Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T11:02:38.074Z Has data issue: false hasContentIssue false

Mammal-like occlusion in conodonts

Published online by Cambridge University Press:  20 May 2016

Philip C. J. Donoghue*
Affiliation:
Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom. E-mail: [email protected] and [email protected]
Mark A. Purnell
Affiliation:
Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom. E-mail: [email protected] and [email protected]
*
Previous address: School of Earth Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom

Abstract

Conodont element function and feeding mechanisms are of considerable paleobiological importance, yet many details remain poorly understood and speculative. Analysis based on morphology, physical juxtaposition, and patterns of surface damage and microwear on pairs of Pa elements from individuals of Idiognathodus indicates that these elements crushed food by rotational closure, which brought the oral surfaces into complex interpenetrative occlusion. Other molariform conodont elements also functioned in this manner. Occlusion of this complexity is unique among nonmammalian vertebrates, and is all the more surprising given that conodonts lacked jaws. In addition to enhanced understanding of food processing in conodonts, our analysis suggests that many details of conodont Pa element morphology, which underpin taxonomy and biostratigraphy, can now be interpreted in a paleobiological, functional context.

Type
Articles
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Aldridge, R. J., Smith, M. P., Norby, R. D., and Briggs, D. E. G. 1987. The architecture and function of Carboniferous polygnathacean conodont apparatuses. Pp. 6376. in Aldridge, R. J. ed. Palaeobiology of conodonts Ellis Horwood, Chichester, England.Google Scholar
Aldridge, R. J. and Purnell, M. A. 1996. The conodont controversies. Trends in Ecology and Evolution 11: 463468.Google Scholar
Babcock, L. E. 1993. Trilobite malformations and the fossil record of behavioral asymmetry. Journal of Paleontology 67: 217229.Google Scholar
Baesemann, J. F. 1973. Missourian (Upper Pennsylvanian) conodonts of northeastern Kansas. Journal of Paleontology 47: 689710.Google Scholar
Bengtson, S. 1976. The structure of some Middle Cambrian conodonts, and the early evolution of conodont structure and function. Lethaia 9: 185206.Google Scholar
Bengtson, S. 1983. The early history of the conodonta. Fossils and Strata 15: 519.Google Scholar
Carroll, R. L. and Lindsay, W. 1985. The cranial anatomy of the primitive reptile Procolophon. Canadian Journal of Earth Sciences 22: 15711587.Google Scholar
Clark, J. M., Jacobs, L. L., and Downs, W. R. 1989. Mammal-like dentition in a Mesozoic crocodylian. Science 244: 10641066.Google Scholar
Crompton, A. W. and Hiiemae, K. 1970. Molar occlusion and mandibular movements during occlusion in the American opossum, Didelphis marsupialis L. Zoological Journal of the Linnean Society. 49: 2147.Google Scholar
DeMar, R. and Bolt, J. R. 1981. Dentitional organization and function in a Triassic reptile. Journal of Paleontology 55: 967984.Google Scholar
Donoghue, P. C. J. 1998. Growth and patterning in the conodont skeleton. Philosophical Transactions of the Royal Society of London B 353: 633666.Google Scholar
Donoghue, P. C. J. and Purnell, M. A. In press. Growth, function, and the conodont fossil record Geology.Google Scholar
Du Bois, E. P. 1943. Evidence on the nature of conodonts. Journal of Paleontology 17: 155159.Google Scholar
Fox, R. C., Youzwyshyn, G. P., and Krause, D. W. 1992. Post-Jurassic mammal-like reptile from the Palaeocene. Nature 358: 233235.Google Scholar
