Abstract
A conspicuous synapomorphy of the marsupial genus Didelphis is the hypertrophied spinous process of cervical vertebrae (C). The tall, thick spinous processes of C2 to C6 interlock preventing any movement of the neck. A functional interpretation of this structure has been elusive. On the basis of osteological specimens of D. albiventris and D. virginiana, we propose a possible function. These specimens show large, partially healed wounds in the spinous processes, indicating that the specimens survived major traumatisms probably caused by carnivorans, so that the spinous processes may have acted as neck armor. Didelphis exhibits several other, well-known defensive traits which, in combination with generalized feeding and locomotor habits, altogether may have helped the lineage survive the Late Tertiary extinction waves in South America and the Great American Biotic Interchange.
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References
Argot, C., 2003. Functional-adaptative anatomy of the axial skeleton of some extant marsupials and the paleobiology of the Paleocene marsupials Mayulestes ferox and Pucadelphys andinus. Journal of Morphology 255, 279–300.
Biknevicius, A.R., Van Valkenburgh, B., 1996. Design for killing: craniodental adaptations of predators. In: Gittleman, J.L. (Ed.), Carnovore Behavior, Ecology and Evolution, vol. 2. Cornell University Press, Ithaca/London, pp. 393–428.
Cerqueira, R., Tribe, C., 2007. Genus Didelphis. In: Gardner, A. (Ed.), Mammals of South America, vol. 1. The University of Chicago Press, pp. 17–25.
Charles-Dominique, P., Atramentowicz, M., Charles-Dominique, M., Gerard, H., Hladik, A., Hladik, C.M., Prevost, M.F., 1981. Les mammifères arboricoles frugivores nocturnes d’une forêt guyanaise: inter-relations plantes-animaux. Revue D Ecologie (Terre Vie) 35, 341–435.
Coues, E., 1869. The osteology and myology of Didelphyidae Didelphis virginiana. Memories of the Boston Society of Natural History 2, 41–149.
Cozzuol, M.A., Goin, F., de los Reyes, M., Ranzi, A., 2006. The oldest species of Didelphis (Mammalia, Marsupialia, Didelphidae) from the late Miocene of Amazonia. Journal of Mammalogy 87, 663–667.
Crompton, A.W., Hylander, W., 1986. Changes in mandibular function following the acquisition of a dentary—squamosal jaw articulation. In: Hotton III, N., MacLean, P.D., Roth, J.J., Roth, E.C. (Eds.), The Ecology and Biology of Mammal-like Reptiles. Smithsonian Institution Press, Washington, DC, pp. 263–282.
Ewer, R.F., 1973. The Carnivores. Cornell University Press, New York.
Fitch, H.S., Shirer, H.W., 1970. A radiotelemetric study ofspatial relationships in the opossum. American Midland Naturalist 84, 170–186.
Flores, D.A., 2009. Phylogenetic analyses ofpostcranial skeletal morphologyin didelphid marsupials. Bulletin of the American Museum of Natural History 320, 1–81.
Forasiepi, A.M., Martinelli, A.G., Goin, F.J., 2007. Revisión taxonómica de Parahyaenodon argentinus Ameghinoy sus implicancias en el conocimiento de los grandes mamíferos carnívoros del Mio-Plioceno de América de Sur. Ameghiniana 44, 143–159.
Gardner, A., 2005. Order Didelphimorphia. In: Wilson, D.E., Reeder, M. (Eds.), Mammals Species of the World. John Hopkins University Press, Baltimore, pp. 3–18.
Kirsch, J.A.W., Blerweiss, R.E., Dickerman, A.W., Reig, O.A., 1993. DNA/DNA hybridization studies of carnivorous marsupials III. Relationships among species of Didelphis (Didelphidae). Journal of Mammalian Evolution 1, 75–97.
MacDonald, D.W., Kays, R.W., 2005. Carnivores of the world: an introduction. In: Nowak, R.M. (Ed.), Walker’s Carnivores of the World. The John Hopkins University Press, Baltimore/London, pp. 1–67.
Marshall, L.G., 1987. Systematics of Itaboraian (middle Paleocene) age ‘opossumlike’ marsupials from the limestone quarry at Sao José de Itaborai, Brasil. In: Archer, M. (Ed.), Possums and Opossums: Studies in Evolution, vol. 1. Surrey Beatty & Sons, Sydney, Australia, pp. 91–160.
McManus, J.J., 1974. Didelphis virginiana. Mammalian Species 40, 1–6.
Patton, J.L., Costa, L.P., 2003. Molecular phylogeography and species limits in rainforest didelphid marsupials of South America. In: Jones, M.E., Dickman, C.R., Archer, M. (Eds.), Predators with Pouches: The Biology of Carnivorous Marsupials. CSIRO Publishing, Collingwood, Australia, pp. 63–81.
Reig, O.A., 1981. Teoría del origen y desarrollo de la fauna de mamíferos de América del Sur. Monografías del Museo Municipal de Ciencias Naturales Lorenzo Scaglia, 1–162.
Reig, O.A., Kirsch, J.A.W., Marshall, L.G., 1987. Systematic relationships of the living and neocenozoic american “opossum-like” marsupials (Suborder Didelphimorphia) with comments on the classification of these and of the cretaceous and paleogene New World and european metatherians. In: Archer, M. (Ed.), Possums and Opossums: Studies in Evolution, vol. 1. Surrey Beatty & Sons, Sydney, Australia, pp. 1–89.
Soibelzon, L.H., Prevosti, F.J., 2007. Los carnívoros (Carnivora, Mammalia) terrestres del Cuaternario de América del Sur. In: Pons, G.X., Vicens, D. (Eds.), Geomorfología Litoral i Quaternari. Homenatge a Joan Cuerda Barceló. Monografia de la Societat d’Història Natural, Palma de Mallorca, pp. 49–68.
Vrba, E.S., 1992. Mammals as a key to evolutionary theory. Journal of Mammalogy 73, 1–28.
Woodburne, M., Cione, A.L., Tonni, E.P., 2006. Central American provincialism and the Great American Biotic Interchange. In: Carranza-Castañeda, O., Lindsay, E.H. (Eds.), Advances in Late Tertiary Vertebrate Paleontology in Mexico and the Great American Biotic Interchange. Publicación Especial del Instituto de Geología y Centro de Geociencias de la Universidad Nacional Autónoma de México 4, México, DF, pp. 73–101.
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Giannini, N.P., Gaudioso, P., Flores, D.A. et al. A possible function for an enigmatic synapomorphy of Didelphis. Mamm Biol 76, 512–514 (2011). https://doi.org/10.1016/j.mambio.2010.06.001
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DOI: https://doi.org/10.1016/j.mambio.2010.06.001