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The masticatory apparatus of the armadillo Eutatus (Mammalia, Cingulata) and some allied genera: paleobiology and evolution

Published online by Cambridge University Press:  20 May 2016

Sergio F. Vizcaíno
Affiliation:
Departamento Científico Paleontología de Vertebrados, Museo de La Plata. Paseo del Bosque s/n, 1900 La Plata, Argentina. E-mail: [email protected]
María S. Bargo
Affiliation:
Departamento Científico Paleontología de Vertebrados, Museo de La Plata. Paseo del Bosque s/n, 1900 La Plata, Argentina. E-mail: [email protected]

Abstract

The eutatines are a group of fossil armadillos traditionally regarded as herbivorous due to the particular morphology of the skull and teeth. Nevertheless, they have never been the subject of a detailed morpho-functional analysis. The masticatory apparatus of Eutatus (late Pliocene–early Holocene) is analyzed and compared with other eutatines (Proeutatus and Stenotatus from the Miocene, and Doellotatus and Ringueletia from the Pliocene) and with living armadillos (Euphractus and Dasypus). The masticatory muscles were reconstructed from origin and insertion scars; the occlusal pattern and mandibular movements were determined through the study of the craniomandibular joint, the shape and arrangement of the teeth and the symphysis, and the moment arms of the lines of action of the masseter and temporalis muscles were estimated. Skull and mandible shapes were compared using the Procrustean method Resistant-Fit Theta-Rho-Analysis (RFTRA). The analysis of the masticatory apparatus of the eutatines allows us to state that Eutatus and Proeutatus exhibit the most specialized morphology known for an herbivore with an armadillo-like skull pattern. Additionally, we can identify a morphological group from the Miocene Stenotatus to the Pleistocene Eutatus, including the Pliocene Doellotatus and Ringueletia as intermediate stages of a morphological line; Proeutatus deviates from this pattern. This morphological separation may reflect an early dichotomy within the well-defined clade of eutatines.