Gordon, K. D. 1982. A study of microwear on chimpanzee molars: implications for dental microwear analysis. American Journal of Physical Anthropology 59: 195215.Google Scholar
Janis, C. M. 1990. The correlation between diet and dental wear in herbivorous mammals and its relationship to the determination of diets of extinct species. Pp. 241259. in Boucot, A. J. ed. Evolutionary paleobiology of behavior and coevolution Elsevier, Amsterdam.Google Scholar
Jeppsson, L. 1971. Element arrangement in conodont apparatuses of Hindeodella type and in similar forms. Lethaia 4: 101123.Google Scholar
Jeppsson, L. 1979. Conodont element function. Lethaia 12: 153171.CrossRefGoogle Scholar
Kemp, A. 1977. The pattern of tooth plate formation in the Australian lungfish, Neoceratodus forsteri Krefft. Zoological Journal of the Linnean Society 60: 223258.Google Scholar
Klapper, G. 1971. Sequence within the conodont genus Polygnathus in the New York lower Middle Devonian. Geologica et Palaeontologica 5: 5979.Google Scholar
Klapper, G. and Lane, H. R. 1985. Upper Devonian (Frasnian) conodonts of the Polygnathus biofacies, N.W.T., Canada. Journal of Paleontology 59: 904951.Google Scholar
Kuz'min, A. V. 1990. Asymmetrical pairs of platform elements of Polygnathus (conodonts). Paleontological Journal 1990: 6270.Google Scholar
Lane, H. R. 1968. Symmetry in conodont element-pairs. Journal of Paleontology 42: 12581263.Google Scholar
Lindström, M. 1964. Conodonts. Elsevier, Amsterdam.Google Scholar
Maas, M. C. 1991. Enamel structure and microwear: an experimental study of the response of enamel to shearing force. American Journal of Physical Anthropology 85: 3149.Google Scholar
Maas, M. C. 1994. A scanning electron-microscope study of in vitro abrasion of mammalian tooth enamel under compressive loads. Archives of Oral Biology 39: 111.Google Scholar
Müller, K. J. and Nogami, Y. 1971. U¨ber die Feinbau der Conodonten. Memoirs of the Faculty of Science, Kyoto University, Series of Geology and Mineralogy 38: 187.Google Scholar
Müller, K. J. 1972. Growth and function of conodonts. Pp. 2027. in. 24th International Geological Congress, Montreal.Google Scholar
Nicoll, R. S. 1985. Multielement composition of the conodont species Polygnathus xylus xylus Stauffer, 1940 and Ozarkodina brevis (Bischoff and Ziegler, 1957) from the Upper Devonian of the Canning Basin, Western Australia. Bureau of Mineral Resources Journal of Australian Geology and Geophysics 9: 133147.Google Scholar
Nicoll, R. S. 1987. Form and function of the Pa element in the conodont animal. Pp. 7790. in Aldridge, R. J. ed. Palaeobiology of conodonts. Ellis Horwood, Chichester, England.Google Scholar
Nicoll, R. S. 1995. Conodont element morphology, apparatus reconstructions and element function: a new interpretation of conodont biology with taxonomic implications. Courier Forschungsinstitut Senckenberg 182: 247262.Google Scholar
Norby, R. D. 1976. Conodont apparatuses from Chesterian (Mississippian) strata of Montana and Illinois Ph.D. dissertation. University of Illinois at Urbana-Champaign.Google Scholar
Pough, F. H., Heiser, J. B., and McFarland, W. N. 1996. Vertebrate life, 4th ed. Prentice Hall, Upper Saddle River, N.J.Google Scholar
Purnell, M. A. 1993. Feeding mechanisms in conodonts and the function of the earliest vertebrate hard tissues. Geology 21: 375377.Google Scholar
Purnell, M. A. 1994. Skeletal ontogeny and feeding mechanisms in conodonts. Lethaia 27: 129138.Google Scholar
Purnell, M. A. 1995. Microwear on conodont elements and macrophagy in the first vertebrates. Nature 374: 798800.Google Scholar
Purnell, M. A.In press. Conodonts: functional analysis of disarticulated skeletal structures lacking extant homologues. Pp. 129146. in Savazzi, E. ed. Functional morphology of the invertebrate skeleton. Wiley, Chichester, England.Google Scholar
