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Constraint and adaptation in the evolution of carnivoran skull shape

Published online by Cambridge University Press:  08 April 2016

Borja Figueirido ,
Norman MacLeod ,
Jonathan Krieger ,
Miquel De Renzi ,
Juan Antonio Pérez-Claros  and
Paul Palmqvist
Borja Figueirido
Affiliation:
Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga 29071, Spain. E-mail: francisco.flgueirido@uv.es
Norman MacLeod
Affiliation:
Paleontology Department, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom. E-mail: N.MacLeod@nhm.ac.uk
Jonathan Krieger
Affiliation:
Paleontology Department, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom. E-mail: J.Krieger@nhm.ac.uk
Miquel De Renzi
Affiliation:
Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Área de Paleontología, Universidad de Valencia, Apartado 22085, Valencia 46071, Spain. E-mail: Miquel.De.Renzi@uv.es
Juan Antonio Pérez-Claros
Affiliation:
Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga 29071, Spain. E-mail: johnny@uma.es
Paul Palmqvist
Affiliation:
Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga 29071, Spain. E-mail: ppb@uma.es
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Abstract

The evolutionary history of the Order Carnivora is marked by episodes of iterative evolution. Although this pattern is widely reported in different carnivoran families, the mechanisms driving the evolution of carnivoran skull morphology remain largely unexplored. In this study we use coordinate-point extended eigenshape analysis (CP-EES) to summarize aspects of skull shape in large fissiped carnivores. Results of these comparisons enable the evaluation of the role of different factors constraining the evolution of carnivoran skull design. Empirical morphospaces derived from mandible anatomy show that all hypercarnivores (i.e., those species with a diet that consists almost entirely of vertebrate flesh) share a set of traits involved in a functional compromise between bite force and gape angle, which is reflected in a strong pattern of morphological convergence. Although the paths followed by different taxa to reach this “hypercarnivore shape-space” differ because of phylogenetic constraints, the morphological signature of hypercarnivory in the mandible is remarkably narrow and well constrained. In contrast, CP-EES of cranial morphology does not reveal a similar pattern of shape convergence among hypercarnivores. This suggests a lesser degree of morphological plasticity in the cranium compared to the mandible, which probably results from a compromise between different functional demands in the cranium (e.g., feeding, vision, olfactory sense, and brain processing) whereas the mandible is only involved in food acquisition and processing. Combined analysis of theoretical and empirical morphospaces for these skull data also show the lower anatomical disparity of felids and hyaenids compared to canids and ursids. This indicates that increasing specialization within the hypercarnivorous niche may constrain subsequent morphological and ecological flexibility. During the Cenozoic, similar skull traits appeared in different carnivoran lineages, generated by similar selection pressures (e.g., toward hypercarnivory) and shared developmental pathways. These pathways were likely the proximate source of constraints on the degree of variation associated with carnivoran skull evolution and on its direction.

Type
Articles
Information
Paleobiology , Volume 37 , Issue 3 , Summer 2011 , pp. 490 - 518
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Ackerly, S. C. 1989. Kinematics of accretionary shell growth, with examples from brachiopods and molluscs. Paleobiology 15:147–164.Google Scholar
Alberch, P. 1980. Ontogenesis and morphological diversification. American Zoologist 20:653–667.CrossRefGoogle Scholar
Alberch, P. 1982. Developmental constraints in evolutionary process. Pp. 313–332 in Bonner, J. T., ed. Evolution and development. Dahlem Konferenzen, Life Sciences Research Report. Springer, New York.Google Scholar
