond.) 216: 687–716.CrossRefGoogle Scholar
  61. Saunders, W. B., and Richardson, E. S., Jr.. 1979, Middle Pennsylvanian (Desmoinesian) Cephalopoda of the Mazon Creek Fauna. Northeastern Illinois, in: Mazon Creek Fossils ( M. H. Nitecki, ed.), Academic Press. New York. pp. 333–359.Google Scholar
  62. Saunders, W. B., Spinosa, C.. Teichert, C., and Banks. R. C., 1978. The jaw apparatus of Recent Nautilus and its palaeontological implications, Palaeontology 21: 129–141.Google Scholar
  63. Schindewolf, O. H.. 1958, Über Aptychen (Ammonoidea), Palaeontogr. Abt. A 111: 1–46.Google Scholar
  64. Seilacher, A., 1993, Ammonite aptychi: How to transform a jaw into an operculum, Am. J. Sci. 293A: 20–32.CrossRefGoogle Scholar
  65. Tanabe, K., 1983, The jaw apparatuses of Cretaceous desmoceratid ammonites, Palaeontology (Lond.) 26: 677–686.Google Scholar
  66. Tanabe, K., and Fukuda, Y., 1987a, Mouth part histology and morphology, in: Nautilus—The Biology and Paleobiology of a Living Fossil ( W. B. Saunders and N. H. Landman, eds.), Plenum Press, New York. pp. 313–322.Google Scholar
  67. Tanabe K., and Fukuda, Y.. 1987b, The jaw apparatus of the Cretaceous ammonite Reesidites, Lethaia 20: 41–48.CrossRefGoogle Scholar
  68. Tanabe, K., and Mapes, R., 1995, Jaws and radula of the Carboniferous ammonoid Ammonoidea, Cravenoceras, J. Paleont. 69: 703–707.Google Scholar
  69. Tanabe, K., Fukuda, Y., Kanie, Y., and Lehmann, U., 1980a, Rhynocolites and conchorhynchs as calcified jaw elements in some Late Cretaceous ammonites, Lethaia 13: 157–168.Google Scholar
  70. Tanabe, K., Hirano, H., and Kanie, Y., 1980b, The jaw apparatus of Scalarites mihoensis, a late Cretaceous ammonite, in: Professor Saburo Kanno Memorial Volume, Institute of Geosciences, University of Tsukuba, Tsukuba, pp. 159–165.Google Scholar
  71. Teichert, C., Moore, R. C., and Zeller, D. E. N., 1964, “Rhyncholites” in: Treatise on Invertebrate Paleontology, Part K. Mollusca 3 ( R. C. Moore, ed.), Geological Society of America and University of Kansas Press, Lawrence, KS, pp. 467–484.Google Scholar
  72. Thore, S., 1949, Investigations on the “Dana” Octopoda. Part I. Bolitaenidae, Amphitretidae, Vitreledonellidae, and Alloposidae, Dana Rep. 6 (33): 1–85.Google Scholar
  73. Trauth, F., 1938, Die Lamellaptychi des Oberjura und der Unterkriede, Palaeontogr. Abt. A 88: 115–229.Google Scholar
  74. Ward, P., and Wicksten, M. K., 1980, Food sources and feeding behavior of Nautilus macromphal us, Veliger 23: 119–124.Google Scholar
  75. Westermann G E G, 1990, New developments in ecology of Jurassic—Cretaceous ammonoids. in: Atti del Secondo Convegno Internazionale, Fossili, Evoluzione. Ambiente, Pergola 1987 ( G. Pallini, F. Cecca, S. Cresta, and M. Santantonio, eds.), Technostampa, Ostra Vetere, Italy, Pp. 459–478.Google Scholar
  76. Wright, C. W., 1981, Cretaceous Ammonoidea, in: The Ammonoidea, Systematics Association Special Volume 18 ( M. R. House and J. R. Senior, eds.), Academic Press, London, pp. 37–48.Google Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • Marion Nixon
    • 1
  1. 1.Research School of Geological and Geophysical SciencesBirkbeck College and University College LondonLondonEngland

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