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Gross spinal anatomy and limb use in living and fossil reptiles

Published online by Cambridge University Press:  08 April 2016

Emily B. Giffin
Emily B. Giffin*
Affiliation:
Department of Biology, Wellesley College, Wellesley, Massachusetts 02181
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Abstract

The spinal quotient (S.Q.) is an osteologically defined estimate of the enlargement of the spinal cord at limb levels over that at interlimb levels. It is an efficient predictor of limb use in living reptiles and birds and may be used to predict limb function in fossil vertebrates. Among living reptiles, this ratio of limb to interlimb innervation is greatest in arboreal genera, followed by terrestrial sprawlers, aquatic forms, and undulatory forms. Birds show a wide range of brachial S.Q. values that are roughly commensurate with flight ability. S.Q. values for the manipulative forelimbs of some dinosaurs fall well above those of locomotory limbs. Dinosaur hind-limb values are either well within ranges predicted by living reptiles and birds (most taxa), or highly inflated (stegosaurs, sauropods). This inflation may be the result of presence of a glycogen body similar to that of birds. In no case does the lumbosacral S.Q. support the presence of a “sacral brain.”

Type
Research Article
Information
Paleobiology , Volume 16 , Issue 4 , Fall 1990 , pp. 448 - 458
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Alexander, R. McN. 1985. Dynamics of Dinosaurs and Other Extinct Giants. Columbia University Press; New York.Google Scholar
Ariens Kappers, C. U., Huber, G. C., and Crosby, E. C. 1936. The Comparative Anatomy of the Nervous System of Vertebrates, Including Man. Macmillan; New York.Google Scholar
Auffenberg, W. 1962. A review of the trunk musculature in the limbless land vertebrates. American Zoologist 2:183–190.CrossRefGoogle Scholar
Bakker, R. T. 1987. The return of the dancing dinosaurs. Pp. 38–69. In Czerkas, S., and Olson, E. (eds.), Dinosaurs Past and Present, Volume 1. University of Washington Press; Seattle.Google Scholar
Bellairs, A. 1970. The Life of Reptiles. Universe Books; New York.Google Scholar
Benzo, C. A., and De Gennaro, L. D. 1983. An hypothesis of function for the avian glycogen body: a novel role for glycogen in the central nervous system. Medical Hypotheses 10:69–76.Google Scholar
Branca, W. 1916. Das sogennante Sacralgehirn der Dinosaurier. Archiv für Biontologie 4:131–134.Google Scholar
Coombs, W. P. 1978. Theoretical aspects of cursorial adaptations in dinosaurs. Quarterly Review of Biology 53:393–418.Google Scholar
Cruce, W. L. R. 1979. Spinal cord in lizards. Pp. 111–131. In Gans, C., Northcutt, R. G., and Ulinski, P. (eds.), Biology of the Reptilia, Volume 10. Academic Press; London.Google Scholar
Dawson, W. R., Bartholomew, G. A., and Bennett, A. F. 1977. A reappraisal of the aquatic specializations of the Galapagos marine iguana (Amblyrhynchus cristatus). Evolution 31:891–897.Google Scholar
De Gennaro, L. D. 1982. The glycogen body. Avian Biology 6:341–371.Google Scholar
Dodson, P. 1975. Functional and ecological significance of relative growth in Alligator. Journal of Zoology, London 175:315–355.Google Scholar
Frey, E. 1988. Das Tragsystem der Krocodile—eine biomechanische und phylogenetische Analyse. Stuttgarter Beitrage zur Naturkunde Serie A (Biologie) 426:1–60.Google Scholar
Gans, C. 1975. Tetrapod limblessness: evolution and functional corollaries. American Zoologist 15:455–467.Google Scholar
Gilmore, C. W. 1914. Osteology of the armored Dinosauria in the United States National Museum, with special reference to the genus Stegosaurus. Bulletin of the United States National Museum 89:1–143.Google Scholar
Gilmore, C. W. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300.Google Scholar
Hatcher, J. B., Marsh, O. C., and Lull, R. S. 1907. The Ceratopsia. United States Geological Survey Monograph 49:1–196.Google Scholar
Hopson, J. A. 1977. Relative brain size and behavior in archosaurian reptiles. Annual Review of Ecology and Systematics 8:429–448.Google Scholar
Hopson, J. A. 1979. Paleoneurology. Pp. 39–146. In Gans, C., Northcutt, R. G., and Ulinski, P. (eds.), Biology of the Reptilia, Volume 9. Academic Press; New York.Google Scholar
Huber, J. F. 1936. Nerve roots and nuclear groups in the spinal cord of the pigeon. Journal of Comparative Neurology 65:43–91.Google Scholar