Andersson, K. 2005. Were there pack-hunting canids in the Tertiary, and how can we know? Paleobiology 31:56–72.Google Scholar
Anton, M., Salesa, M. J., Pastor, J. F., Sanchez, I. M., Fraile, S., and Morales, J. 2004. Implications of the mastoid anatomy of larger extant felids for the evolution and predatory behavior of sabretoothed cats (Mammalia, Carnivora, Felidae). Zoological Journal of the Linnean Society 140:207–221.CrossRefGoogle Scholar
Arribas, A., and Palmqvist, P. 1999. On the ecological connection between saber-tooths and hominids: faunal dispersal events in the lower Pleistocene and a review of the evidence for the first human arrival in Europe. Journal of Archaeological Science 26:571–585.CrossRefGoogle Scholar
Barone, R. 1986. Anatomie compare des mammifères domestiques, Vol. 1. Ostéologie. Vigot, Paris.Google Scholar
Beauchamp, G., and Fernández-Juricic, E. 2004. Is there a relationship between forebrain size and group size in birds. Evolutionary Ecology Research 6:833–842.Google Scholar
Biknevicius, A. R., and Ruff, C. B. 1992. The structure of the mandibular corpus and its relationship to feeding behaviors in extant carnivorans. Journal of Zoology 228:479–507.CrossRefGoogle Scholar
Biknevicius, A. R., and Van Valkenburgh, B. 1996. Design for killing: craniodental adaptations of predators. Pp. 393–428 in Gittleman, J. L., ed. Carnivore behavior, ecology and evolution, Vol. 2. Cornell University Press, Ithaca, N.Y. Google Scholar
Biknevicius, A. R., Van Valkenburgh, B., and Walker, J. 1996. Incisor size and shape: implications for feeding behavior in sabertoothed “cats.” Journal of Vertebrate Paleontology 16:510–521.Google Scholar
Bookstein, F. L. 1991. Morphometric tools for landmarks data. Geometry and biology. Cambridge University Press, New York.Google Scholar
Bourke, J., Wroe, S., Moreno, K., McHenry, C., and Clausen, P. 2008. Effects of gape and tooth position on bite force and skull stress in the dingo (Canis lupus dingo) using a 3-dimensional finite element approach. PlosOne 3:e2200. doi:10.1371/journal. pone.0002200.CrossRefGoogle ScholarPubMed
Cardini, A., and Elton, S. 2008. Does the skull carry a phylogenetic signal? Evolution and modularity in the guenons. Biological Journal of the Linnean Society 93:813–834.CrossRefGoogle Scholar
Caumul, R., and Polly, P. D. 2005. Phylogenetic and environmental components of morphological variation: skull, mandible, and molar shape in marmots (Marmota, Rodentia). Evolution 59:2460–2472.Google ScholarPubMed
Cheverud, J. M. 1982. Phenotypic, genetic, and environmental morphological integration in the cranium. Evolution 36:499–516.Google Scholar
Cheverud, J. M., Dow, M. M., and Leutenegger, W. 1985. The quantitative assessment of phylogenetic constraints in comparative analyses: sexual dimorphism in body weight among primates. Evolution 39:1335–1351.CrossRefGoogle ScholarPubMed
Christiansen, P. 2008a. Evolution of skull and mandible shape in cats (Carnivora: Felidae). PLoS ONE 3:e2807.Google Scholar
Christiansen, P. 2008b. Evolutionary convergence of primitive sabertooth craniomandibular morphology: the clouded leopard (Neofelis nebulosa) and Paramachairodus ogygia compared. Journal of Mammalian Evolution 15:155–179.Google Scholar
Christiansen, P., and Wroe, S. 2007. Bite forces and evolutionary adaptations to feeding ecology in carnivores. Ecology 88:347–358.CrossRefGoogle ScholarPubMed
DeMaster, D. P., and Stirling, I. 1981. Ursus maritimus . Mammalian Species 145:1–7.CrossRefGoogle Scholar
De Renzi, M. 1988. Shell coiling in some larger foraminifera: general comments and problems. Paleobiology 14:387–400.CrossRefGoogle Scholar
Desdevises, Y., Legendre, P., Azouzi, L., and Morand, S. 2003. Quantifying phylogenetically structured environmental variation. Evolution 57:2647–2652.Google ScholarPubMed