Type
Articles
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Benson, R. H., Chapman, R. E., and Siegel, A. F. 1982. On the measurement of morphology and its change. Paleobiology 8: 328339.CrossRefGoogle Scholar
Chapman, R. E. 1990a. Conventional Procrustes approaches. F. J. Rohlf, F. L. Bookstein. Proceedings of the Michigan Morphometrics Workshop. University of Michigan Museum of Zoology Special Publication. 2: 251267.Google Scholar
Chapman, R. E. 1990b. Shape analysis in the study of dinosaur morphology. Pp. 2142. in Carpenter, K., Currie, P. J. eds. Dinosaur systematics: perspectives and approaches Cambridge University Press, Cambridge.Google Scholar
Edmund, G. 1985. The fossil giant armadillos of North America (Pampatheriinae, Xenarthra =Edentata). pp. 8393in Montgomery 1985.Google Scholar
Engelmann, G. F. 1985. The phylogeny of the Xenarthra. pp. 5164in Montgomery 1985.Google Scholar
Fariña, R. A. 1985. Some functional aspects of mastication in Glyptodontidae (Mammalia). Fortschritte der Zoologie 30: 277280.Google Scholar
Fariña, R. A. 1988. Observaciones adicionales sobre la biomecánica masticatoria en Gliptodontidae (Mammalia; Edentata). Boletín de la Sociedad Zoológica (2a. época) 4: 59. Montevideo.Google Scholar
Fariña, R. A. and Vizcaíno, S. F. 1995. Hábitos locomotores del armadillo pleistoceno Propraopus grandis (Mammalia, Dasypodidae): una comparación con formas actuales. VI Congreso Argentino de Paleontología y Bioestratigrafía, Actas: 123127.Google Scholar
Fariña, R. A. and Vizcaíno, S. F. 1997. Allometry of the leg bones in armadillos (Mammalia, Dasypodidae). A comparison with other mammals Zeitschrift für Säugetierkunde. 62: 6570.Google Scholar
Gillette, D. D. and Ray, C. E. 1981. Glyptodonts of North America. Smithsonian Contributions to Paleobiology 40: 1251.Google Scholar
Greaves, W. S. 1973. The inference of jaw motion from tooth wear facets. Journal of Paleontology 47: 10001001.Google Scholar
Greaves, W. S. 1978. The jaw lever system in ungulates: a new model. Journal of Zoology 184: 271285.Google Scholar
Grimm, R. 1970. Blauböckchen (Cephalophus monticola (Thunberg, 1798); Cephalophinae, Bovidae) als Insektenfresser. Zeitschrift für Säugetierkunde 35: 357359.Google Scholar
Hiiemae, K. M. and Crompton, A. W. 1985. Mastication, food transport and swallowing. Pp. 262290. Hildebrand, M., Bramble, D., Liem, K., Wake, D.Functional vertebrate morphology Belknap Press, Harvard University Press, Cambridge.Google Scholar
Hoffstetter, R. 1958. Xenarthra. Pp. 535636. Piveteau, J.Traité de Paléontologie, Tome 6, Vol. 2. Masson et Cie, Paris.Google Scholar
Jarman, P. J. 1974. The social organisation of antelope in relation to their ecology. Behaviour 48: 215267.Google Scholar
Kurt, F. 1963. Zur Carnivorie bei Cephalophus dorsalis. Zeitschrift für Säugetierkunde 28: 309313.Google Scholar
Lydekker, R. 1894. Contributions to a knowledge of the fossil vertebrates of Argentina, Part II. The extinct edentates of Argentina Anales del Museo de La Plata (Paleontología Argentina). 3: 1118.Google Scholar
Macalister, A. 1869. On the myology of Bradypus tridactylus; with remarks on the general anatomy of the Edentata. Annual Magazine of Natural History 4: 5167.Google Scholar
Smith, J. Maynard and Savage, R. J. G. 1959. The mechanics of mammalian jaws. School of Sciences Review 141: 289301.Google Scholar
Montgomery, G. G. 1985. The evolution and ecology of armadillos, sloths and vermilinguas. Smithsonian Institution Press, Washington, D.C.Google Scholar
Naples, V. L. 1987. Reconstruction of cranial morphology and analysis of function in Nothrotheriops shastense. Los Angeles County Museum of Natural History Contributions in Science 389: 121.Google Scholar
Naples, V. L. 1989. The feeding mechanism in the Pleistocene ground sloth, Glossotherium. Los Angeles County Museum of Natural History Contributions in Science 415: 123.Google Scholar
Nowak, R. M. and Paradiso, J. L. 1983. Walker's mammals of the world, 4th ed.Johns Hopkins University Press, Baltimore.Google Scholar
Redford, K. H. 1985. Food habits of armadillos (Xenarthra: Dasypodidae). pp. 429437in Montgomery 1985.Google Scholar
Scillato-Yané, G. J. 1980. Catálogo de los Dasypodidae fósiles (Mammalia, Edentata) de la República Argentina. II Congreso Argentino de Paleontología y Bioestratigrafía y I Congreso Latinoamericano de Paleontología, Actas 3: 736.Google Scholar
Scillato-Yané, G. J. 1982. Los Dasypodidae (Mammalia, Edentata) del Plioceno y Pleistoceno de Argentina. Ph.D. dissertation. Universidad Nacional de La Plata, La Plata, Argentina.Google Scholar
Scott, W. B. 1903. 1904. Mammalia of the Santa Cruz beds. I. Edentata. Pp. 1364. in Scott, W. B. ed. Reports of the Princeton University expeditions to Patagonia 1896-1899. Princeton University Press, Princeton, N.J.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. K. eds. The skull—functional and evolutionary mechanisms, Vol. 3. University of Chicago Press, Chicago.Google Scholar
Smith, K. K. and Redford, K. H. 1990. The anatomy and function of the feeding apparatus in two armadillos (Dasypoda): anatomy is not destiny. Journal of Zoology 222: 747.Google Scholar
Turnbull, W. D. 1970. Mammalian masticatory apparatus. Fieldiana (Geology) 18: 149356.Google Scholar
Vizcaíno, S. F. and Fariña, R. A. 1994. Caracterización trófica de los armadillos (Mammalia, Xenarthra, Dasypodidae) de Edad Santacrucense (Mioceno temprano) de Patagonia (Argentina). Acta Geológica Leopoldensia 39/1(XVII): 191200.Google Scholar
Vizcaíno, S. F. and Fariña, R. A. 1997. Diet and locomotion in the armadillo Peltephilus: a new view. Lethaia 30: 7986.Google Scholar
Winge, H. 1941. Edentates (Edentata). Pp. 319341. in Jensen, S., Spärck, R., Volsoe, H. eds. The interrelationships of the Mammalia genera. Reitzels, Copenhagen.Google Scholar