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Dinosaur Monophyly and a New Class of Vertebrates

Nature volume 248, pages 168172 (08 March 1974) | Download Citation

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Abstract

TRADITIONALLY dinosaurs are classified as two or three separate, independent groups of reptiles in the Subclass Archosauria. But evidence from bone histology, locomotor dynamics, and predator/prey ratios strongly suggest that dinosaurs were endotherms with high aerobic exercise metabolism, physiologically much more like birds and cursorial mammals than any living reptiles1–8. Recently Ostrom has argued forcefully that birds are direct descendants of dinosaurs and inherited high exercise metabolism from dinosaurs1,8. Here we present evidence that dinosaurs are a single, monophyletic group, and that the key advancements of endothermy and high exercise metabolism are justification for removing dinosaurs from the Reptilia and placing them with birds in a new class, the Dinosauria.

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References

  1. 1.

    , Q. Rev. Biol. (in the press, 1974).

  2. 2.

    , in Perspectives of Biophysical Ecology (edit. by Gates, D., and Schmerl, R. B.) (New York, in the press).

  3. 3.

    , and , Tex. J. Sci., 2, 186 (1957).

  4. 4.

    , Palaeontology, 5, 238 (1962).

  5. 5.

    , Annls. Paleont., 54, 9 (1968).

  6. 6.

    , Evolution, 25, 363 (1971).

  7. 7.

    , Nature, 238, 81 (1972).

  8. 8.

    , Nature, 242 136 (1973).

  9. 9.

    , Proc. Pap. 2nd Gond. Symp. S. Afr., 665 (Council for Scientific and Industrial Research, Pretoria, 1972).

  10. 10.

    , Op. lilloana, 22, 183 (1971).

  11. 11.

    , Ameghiniana, 4, 47 (1967).

  12. 12.

    , Ameghiniana, 3, 3 (1963).

  13. 13.

    , Breviora, 389, 1 (1972).

  14. 14.

    , Nature, 234, 75 (1971).

  15. 15.

    , in Studies in Vertebrate Evolution (edit. by Joysey, K. A., and Kemp, T. S.) (Oliver and Boyd, Edinburgh, 1972).

  16. 16.

    , Mem. Inst. vertebr. Paleont. Peking, 10, 15 (1973).

  17. 17.

    , Phil. Trans. R. Soc., B, 244, 103 (1961).

  18. 18.

    , Phil. Trans. R. Soc., B, 248, 53 (1964).

  19. 19.

    , Phil. Trans. R. Soc., B, 257, 323 (1970).

  20. 20.

    , in Die Saurier der Deutschen Trias (Verglag Oeben, München, 1971).

  21. 21.

    , in Vertebrate Paleontology (University of Chicago Press, Chicago, 1967).

  22. 22.

    , , and , Proc. Linn. Soc. Lond., 176, 197 (1965).

  23. 23.

    , Breviora, 395, 1 (1972).

  24. 24.

    , in Studies in Vertebrate Evolution (edit. by Joysey, K., and Kemp, T.) (Oliver and Boyd, Edinburgh, 1972).

  25. 25.

    , J. Paleont., 21, 201 (1947).

  26. 26.

    , in Die fossilen Reptilien des Südamerikanischen Gondwanalandes (C. H. Beck'sche Verlagsbuchhandlang, München, 1935–1942).

  27. 27.

    , in Die Fahrten der Chirotheria (Jena, 1926).

  28. 28.

    , Schweiz. Palaeont. Abh., 81, 1 (1965).

  29. 29.

    , Arnoldia, 15, 1 (1971).

  30. 30.

    , Lethaia, 4, 453 (1971).

  31. 31.

    , and , Boonstra Commemorative Vol. (Cape Town, in the press).

  32. 32.

    , S. Afr. J. Sci., 59, 221 (1963).

  33. 33.

    , Bull. Mus. Comp. Zool. Harv. (in the press).

  34. 34.

    , Zoo. J. Linn. Soc., 48, 471 (1969).

  35. 35.

    , Paläont. Z., 16, 145 (1942).

  36. 36.

    , Arnoldia, 28, 1 (1969).

  37. 37.

    , Trans. zool. Soc. Lond., 29, 211 (1961).

  38. 38.

    , Amer. Mus. Novitates, 2405, 1 (1970).

  39. 39.

    , Paläont. Z., 47, 229 (1973).

  40. 40.

    , Bull. Br. Mus. nat. Hist., A, 25, 1 (1974).

  41. 41.

    , Physiologist, Lond., 15, 3 (1972).

  42. 42.

    , Breviora, 378, 1 (1971).

  43. 43.

    , Breviora, 394, 1 (1972).

  44. 44.

    , Palaeontology, 13, 414 (1970).

  45. 45.

    , J. Paleont., 45, 781 (1971).

  46. 46.

    , Syst. Ass. Pub., 3, 33 (1959).

  47. 47.

    , Lethaia, 6, 67 (1973).

  48. 48.

    , Evolution, 24, 448 (1970).

  49. 49.

    , Nature, 237, 257 (1972).

  50. 50.

    , K. ned. Akad. v. Wet., B, 75, 289 (1972).

  51. 51.

    , Am. J. Physiol., 216, 995 (1965).

  52. 52.

    , in Archaeopteryx lithographica (British Museum (Natural History), London, 1954).

  53. 53.

    , in The Origin of Birds (D. Appleton and Co., New York, 1927).

  54. 54.

    , Bull. Peabody Mus. nat. Hist., 35 (1970).

  55. 55.

    , Bull Peabody Mus. nat. Hist., 30 (1969).

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Author information

Affiliations

  1. Department of Vertebrate Paleontology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138

    • ROBERT T. BAKKER
  2. Department of Biology, University of Bridgeport, Bridgeport, Connecticut 06602

    • PETER M. GALTON

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https://doi.org/10.1038/248168a0

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