Dummont, E. R., and Herrel, A. 2003. The effects of gape angle and bite point on bite force in bats. Journal of Experimental Biology 206:2117–2123.CrossRefGoogle Scholar
Eizirik, E., Murphy, W. J., Koepfli, K.-P., Johnson, W. E., Dragoo, J. W., Wayne, R. K., and O'Brien, S. J. 2010. Pattern and timing of diversification of the mammalian order Carnivora inferred from multiple nuclear gene sequences. Molecular Phylogenetics and Evolution 56:49–63.Google Scholar
Emerson, S. B., and Radinsky, L. 1980. Functional analysis of sabertooth cranial morphology. Paleobiology 6:295–312.Google Scholar
Ewer, R. F. 1973. The carnivores. Weidenfeld and Nicolson, London.Google Scholar
Figueirido, B., and Soibelzon, L. H. 2010. Inferring paleoecology in extinct tremartine bears using geometric morphometrics. Lethaia 43:209–222.Google Scholar
Figueirido, B., Palmqvist, P., and Pérez-Claros, J. A. 2009. Ecomorphological correlates of craniodental variation in bears revealed by geometric morphometrics: paleobiological implications for extinct taxa. Journal of Zoology 277:70–80.Google Scholar
Figueirido, B., Pérez-Claros, J. A., Torregrosa, V., Martín-Serra, A., and Palmqvist, P. 2010a. Demythologizing Arctodus simus, the ‘short-faced’ long-legged and predaceous bear that never was. Journal of Vertebrate Paleontology 30:262–275.CrossRefGoogle Scholar
Figueirido, B., Serrano-Alarcón, F. J., Slater, G., and Palmqvist, P. 2010b. Shape at the cross-roads: homoplasy and history in the evolution of the carnivoran skull towards herbivory. Journal of Evolutionary Biology 23:2579–2594.Google Scholar
Finarelli, J. A. 2008. A total evidence phylogeny of the Arctoidea (Carnivora: Mammalia): relationships among basal taxa. Journal of Mammalian Evolution 15:231–259.Google Scholar
Finarelli, J. A., and Flynn, J. 2006. Ancestral state reconstruction of body size in the Caniformia (Carnivora, Mammalia): the effects of incorporating data from the fossil record. Systematic Biology 55:301–313.Google Scholar
Finarelli, J. A., and Flynn, J. 2009. Brain-size evolution and sociality in Carnivora. Proceedings of the National Academy of Sciences USA 106:9345–9349.Google Scholar
Flynn, J. J., and Wesley-Hunt, G. D. 2005. Carnivora. Pp. 175–198 in Archibald, D. and Rose, K., eds. The rise of placental mammals: origins and relationships of the major extant clades. Johns Hopkins University Press, Baltimore.Google Scholar
Flynn, J. J., Finarelli, J. A., Zehr, S., Hsu, J., and Nedbal, M. A. 2005. Molecular phylogeny of the Carnivora (Mammalia): assessing the impact of increased sampling on resolving enigmatic relationships. Systematic Biology 54:317–337.Google Scholar
Ginsburg, L. 1966. Les amphicyons des phosphorites du Quercy. Annales de Paléontologie 52:23–64.Google Scholar
Ginsburg, L. 1977. Cynelos lemanensis (Pomel), carnivore ursidé de l'Aquitanien d'Europe. Annales de Paléontologie 42:97–117.Google Scholar
Gittleman, J. L., and Kot, M. 1990. Statistics and a null model for estimating phylogenetic effects. Systematic Zoology 39:227–241.CrossRefGoogle Scholar
Gittleman, J. L., and Luh, H.-K. 1992. On comparing comparative methods. Annual Review of Ecology and Systematics 23:383–404.CrossRefGoogle Scholar
Gittleman, J. L., and Luh, H.-K. 1994. Phylogeny, evolutionary models and comparative methods: a simulation study. Pp. 103–122 in Eggleton, P., and Vane-Wright, R. I., eds. Phylogenetics and ecology. Academic Press, London.Google Scholar
Gonyea, W. J. 1976. Behavioral implications of saber-toothed felid morphology. Paleobiology 2:232–342.CrossRefGoogle Scholar
Goswami, A. 2006. Morphological integration in the carnivoran skull. Evolution 60:169–183.Google Scholar
Goswami, A. 2007. Phylogeny, diet, and cranial integration in australodelphian marsupials. PlosOne 2:e995. doi:10.1371/journal.pone.0000995.CrossRefGoogle ScholarPubMed
Goswami, A., Milne, N., and Wroe, S. 2010. Biting through constraints: cranial morphology, disparity and convergence across living and fossil carnivorous mammals. Proceedings of the Royal Society of London B (in press), doi: 10.1098/rspb.2010.2031.Google Scholar
