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Evolutionary Biology

, Volume 35, Issue 4, pp 231–247 | Cite as

Focal Review: The Origin(s) of Modern Amphibians

  • Jason S. Anderson
Focal Reviews

Abstract

The recent description of the stem batrachian Gerobatrachus has changed the terms of the ongoing debate on the origin of extant amphibians (Lissamphibia: frogs, salamanders, and the limbless caecilians). This important fossil, through a shared mosaic of unique derived salientian and urodele characters, links frogs and salamanders with an archaic group of fossil amphibians known as amphibamid temnospondyls. The present paper reviews the impact of this fossil on morphological and molecular phylogenies, and divergence timing estimates based on molecular models and the fossil record. In morphology, most recent efforts have focused on better characterizing the anatomy and relationships of amphibamid temnospondyls. Progress has also been made with the complete description of the earliest caecilian Eocaecilia; however, the question of caecilian origins remains unresolved at present. The large scale phylogenetic analyses all agree on the overall tetrapod tree phylogenetic structure, and the largest analyses agree that the origin of at least frogs and salamanders among fossils from family Amphibamidae. Conversely, all molecular based analyses find a monophyletic Lissamphibia, and a Batrachia terminal dichotomy, which raises questions over either the validity of morphological analyses that support lissamphibian polyphyly or about the possibility of long branch attraction given the short internal divergences and long subsequent branches. Paradoxically, the estimated date of the lissamphibian divergence best matches the fossil record if timed to the split between lepospondyls and temnospondyls. Future research should focus on development and fine details of cranial anatomy of fossil and extant amphibians to produce new evidence and clarity into the question of lissamphibian, and especially caecilian, origins.

Keywords

Lissamphibia Temnospondyli Lepospondyli Molecular clock Divergence estimate Origins hypothesis Gerobatrachus Phylogenetic analysis Development 

Notes

Acknowledgments

I thank Benedikt Hallgrimsson for inviting this review, and for his patience during its completion. Reviews by Marcello Ruta and David Wake helped improve the manuscript. I thank Trond Sigurdsen and Nadia Fröbisch for sending me advanced copies of their respective works currently in press. My thoughts on this subject have been challenged and improved through discussions with: David Berman, John Bolt, Robert Carroll, Jenny Clack, Nadia Fröbisch, Susan Evans, Michel Laurin, Mike Lee, David Marjanović, Andrew Milner, Robert Reisz, and Marcello Ruta. This study was supported by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada.

