Journal of Mammalian Evolution

, Volume 1, Issue 1, pp 31–46 | Cite as

New ontogenetic evidence on the septomaxilla ofTamandua andCholoepus (Mammalia, Xenarthra), with a reevaluation of the homology of the mammalian septomaxilla

  • U. Zeller
  • J. R. Wible
  • M. Elsner
Article

Abstract

An intramembranous ossification at the anterior end of the cartilaginous nasal capsule is described for the first time in prenatal specimens of the anteaterTamandua and the slothCholoepus and redescribed in prenatal specimens of the armadillosDasypus andZaedyus. From comparisons of this bone with the septomaxilla of monotremes and various Mesozoic mammals, it is concluded that (1) the bone inTamandua andCholoepus is homologous with the central part (processus ascendens) of the bone inDasypus, Zaedyus, and other armadillos and (2) the xenarthran processus ascendens, in turn, is homologous with the central part of the septomaxilla of monotremes and various Mesozoic mammals. Therefore, the bone in question in xenarthrans is a true septomaxilla. It is further concluded that the armadillo septomaxilla has two neomorphic components: a lamina palatina beneath the cartilaginous nasal floor and a processus intrafenestralis extending rostrally into the nasal fossa.

Key words

septomaxilla Xenarthra Monotremata ontogeny phylogenetic reconstruction 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature cited