Imhof, G. 1905. Anatomie und Entwicklungsgeschichte des Lumbalmarkes bei den Vogeln. Archiv für Mikroskopische Anatomie und Entwicklungsgeschichte 65:498–610.Google Scholar
Janensch, W. 1939. Der sakrale Neuralkanal einiger Sauropoden und anderer Dinosaurier. Palaontologische Zeitschrift 21:171–193.Google Scholar
Jenkins, F. A. Jr., and Parrington, F. R. 1976. The postcranial skeletons of the Triassic mammals Eozostrodon, Megazostrodon and Erythrotherium. Philosophical Transactions of the Royal Society of London B. 273:387–431.Google Scholar
Jenkins, F. A. Jr., and Goslow, G. E. 1983. The functional anatomy of the shoulder of the Savannah monitor lizard (Varanus exanthematicus). Journal of Morphology 175:195–216.Google Scholar
Jerison, H. J. 1973. Evolution of the Brain and Intelligence. Academic Press; New York.Google Scholar
Krause, W. 1881. Zum Sacralhirn der Stegosaurier. Biologisches Zentralblatt 1:461.Google Scholar
Kusuma, A., ten Donkelaar, H. J., and Nieuwenhuys, R. 1979. Intrinsic Organization of the spinal cord. Pp. 59–109. In Gans, C., Northcutt, R. G., and Ulinski, P. (eds.), Biology of the Reptilia, Volume 10. Academic Press; London.Google Scholar
Lull, R. S. 1917. On the functions of the “sacral brain” in dinosaurs. American Journal of Science, 4th Series 44:471–477.CrossRefGoogle Scholar
Lull, R. S. 1933. A revision of the Ceratopsia, or horned dinosaurs. Memoirs of the Peabody Museum of Natural History 3:1–135.Google Scholar
Madsen, J. H. 1976. Allosaurus fragilis: a revised osteology. Bulletin of the Utah Geological and Mineralogical Survey 109:1–163.Google Scholar
Marsh, O. C. 1880. Odontornithes, a monograph of the extinct toothed birds of North America. Report of the Geological Explorations of the 40th Parallel 7:1–201.Google Scholar
Marsh, O. C. 1896. The Dinosaurs of North America. United States Geological Survey, Annual Report 16:143–414.Google Scholar
Mattison, R. G., and Giffin, E. B. 1989. Limb use and disuse in ratites and tyrannosaurids. Journal of Vertebrate Paleontology, Abstracts of Papers 9:32A.Google Scholar
Nieuwenhuys, R. 1964. Comparative anatomy of the spinal cord. Progress in Brain Research 11:1–57.Google Scholar
Ohmori, Y., Watanabe, T., and Fujioka, T. 1982. Localization of the motoneurons innervating the forelimb muscles in the spinal cord of the domestic fowl. Zentralblatt für Veterinaermedizin C: Anatomie, Histologie, Embryologie 11:124–137.Google Scholar
Ohmori, Y., Watanabe, T., and Fujioka, T. 1984. Localization of the motoneurons innervating hindlimb muscles in the spinal cord of the domestic fowl. Zentralblatt für Veterinaermedizin C: Anatomie, Histologie, Embryologie 13:141–155.Google Scholar
Ostrom, J. H. 1969. Osteology of Deinonychus antirropus, an unusual theropod from the Lower Cretaceous of Montana. Bulletin of the Peabody Museum of Natural History 30:1–165.Google Scholar
Ostrom, J. H. 1973. The ancestry of birds. Nature 242:136.Google Scholar
Parrish, J. M. 1987. The origin of crocodilian locomotion. Paleobiology 13:396–414.Google Scholar
Peterson, J. A. 1984. The locomotion of Chamaeleo (Reptilia: Sauria) with particular reference to the forelimb. Journal of Zoology, London 202:1–42.Google Scholar
Raikow, R. J. 1985. Locomotor system. Pp. 57–148. In King, A. S., and McLelland, J. (eds.), Form and Function in Birds, Volume 3. Academic Press; London.Google Scholar
Raynaud, A. 1985. Development of limbs and embryonic limb reduction. Pp. 59–148. In Gans, C., and Billett, F. (eds.), Biology of the Reptilia, Volume 15. Wiley-Interscience; New York.Google Scholar
Schmidt-Nielsen, K. 1972. How Animals Work. Cambridge University Press; Cambridge.CrossRefGoogle Scholar
Seeley, H. G. 1882. On Thecospondylus horneri, a new dinosaur from the Hastings sand, indicated by the sacrum and the neural canal of the sacral region. Quarterly Journal of the Geological Society of London 1882:457–460.Google Scholar
Seymour, R. S. 1982. Physiological adaptations to aquatic life. Pp. 1–51. In Gans, C., and Pough, F. H. (eds.), Biology of the Reptilia, Volume 13. Academic Press; London.Google Scholar
Smith, M. A. 1935. The Fauna of British India, including Ceylon and Burma. Volume II: Sauria. Taylor and Francis; London.Google Scholar
Snyder, R. C. 1949. Bipedal locomotion of the lizard Basiliscus basiliscus. Copeia 2:129–137.Google Scholar
Snyder, R. C. 1962. Adaptations for bipedal locomotion of lizards. American Zoologist 2:191–203.Google Scholar
Streeter, G. L. 1904. The structure of the spinal cord of the ostrich. American Journal of Anatomy 3:1–27.Google Scholar