References

  1. Anderson, J. S. (2001). The phylogenetic trunk: Maximal inclusion of taxa with missing data in an analysis of the Lepospondyli. Systematic Biology, 50(2), 170–193. doi: 10.1080/10635150119889.PubMedCrossRefGoogle Scholar
  2. Anderson, J. S. (2002a). Revision of the aïstopod genus Phlegethontia (Tetrapoda: Lepospondyli). Journal of Paleontology, 76, 1029–1046. doi:10.1666/0022-3360(2002)076<1029:ROTAGP>2.0.CO;2.CrossRefGoogle Scholar
  3. Anderson, J. S. (2002b). Use of well-known names in phylogenetic nomenclature: A reply to Laurin. Systematic Biology, 51(5), 822–827. doi: 10.1080/10635150290102447.PubMedCrossRefGoogle Scholar
  4. Anderson, J. S. (2007). Incorporating ontogeny into the matrix: A phylogenetic evaluation of developmental evidence for the origins of modern amphibians. In J. S. Anderson & H.-D. Sues (Eds.), Major transitions in vertebrate evolution (pp. 182–227). Bloomington: Indiana University Press.Google Scholar
  5. Anderson, J. S., Carroll, R. L., & Rowe, T. B. (2003). New information on Lethiscus stocki (Tetrapoda: Lepospondyli: Aistopoda) from high-resolution computed tomography and a phylogenetic analysis of Aistopoda. Canadian Journal of Earth Sciences, 40, 1071–1083. doi: 10.1139/e03-023.CrossRefGoogle Scholar
  6. Anderson, J. S., Henrici, A. C., Sumida, S. S., Martens, T., & Berman, D. S. (2008a). Georgenthalia clavinasica, a new genus and species of dissorophoid temnospondyl from the Early Permian of Germany, and the relationships of the Family Amphibamidae. Journal of Vertebrate Paleontology, 28(1), 61–75. doi: 10.1671/0272-4634(2008)28[61:GCANGA]2.0.CO;2.CrossRefGoogle Scholar
  7. Anderson, J. S., & Reisz, R. R. (2003). A new microsaur (Tetrapoda: Lepospondyli) from the Lower Permian of Richards Spur (Fort Sill) Oklahoma. Canadian Journal of Earth Sciences, 40, 499–505. doi: 10.1139/e02-066.CrossRefGoogle Scholar
  8. Anderson, J. S., Reisz, R. R., Scott, D., Fröbisch, N. B., & Sumida, S. S. (2008b). A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. Nature, 453, 515–518. doi: 10.1038/nature06865.PubMedCrossRefGoogle Scholar
  9. Benton, M. J. (1994). Palaeontological data and identifying mass extinctions. Trends in Ecology & Evolution, 9(5), 181. doi: 10.1016/0169-5347(94)90083-3.CrossRefGoogle Scholar
  10. Benton, M. J. (2003). The quality of the fossil record. In P. C. J. Donoghue & M. P. Smith (Eds.), Telling the evolutionary time: Molecular clocks and the fossil record (pp. 66–90). London: Taylor and Francis.Google Scholar
  11. Benton, M. J., & Ayala, F. J. (2003). Dating the tree of life. Science, 300, 1698–1700. doi: 10.1126/science.1077795.PubMedCrossRefGoogle Scholar
  12. Benton, M. J., & Donoghue, P. C. J. (2007). Paleontological evidence to date the tree of life. Molecular Biology and Evolution, 24(1), 26–53. doi: 10.1093/molbev/msl150.PubMedCrossRefGoogle Scholar
  13. Bergsten, J. (2005). A review of long-branch attraction. Cladistics, 21(2), 163–193. doi: 10.1111/j.1096-0031.2005.00059.x.CrossRefGoogle Scholar
  14. Bolt, J. R. (1969). Lissamphibian origins: Possible protolissamphibian from the Lower Permian of Oklahoma. Science, 166, 888–891. doi: 10.1126/science.166.3907.888.PubMedCrossRefGoogle Scholar
  15. Bolt, J. R. (1977). Dissorophoid relationships and ontogeny, and the origin of the Lissamphibia. Journal of Paleontology, 51(2), 235–249.Google Scholar
  16. Bolt, J. R. (1979). Amphibamus grandiceps as a juvenile dissorophid: Evidence and implications. In M. H. Nitecki (Ed.), Mazon creek fossils (pp. 529–563). New York: Academic Press.Google Scholar
  17. Bolt, J. R. (1980). New tetrapods with bicuspid teeth from the Fort Sill locality (Lower Permian, Oklahoma). Neues Jahrbuch für Geologie und Paläontologie. Monatshefte, 8, 449–459.Google Scholar
  18. Bolt, J. R. (1991). Lissamphibian origins. In H.-P. Schultze & L. Trueb (Eds.), Origins of the higher groups of tetrapods: Controversy and consensus (pp. 194–222). Ithaca and London: Comstock Publishing Associates.Google Scholar