Gould, S. J. 1980. Is a new evolutionary theory emerging? Paleobiology 6:119–130.CrossRefGoogle Scholar
Gould, S. J. 1989. A developmental constraint in Cerion, with comments on the definition and interpretation of constraint in evolution. Evolution 43:516–539.Google Scholar
Gould, S. J. 2002. The structure of evolutionary theory. Harvard University Press, Cambridge.Google Scholar
Gould, S. J., and Lewontin, R. 1979. The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist program. Proceedings of the Royal Society of London B 205:581–598.Google Scholar
Greaves, W. S. 1982. A mechanical limitation on the position of the jaw muscles in mammals: the one third-rule. Journal of Mammalogy 63:261–266.Google Scholar
Harvey, P. H., and Pagel, M. D. 1991. The comparative method in evolutionary biology. Oxford University Press, Oxford.Google Scholar
Harvey, P. H., Brown, A. J. Leigh, Smith, J. M., and Nee, S. 1996. New uses for new phylogenies. Oxford University Press, Oxford.CrossRefGoogle Scholar
Herring, S. W., and Herring, S. E. 1974. The superficial masseter and gape in mammals. American Naturalist 108:561–576.Google Scholar
Holliday, J. A., and Steppan, S. J. 2004. Evolution of hypercarnivory: the effect of specialization on morphological and taxonomic diversity. Paleobiology 30:108–128.2.0.CO;2>CrossRefGoogle Scholar
Hunt, R. M. Jr. 1998. Amphicyonidae. Pp. 196–227 in Janis, C. M., Scott, K. M., and Jacobs, L. L., eds. Evolution of tertiary mammals of North America., Vol 1. Terrestrial carnivores, ungulates and ungulatelike mammals Cambridge University Press, Cambridge.Google Scholar
Janis, C. M., and Wilhem, P. 1993. Were there mammalian pursuit predators in the Tertiary? Dances with wolf avatars. Journal of Mammalian Evolution 1:103–125.CrossRefGoogle Scholar
Joeckel, R. M. 1998. Unique frontal sinuses in fossil and living Hyaenidae (Mammalia, Carnivora): description and interpretation. Journal of Vertebrate Paleontology 18:627–639.Google Scholar
Kruuk, H., and Turner, M. 1967. Comparative notes on predation by lion, leopard, cheetah and wild dog in the Serengeti area, east Africa. Mammalia 31:1–23.Google Scholar
Kurtén, B. 1964. The evolution of the polar bear, Ursus maritimus (Phipps). Acta Zoologica Fennica 108:1–26.Google Scholar
Lohmann, G. P. 1983. Eigenshape analysis of microfossils: a general morphometric method for describing changes in shape. Mathematical Geology 15:659–672.Google Scholar
MacLeod, N. 1999. Generalizing and extending eigenshape method of shape space visualization and analysis. Paleobiology 25:107–138.Google Scholar
MacLeod, N. 2001a. The role of phylogeny in quantitative paleobiological data analysis. Paleobiology 27:226–240.2.0.CO;2>CrossRefGoogle Scholar
MacLeod, N. 2001b. Landmarks, localization, and the use of morpho metrics in phylogenetic analysis. Pp. 97–233 in Adrian, J. M., Edgecombe, G. D., and Lieberman, B. S., eds. Fossils, phylogeny, and form. Kluwer Academic/Plenum, New York.Google Scholar
MacLeod, N. 2002a. Testing evolutionary hypotheses with adaptive landscapes: use of random morphological simulation studies. Mathematische Geologie 6:45–55.Google Scholar
MacLeod, N. 2002b. Phylogenetic signals in morphometric data. Pp. 100–138 in MacLeod, N. and Forey, P., eds. Morphometries, shape, and phylogenetics. Taylor and Francis, London.CrossRefGoogle Scholar
MacLeod, N. 2007. Groups I. Palaeontological Association Newsletter 64:35–45.Google Scholar
Manley, B. F. J. 1994. Multivariate statistical methods: a primer, 2d ed. Chapman and Hall/CRC, Boca Raton, Fla.Google Scholar
Martínez-Navarro, B., and Palmqvist, P. 1995. Presence of the African machairodont Megantereon whitei (BROOM 1937) (Felidae, Carnivora, Mammalia) in the lower Pleistocene site of Venta Micena (Orce, Granada, Spain), with some considerations on the origin, evolution and dispersal of the genus. Journal of Archaeological Science 22:569–582.Google Scholar