  1. Bonaparte, J. F., and Rougier, G. (1987). Mamiferos del Cretacico inferior de Patagonia.IV Congr. Latinoam. Paleontol. Bolivia 1 343–359.Google Scholar
  2. Crompton, A. W., and Luo, Z. (1993). Relationships of the Liassic mammals,Sinoconodon, Morganucodon oehleri, andDinnetherium. InMammal Phylogeny, Vol. 1, F. S. Szalay, M. J. Novacek, and M. C. McKenna, eds., Springer Verlag, New York (in press).Google Scholar
  3. De Beer, G. R. (1937).The Development of the Vertebrate Skull, Clarendon Press, Oxford.Google Scholar
  4. De Beer, G. R., and Fell, W. A. (1936). The development of the Monotremata. III. The development of the skull ofOrnithorhynchus.Trans. Zool. Soc. Lond. 23 1–43.Google Scholar
  5. Engelmann, G. F. (1985). The phylogeny of the Xenarthra. InThe Evolution and Ecology of Armadillos, Sloths, and Vermilinguas, G. Montgomery, ed., pp. 51–64, Smithsonian Institution Press, Washington, D.C.Google Scholar
  6. Fawcett, E. (1919). The os septo-maxillare ofTatusia novemcincta.J. Anat. 53 349–350.Google Scholar
  7. Fawcett, E. (1921). The primordial cranium ofTatusia novemcincta as determined by sections and models of the embryos of 12 millimetre and 17 millimetre c.r. length.J. Anat. 55 187–217.Google Scholar
  8. Fuchs, H. (1911). Ueber das Septomaxillare eines rezenten Säugetieres (Dasypus), nebst einigen vergleichend-anatomischen Bemerkungen über das Septomaxillare und Praemaxillare der Amnioten überhaupt.Anat. Anz. 38 33–55.Google Scholar
  9. Gaupp, E. (1905). Neue Deutungen auf dem Gebiete der Lehre vom Säugetierschädel.Anat. Anz. 27 273–310.Google Scholar
  10. Gaupp, E. (1908). Zur Entwickelungsgeschichte und vergleichenden Morphologie des Schädels vonEchidna aculeata var. typica.Semon. Zool. Forschungsreisen in Australien. Denkschr. med. naturwiss. Ges. Jena 6(2): 539–788.Google Scholar
  11. Gauthier, J., Kluge, A. G., and Rowe, T. (1988). Amniote phylogeny and the importance of fossils.Cladistics 4 105–209.Google Scholar
  12. Goodrich, E. S. (1930).Studies on the Structure and Development of Vertebrates, Macmillan, London.Google Scholar
  13. Green, H. L. (1930). A description of the egg tooth ofOrnithorhynchus, together with some notes on the development of the palatine processes of the praemaxillae.J. Anat. 64 512–522.Google Scholar
  14. Hoffstetter, R. (1958). Xenarthra. InTraité de Paléontologie, J. Piveteau, ed., pp. 535–636, Masson and Cie, Paris.Google Scholar
  15. Hopson, J. A. (1991). Systematics of non-mammalian Synapsida and implications for patterns of evolution in synapsids. InOrigins of the Higher Groups of Tetrapods: Controversy and Consensus, H.-P. Schultze and L. Trueb, eds., pp. 635–693, Comstock, Ithaca, NY.Google Scholar
  16. Hopson, J. A., and Barghusen, H. R. (1986). An analysis of therapsid relationships. InThe Ecology and Biology of Mammal-like Reptiles, N. Hotton III, P. D. MacLean, J. J. Roth, and E. C. Roth, eds., pp. 83–106, Smithsonian Institution Press, Washington, D.C.Google Scholar
  17. Jollie, M. (1968). The head skeleton of a new-bornManis javanica with comments on the ontogeny and phylogeny of the mammal head skeleton.Acta Zool. 49 227–305.Google Scholar
  18. Kermack, K. A., Mussett, F., and Rigney, H. W. (1981). The skull ofMorganucodon.Zool. J. Linn. Soc. 71 1–158.Google Scholar
  19. Kuhn, H.-J. (1971). Die Entwicklung und Morphologie des Schädels vonTachyglossus aculeatus.Abh. senckenberg. naturforsch. Ges. 528 1–224.Google Scholar
  20. Kuhn, H.-J. (1987). Introduction. InMorphogenesis of the Mammalian Skull, H.-J. Kuhn and U. Zeller, eds.,Mammalia depicta Vol. 13, pp. 9–15, Paul Parey, Hamburg.Google Scholar
  21. Novacek, M. J. (1992). Mammalian phylogeny: Shaking the tree.Nature 356 121–125.Google Scholar
  22. Novacek, M. J., Wyss, A. R., and McKenna, M. C. (1988). The major groups of eutherian mammals. InThe Phylogeny and Classification of Tetrapods, Vol. 2. Mammals, M. J. Benton, ed., pp. 31–71, Clarendon Press, Oxford.Google Scholar
  23. Patterson, C. (1982). Morphological characters and homology. InProblems of Phylogenetic Reconstruction, K. A. Joysey and A. E. Friday, eds., pp. 21–74, Academic Press, London.Google Scholar
  24. Presley, R., and Steel, F. L. D. (1978). The pterygoid and ectopterygoid in mammals.Z. Anat. Embryol. 154 95–110.Google Scholar
  25. Reinbach, W. (1952a). Zur Entwicklung des Primordialcraniums vonDasypus novemcinctus Linné (Tatusia novemcincta Lesson) I.Z. Morph. Anthropol. 44 375–444.Google Scholar
  26. Reinbach, W. (1952b). Zur Entwicklung des Primordialcraniums vonDasypus novemcinctus Linné (Tatusia novemcincta Lesson) II.Z. Morph. Anthropol. 45 1–72.Google Scholar
  27. Reinbach, W. (1955). Das Cranium eines Embryos des GürteltieresZaedyus minutus (65 mm Sch.-St.).Morph. Jb. 95 79–141.Google Scholar
  28. Remane, A. (1952).Die Grundlagen des natürlichen Systems, der vergleichenden Anatomie und Phylogenetik, Geest & Portig, Leipzig.Google Scholar
  29. Schneider, R. (1955). Zur Entwicklung des Chondrocranium der GattungBradypus. Morph. Jb. 95 209–301.Google Scholar
  30. Stadtmüller, F. (1936). Kranium und Visceralskelett der Säugetiere. InHandbuch der vergleichenden Anatomie der Wirbeltiere, L. Bolk, E. Göppert, E. Kallius, and W. Lubosch, eds., Vol. 4, pp. 839–1016, Urban and Schwarzenberg, Berlin and Wien.Google Scholar
  31. Starck, D. (1941). Zur Morphologie des Primordialkraniums vonManis javanica Desm.Morph. Jb. 86 1–122.Google Scholar
  32. Starck, D. (1967). Le crâne des mammifères. InTraité de Zoologie, P. Grassé, ed., Vol. 16(1), pp. 405–549, 1095–1102, Masson and Cie, Paris.Google Scholar
  33. Stevens, P. F. (1984). Homology and phylogeny: Morphology and systematics.Syst. Botany 9 395–409.Google Scholar
  34. Sturm, H. (1937). Die Entwicklung des praecerebralen Nasenskeletts beim Schwein (Sus scrofa domestica) und bei Rind (Bos taurus).Z. wiss. Zool. 149 161–220.Google Scholar
  35. Wegner, R. N. (1922). Der Stützknochen, Os nariale, in der Nasenhöhle bei den Gürteltieren, Dasypodidae, und seine homologen Gebilde bei Amphibien, Reptilien und Monotremen.Morph. Jb. 51 413–492.Google Scholar
  36. Wegner, R. N. (1950). Unterschiede der Nasenlochgestaltung und des Os nariale bei den Säugetieren (Choloepus) und den Bauriamorphen.Verh. Anat. Ges. 28 104–111.Google Scholar
  37. Wible, J. R. (1991). Origin of Mammalia: The craniodental evidence reexamined.J. Vert. Paleontol. 11 1–28.Google Scholar
  38. Wible, J. R., Miao, D., and Hopson, J. A. (1990). The septomaxilla in fossil and Recent synapsids and the problem of the septomaxilla of monotremes and armadillos.Zool. J. Linn. Soc. 98 203–228.Google Scholar
  39. Zeller, U. (1987). Morphogenesis of the mammalian skull with special reference toTupaia. InMorphogenesis of the Mammalian Skull, H.-J. Kuhn and U. Zeller, eds.,Mammalia depicta, Vol. 13, pp. 17–50, Paul Parey, Hamburg.Google Scholar
  40. Zeller, U. (1988). The Lamina cribrosa ofOrnithorhynchus (Monotremata, Mammalia).Anat. Embryol. 178 513–519.Google Scholar
  41. Zeller, U. (1989). Die Entwicklung und Morphologie des Schädels vonOrnithorhynchus anatinus (Mammalia: Prototheria: Monotremata).Abh. senckenberg. naturforsch. Ges. 545 1–188.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • U. Zeller
    • 1
  • J. R. Wible
    • 2
  • M. Elsner
    • 1
  1. 1.Abteilung Morphologie, Zentrum AnatomieUniversität GöttingenGöttingenFRG
  2. 2.Department of Anatomical Sciences and Neurobiology, School of MedicineUniversity of LouisvilleLouisville

Personalised recommendations