  19. Boy, J. A., & Sues, H.-D. (2000). Branchiosaurs: Larvae, metamorphosis and heterochrony in temnospondyls and seymouriamorphs. In H. Heatwole & R. L. Carroll (Eds.), Amphibian biology. Volume 4: Paleontology: The evolutionary history of amphibians (pp. 1150–1197). Chipping Norton: Surrey Beatty & Sons.Google Scholar
  20. Carroll, R. L. (2000). Eocaecilia and the origin of caecilians. In H. Heatwole & R. L. Carroll (Eds.), Amphibian biology. Vol. 4: Palaeontology: The evolutionary history of amphibians (pp. 1402–1411). Chipping Norton: Surrey Beatty and Sons.Google Scholar
  21. Carroll, R. L. (2004). The importance of branchiosaurs in determining the ancestry of the modern amphibian orders. Neues Jahrbuch für Geologie und Palaontologie. Abhandlungen, 232, 157–180.Google Scholar
  22. Carroll, R. L. (2007). The Palaeozoic ancestry of salamanders, frogs and caecilians. Zoological Journal of the Linnean Society, 150(s1), 1–140. doi: 10.1111/j.1096-3642.2007.00246.x.CrossRefGoogle Scholar
  23. Carroll, R. L., & Currie, P. J. (1975). Microsaurs as possible apodan ancestors. Zoological Journal of the Linnean Society, 57(3), 229–247. doi: 10.1111/j.1096-3642.1975.tb00817.x.CrossRefGoogle Scholar
  24. Carroll, R. L., & Gaskill, P. (1978). The order Microsauria. Memoirs of the American Philosophical Society, 126, 1–211.Google Scholar
  25. Carroll, R. L., & Holmes, R. (1980). The skull and jaw musculature as guides to the ancestry of salamanders. Zoological Journal of the Linnean Society, 68(1), 1–40. doi: 10.1111/j.1096-3642.1980.tb01916.x.CrossRefGoogle Scholar
  26. Clack, J. A., & Milner, A. R. (1993). Platyrhinops from the upper carboniferous of Linton and Nýřany, and the family Peliontidae (Amphibia; Temnospondyli). In D. Schweiss & U. Heidtke (Eds), New results on permo-carboniferous fauna (pp. 185–192). Bad Dürkheim.Google Scholar
  27. Coates, M. I., & Ruta, M. (2000). Early tetrapod evolution. Trends in Ecology & Evolution, 15(8), 327–328. doi: 10.1016/S0169-5347(00)01927-3.CrossRefGoogle Scholar
  28. Davit-Beal, T., Chisaka, H., Delgado, S., & Sire, J.-Y. (2007). Amphibian teeth: Current knowledge, unanswered questions, and some directions for future research. Biological Reviews of the Cambridge Philosophical Society, 82(1), 49–81. doi: 10.1111/j.1469-185X.2006.00003.x.PubMedCrossRefGoogle Scholar
  29. de Queiroz, K. (1992). Phylogenetic definitions and taxonomic philosophy. Biology and Philosophy, 7, 295–313. doi: 10.1007/BF00129972.CrossRefGoogle Scholar
  30. de Queiroz, K., & Gauthier, J. (1990). Phylogeny as a central principle in taxonomy: Phylogenetic definitions of taxon names. Systematic Zoology, 39(4), 307–322. doi: 10.2307/2992353.CrossRefGoogle Scholar
  31. de Queiroz, K., & Gauthier, J. (1992). Phylogenetic taxonomy. Annual Review of Ecology and Systematics, 23, 449–480.CrossRefGoogle Scholar
  32. Duellman, W. E., & Trueb, L. (1994). Biology of amphibians (2nd ed., pp. 1–670). Baltimore: The Johns Hopkins University Press.Google Scholar
  33. Felsenstein, J. (1978). Cases in which parsimony or compatability methods will be positively misleading. Systematic Zoology, 27(4), 401–410. doi: 10.2307/2412923.CrossRefGoogle Scholar
  34. Fröbisch, N. B., Carroll, R. L., & Schoch, R. R. (2007). Limb ossification in the Paleozoic branchiosaurid Apateon (Temnospondyli) and the early evolution of preaxial dominance in tetrapod limb development. Evolution & Development, 9, 69–75.Google Scholar
  35. Fröbisch, N. B., & Reisz, R. R. (2008). A new Lower Permian amphibamid (Dissorophoidea, Temnospondyli) from the fissure fill deposits near Richards Spur, Oklahoma. Journal of Vertebrate Paleontology, 28 (in press). doi: 10.1671/0272-4634(2008)28[770:ANSOES]2.0.CO;2.
  36. Frost, D. R., Grant, T., Faivovich, J., Bain, R. H., Haas, A., Haddad, C. F. B., et al. (2006). The amphibian tree of life. Bulletin of the American Museum of Natural History, 297, 1–370. doi: 10.1206/0003-0090(2006)297[0001:TATOL]2.0.CO;2.CrossRefGoogle Scholar