Martins, E. P. 2004. COMPARE, Version 4.6b. Computer programs for the statistical analysis of comparative data. Distributed by the author at http://compare.bio.indiana.edu/. Department of Biology, Indiana University, Bloomington.Google Scholar
Martins, E. P., and Hansen, T. F. 1997. Phylogenies and the comparative method: a general approach to incorporating phylogenetic information into the analysis of interspecific data. American Naturalist 149:646–667.Google Scholar
Matthew, W. D. 1910. The phylogeny of the Felidae. Bulletin of the American Museum of Natural History 28:289–316.Google Scholar
McGhee, G. R. 1980. Shell form in the biconvex Articulate Brachiopoda: a geometric analysis. Paleobiology 6:57–76.Google Scholar
McGhee, G. R. 1991. Theoretical morphology: the concept and its applications. In Gilinsky, N. L. and Signor, P. W., eds. Analytical paleobiology. Short Courses in Paleontology 4:87–102. Paleontological Society, Knoxville, Tenn.Google Scholar
McGhee, G. R. 1999. Theoretical morphology: the concept and its applications. Columbia University Press, New York.Google Scholar
Meloro, C., Raia, P., Piras, P., Barbera, C., and O'Higgins, P. 2008. The shape of the mandibular corpus in large fissiped carnivores: allometry, function and phylogeny. Zoological Journal of the Linnean Society 154:832–845.Google Scholar
Milne, N., and O'Higgins, P. 2002. Inter-specific variation in Macropus crania: form, function and phylogeny. Journal of Zoology 256:523–535.CrossRefGoogle Scholar
Nowack, R. 1991. Walker's Mammals of the world. Johns Hopkins University Press, Baltimore.Google Scholar
Okamoto, T. 1988. Analysis of heteromorph ammonoids by differential geometry. Paleontology 31:35–52.Google Scholar
Oster, G., and Alberch, P. 1982. Evolution and bifurcation of developmental programs. Evolution 3:444–459.CrossRefGoogle Scholar
Palmqvist, P., Arribas, A., and Martínez-Navarro, B. 1999. Ecomorphological study of large canids from the lower Pleistocene of southeastern Spain. Lethaia 32:75–88.Google Scholar
Palmqvist, P., Mendoza, M., Arribas, A., and Gröcke, D. 2002. Estimating the body mass of Pleistocene canids: discussion of some methodological problems and a new ‘taxon free’ approach. Lethaia 35:358–360.Google Scholar
Palmqvist, P., Torregrosa, V., Pérez-Claros, J. A., Martínez-Navarro, B., and Turner, A. 2007. A re-evaluation of the diversity of Megantereon (Mammalia, Carnivora, Machairodontinae) and the problem of species identification in extinct carnivores. Journal of Vertebrate Paleontology 27:160–175.Google Scholar
Polly, P. D., Wesley-Hunt, G. D., Heinrich, R. E., Davis, G., and Houde, P. 2006. Earliest known carnivoran auditory bulla and support for a recent origin of crown-group Carnivora (Eutheria, Mammalia). Paleontology 49:1019–1027.CrossRefGoogle Scholar
Purvis, A., Gittleman, J. L., and Luh, H.-K. 1994. Truth or consequences: effects of phylogenetic accuracy on two comparative methods. Journal of Theoretical Biology 167:293–300.Google Scholar
Radinsky, L. B. 1981a. Evolution of skull shape in carnivores I. Representative modern carnivores. Biological Journal of the Linnean Society 15:369–388.Google Scholar
Radinsky, L. B. 1981b. Evolution of skull shape in carnivores. II. Additional modern carnivores. Biological Journal of the Linnean Society 16:337–355.CrossRefGoogle Scholar
Radinsky, L. B. 1982. Evolution of skull shape in carnivores. III. The origin and early radiation of the modern carnivore families. Paleobiology 8:177–195 Google Scholar
Raup, D. M. 1966. Geometric analysis of shell coiling: general problems. Journal of Paleontology 40:1178–1190.Google Scholar
Raup, D. M. 1967. Geometric analysis of shell coiling: coiling in ammonoids. Journal of Paleontology 41:43–65.Google Scholar
Raup, D. M., and Michelson, A. 1965. Theoretical morphology of the coiled shell. Science 147:1294–1295.CrossRefGoogle ScholarPubMed