Purnell, M. A. and Donoghue, P. C. J. 1997. Skeletal architecture and functional morphology of ozarkodinid conodonts. Philosophical Transactions of the Royal Society of London B 352: 15451564.Google Scholar
Purnell, M. A. and Donoghue, P. C. J. 1998. Architecture and functional morphology of the skeletal apparatus of ozarkodinid conodonts. Palaeontology 41: 57102.Google Scholar
Purnell, M. A. and von Bitter, P. H. 1992. Blade-shaped conodont elements functioned as cutting teeth. Nature 359: 629631.Google Scholar
Rensberger, J. M. 1978. Scanning electron microscopy of wear and occlusal events in some small herbivores. Pp. 523. in Butler, P. M., Joysey, K. A. eds. Development, function and evolution of teeth. Academic Press, New York.Google Scholar
Rensberger, J. M. 1995. Determination of stresses in mammalian dental enamel and their relevance to the interpretation of feeding behaviors in extinct taxa. Pp. 151172. in Thomason, J. ed. Functional morphology in vertebrate paleontology. Cambridge University Press, Cambridge.Google Scholar
Rhodes, F. H. T. 1952. A classification of Pennsylvanian conodont assemblages. Journal of Paleontology 26: 886901.Google Scholar
Robinson, P. L. 1956. An unusual sauropod dentition. Zoological Journal of the Linnean Society 43: 283293.Google Scholar
Sandberg, C. A. and Ziegler, W. 1979. Taxonomy and biofacies of important conodonts of Late Devonian styriacus Zone, United States and Germany. Geologica et Palaeontologica 13: 173212.Google Scholar
Sansom, I. J. 1996. Pseudooneotodus: a histological study of an Ordovician to Devonian vertebrate lineage. Zoological Journal of the Linnean Society 118: 4757.Google Scholar
Sansom, I. J., Smith, M. P., Armstrong, H. A., and Smith, M. M. 1992. Presence of the earliest vertebrate hard tissues in conodonts. Science 256: 13081311.Google Scholar
Smith, K. K. 1993. The form of the feeding apparatus in terrestrial vertebrates: studies of adaptation and constraint. Pp. 150196. in Hanken, J., Hall, B. F. eds. The skull. University of Chicago Press, Chicago.Google Scholar
Stamm, R. G. 1996. Reversals of misfortune: a new species? of Idiognathodus (Conodonta) based on functional surface morphology. In Repetski, J. E. ed. Sixth North American Paleontological Convention Abstracts of Papers Paleontological Society Special Publication. 8: 369. Smithsonian Institution Press, Washington, D.C.Google Scholar
Sweet, W. C. 1985. Conodonts: those fascinating little whatzits. Journal of Paleontology 59: 485494.Google Scholar
Teaford, M. F. 1988. Scanning electron microscope diagnosis of wear patterns versus artefacts on fossil teeth. Scanning Microscopy 2: 11671175.Google Scholar
Voges, A. 1959. Conodonten aus dem Untercarbon I und II (Gattendorfia-und Pericyclus-Stufe) des Sauerlandes. Pala¨ontologische Zeitschrift 33: 266314.Google Scholar
von Bitter, P. H. 1972. Environmental control of conodont distribution in the Shawnee Group (Upper Pennsylvanian) of eastern Kansas. University of Kansas Paleontological Contributions 59: 1105.Google Scholar
Weddige, K. 1990. Pathological conodonts. Courier Forschungsinstitut Senckenberg 118: 563589.Google Scholar
Wild, R. 1978. Die Flugsaurier (Reptilia, Pterosauria) aus der Oberen Trias von Cene bei Bergamo, Italien. Bollettino della Societa Paleontographica Italiana 17: 176256.Google Scholar
Wu, X.-C., Sues, H.-D., and Sun, A. 1995. A plant-eating crocodyliform reptile from the Cretaceous of China. Nature 376: 678680.Google Scholar
Young, J. Z. 1978. Programs of the brain. Oxford University Press, Oxford.Google Scholar
Zhang, S., Aldridge, R. J., and Donoghue, P. C. J. 1997. An Early Triassic conodont with periodic growth?. Journal of Micropalaeontology 16: 6572.Google Scholar