Ray, T. S. 1990. Application of “eigenshape” analysis to second order leaf shape ontogeny in Syngonium podophyllum (Araceae). Pp. 201–213 in Rohlf, F. J. and Bookstein, F. L., eds. Proceedings of the Michigan Morphometrics Workshop. University of Michigan Museum of Zoology, Ann Arbor.Google Scholar
Ray, T. S. 1992. Landmark eigenshape analysis: homologous contours: leaf shape in Syngonium (Araceae). American Journal of Botany 79:69–76.Google Scholar
Rohlf, F. J. 1992. The analysis of shape variation using ordinations of fitted functions. Pp. 95–112 in Sorensen, J. T. and Foottit, R., eds. Ordinations in the study of morphology, evolution and systematics of insects: applications and quantitative genetic rationals. Elsevier, Amsterdam.Google Scholar
Rohlf, F. J. 1993. Relative warp analysis and an example of its application to mosquito wings. Pp. 131–159 in Marcus, L. F., Bello, E., and Garcia-Valdecasas, A., eds. Contributions to morphometrics. Museo Nacional de Ciencias Naturales, Madrid.Google Scholar
Rohlf, F. J. 2001. Comparative methods for the analysis of continuous variables: geometric interpretations. Evolution 55:2143–2160.Google ScholarPubMed
Rohlf, F. J. 2006. A comment on phylogenetic correction. Evolution 60:1509–1515.Google Scholar
Rohlf, F. J., and Slice, D. S. 1990. Extensions of the Procrustes method for the optimal superimposition of landmarks. Systematic Zoology 39:40–59.CrossRefGoogle Scholar
Sacco, T., and Van Valkenburgh, B. 2004. Ecomorphological indicators of feeding behavior in bears (Carnivora: Ursidae). Journal of Zoology 263:41–54.Google Scholar
Salesa, M. J., Antón, M., Turner, A., and Morales, J. 2005. Aspects of the functional morphology in the cranial and cervical skeleton of the sabretoothed cat Paramachairodus ogygia (Kaup, 1832) (Felidae, Machairodontinae) from the Late Miocene of Spain: implications for the origins of the machairodont killing bite. Zoological Journal of the Linnean Society 144:363–377.Google Scholar
Salesa, M. J., Antón, M., Turner, A., and Morales, J. 2006. Inferred behavior and ecology of the primitive saber-toothed cat Paramachairodus ogygia (Felidae, Machairodontinae) from the Late Miocene of Spain. Journal of Zoology 268:243–254.CrossRefGoogle Scholar
Sears, K. E., Goswami, A., Flynn, J. J., and Niswander, L. A. 2007. The correlated evolution of Runx2 tandem repeats, transcriptional activity, and facial length in Carnivora. Evolution and Development 9:555–565.Google Scholar
Seilacher, A. 1970. Arbeitskonzept zur Konstruktion-Morphologie. Lethaia 3:393–396.Google Scholar
Slater, G. J., and Van Valkenburgh, B. 2008. Long in the tooth: evolution of sabertooth cat cranial shape. Paleobiology 34:403–419.Google Scholar
Slater, G. J., and Van Valkenburgh, B. 2009. Allometry and performance: the evolution of skull form and function in felids. Journal of Evolutionary Biology 22:2278–2287.Google Scholar
Slater, G. J., Dummont, E., and Van Valkenburgh, B. 2009. Implications of predatory specialization for cranial form and function in canids. Journal of Zoology 278:181–188.Google Scholar
Slater, G. J., Figueirido, B., Louis, L., Yang, P., and Van Valkenburgh, B. 2010. Biomechanical Consequences of Rapid Evolution in the Polar Bear Lineage. PLoS ONE 5(11):e13870. doi:10.1371/journal.pone.0013870.Google Scholar
Sorkin, B. 2006. Ecomorphology of the giant short faced bears Agriotherium and Arctodus . Historical Biology 18:1–20.Google Scholar
Stefen, C., and Rensberger, J. M. 1999. The specialized structure of hyaenid enamel: description and development within the lineage—including percrocutids. Scanning Microscopy 13:363–380.Google Scholar
Tanner, J. B., Dumont, E. R., Sakai, S. T., Lundrigan, B. L., and Holekamp, K. E. 2008. Of arcs and vaults: the biomechanics of bone-cracking in spotted hyenas (Crocuta crocuta). Biological Journal of the Linnean Society 95:246–255.Google Scholar
Therrien, F. 2005a. Mandibular force profiles of extant carnivorans and implications for the feeding behavior of extinct predators. Journal of Zoology 267:249–270.Google Scholar
Therrien, F. 2005b. Feeding behavior and bite force of sabretoothed predators. Zoological Journal of the Linnean Society 145:393–426.Google Scholar
Tseng, J. 2009. Cranial function in a late Miocene Dinocrocuta gigantea (Mammalia: Carnivora) revealed by comparative finite element analysis. Biological Journal of the Linnean Society 96:51–67.CrossRefGoogle Scholar
Turnbull, W. D. 1970. Mammalian masticatory apparatus. Fieldiana (Geology) 18:149–356.Google Scholar
Van Valkenburgh, B. 1988. Trophic diversity in past and present guilds of large predatory mammals. Paleobiology 14:155–173.Google Scholar
Van Valkenburgh, B. 1989. Carnivore dental adaptations and diet: a study of trophic diversity within guilds. Pp 410–436 in Gittleman, J. L., ed. Carnivore behavior, ecology, and evolution, Vol. 1. Cornell University Press, Ithaca, N.Y. CrossRefGoogle Scholar
Van Valkenburgh, B. 1991. Iterative evolution of hypercarnivory in canids (Mammalia: Carnivora): evolutionary interactions among sympatic predators. Paleobiology 17:340–362.Google Scholar
Van Valkenburgh, B. 1995. Tracking ecology over geological time: evolution within guilds of vertebrates. Trends in Ecology and Evolution 10:71–76.Google Scholar
Van Valkenburgh, B. 1999. Major patterns in the history of carnivorous mammals. Annual Reviews of Earth and Planetary Sciences 27:463–93.Google Scholar
Van Valkenburgh, B. 2007. Déjà vu: the evolution of feeding morphologies in the Carnivora. Integrative and Comparative Biology 47:147–163.Google Scholar
Van Valkenburgh, B., and Koepfli, K.-P. 1993. Cranial and dental adaptations to predation in canids. Symposium of the Zoological Society of London 65:15–37.Google Scholar
Van Valkenburgh, B., Sacco, T., and Wang, X. 2003. Pack hunting in Miocene borophagine dogs: evidence from craniodental morphology and body size. Bulletin of the American Museum of Natural History 279:147–162.Google Scholar
Viret, J. 1951. Catalog critique de la faune des mammifères miocènes de la Grive-Saint-Alban (Idre). I. Chiroptères, Carnivores, Edentates, Pholidotes. Nouvelles Archives du Museum d'Histoire Naturelle (Lyon) 3:1–104.Google Scholar
Wayne, R. K. 1986. Cranial morphology of domestic and wild canids: the influence of development in the morphological change. Evolution 40:243–261.Google Scholar
Werdelin, L. 1987a. Jaw geometry and molar morphology in marsupial carnivores: analysis of constraint and its macroevolutionary consequences. Paleobiology 13:342–350.Google Scholar
Werdelin, L. 1987b. Supernumerary teeth in Lynx lynx and the irreversibility of evolution. Journal of Zoology 211:259–266.Google Scholar
Werdelin, L. 1989. Constraint and adaptation in the bone-cracking canid Osteoborus (Mammalia: Canidae). Paleobiology 15:387–401.CrossRefGoogle Scholar
Wesley-Hunt, G.D., and Flynn, J.J. 2005. Phylogeny of the Carnivora: basal relationships among the carnivoramorphans, and assessment of the position of “Miacoidea” relative to crown-clade Carnivora. Journal of Systematic Paleontology 3:1–28.Google Scholar
Wesley-Hunt, G. D., and Werdelin, L. 2005. Basicranial morphology and phylogenetic position of the upper Eocene carnivoramorphan Quercygale . Acta Palaeontologica Polonica 50:837–846.Google Scholar
Westoby, M., Leishman, M., and Lord, J. 1995a. Further remarks on phylogenetic correction. Journal of Ecology 83:727–729.Google Scholar
Westoby, M., Leishman, M., and Lord, J. 1995b. Issues of interpretation after relating comparative data sets to phylogeny. Journal of Ecology 83:892–893.Google Scholar
Wroe, S., and Milne, N. 2007. Convergence and remarkably consistent constraint in the evolution of carnivore skull shape. Evolution 61:1251–1260.Google Scholar
Wyss, A. R., and Flynn, J. J. 1993. A phylogenetic analysis and definition of the Carnivora. Pp. 32–52 in Szalay, F. S., Novacek, M. J., and McKenna, M. C., eds. Mammal phylogeny. Springer, New York.Google Scholar
Zahn, C. T., and Roskies, R. Z. 1972. Fourier descriptors for plane closed curves. IEEE Transactions on Computers C–21:269–281.Google Scholar