  37. Haas, A., & Kleinteich, T. (2007). Homologies of larval amphibians and the evolution of the anuran tadpole. Journal of Morphology, 268(12), 1079.Google Scholar
  38. Havelková, P., & Roček, Z. (2006). Transformation of the pectoral girdle in the evolutionary origin of frogs: insights from the primitive anuran Discoglossus. Journal of Anatomy, 209(1), 1–11. doi: 10.1111/j.1469-7580.2006.00583.x.PubMedCrossRefGoogle Scholar
  39. Huelsenbeck, J. P. (1994). Comparing the stratigraphic record to estimates of phylogeny. Paleobiology, 20(4), 470.Google Scholar
  40. Huelsenbeck, J. P., & Hillis, D. M. (1993). Success of phylogenetic methods in the four-taxon case. Systematic Biology, 42(3), 247–264. doi: 10.2307/2992463.CrossRefGoogle Scholar
  41. Hugall, A. F., Foster, R., & Lee, M. S. Y. (2007). Calibration choice, rate smoothing, and the pattern of tetrapod diversification according to the long nuclear gene RAG-1. Systematic Biology, 56(4), 543–563. doi: 10.1080/10635150701477825.PubMedCrossRefGoogle Scholar
  42. Huttenlocker, A. K., Pardo, J. D., & Small, B. J. (2007). Plemmyradytes shintoni, gen. et sp. nov., an Early Permian amphibamid (Temnospondyli: Dissorophoidea) from the Eskridge formation, Nebraska. Journal of Vertebrate Paleontology, 27(2), 316–328. doi: 10.1671/0272-4634(2007)27[316:PSGESN]2.0.CO;2.CrossRefGoogle Scholar
  43. Igawa, T., Kurabayashi, A., Usuki, C., Fujii, T., & Sumida, M. (2008). Complete mitochondrial genomes of three neobatrachian anurans: A case study of divergence time estimation using different data and calibration settings. Gene, 407(1–2), 116–129. doi: 10.1016/j.gene.2007.10.001.PubMedCrossRefGoogle Scholar
  44. Jenkins, F. A., Walsh, D. M., & Carroll, R. L. (2007). Anatomy of Eocaecilia micropodia, a limbed caecilian of the Early Jurassic. Bulletin of the Museum of Comparative Zoology, 158(6), 285–365. doi: 10.3099/0027-4100(2007)158[285:AOEMAL]2.0.CO;2.CrossRefGoogle Scholar
  45. Kim, J. (1996). General inconsistency conditions for maximum parsimony: Effects of branch lengths and increasing numbers of taxa. Systematic Biology, 45(3), 363–374. doi: 10.2307/2413570.CrossRefGoogle Scholar
  46. Laurin, M. (1998). The importance of global parsimony and historical bias in understanding tetrapod evolution. Part I. Systematics, middle ear evolution and jaw suspension. Annales des Science Naturelles, Paris, 1, 1–42.Google Scholar
  47. Laurin, M. (2002). Tetrapod phylogeny, amphibian origins, and the definition of the name Tetrapoda. Systematic Biology, 51, 364–369. doi: 10.1080/10635150252899815.PubMedCrossRefGoogle Scholar
  48. Laurin, M., & Anderson, J. S. (2004). Meaning of the name Tetrapoda in the scientific literature: An exchange. Systematic Biology, 53(1), 68–80. doi: 10.1080/10635150490264716.PubMedCrossRefGoogle Scholar
  49. Laurin, M., Girondot, M., & de Ricqlès, A. (2000a). Early tetrapod evolution. Trends in Ecology & Evolution, 15(3), 118–123. doi: 10.1016/S0169-5347(99)01780-2.CrossRefGoogle Scholar
  50. Laurin, M., Girondot, M., & de Ricqlès, A. (2000b). Reply. Trends in Ecology & Evolution, 15(8), 328. doi: 10.1016/S0169-5347(00)01928-5.CrossRefGoogle Scholar
  51. Laurin, M., & Reisz, R. R. (1997). A new perspective on tetrapod phylogeny. In S. S. Sumida & K. L. M. Martin (Eds.), Amniote origins (pp. 9–59). San Diego: Academic Press.CrossRefGoogle Scholar
  52. Laurin, M., & Reisz, R. R. (1999). A new study of Solenodonsaurus janenschi, and a reconsideration of amniote origins and stegocephalian evolution. Canadian Journal of Earth Sciences, 36(8), 1239–1255. doi: 10.1139/cjes-36-8-1239.CrossRefGoogle Scholar
  53. Lebedkina, N. S. (2004). Evolution of the amphibian skull. In S. V. Smirnov (translator) & S. L. Kuzmin (Ed.). Sofia, Bulgaria: Pensoft Publishers, 265 pp.Google Scholar
  54. Lee, M. S. Y., & Anderson, J. S. (2006). Molecular clocks and the origin(s) of modern amphibians. Molecular Phylogenetics and Evolution, 40, 635–639. doi: 10.1016/j.ympev.2006.03.013.PubMedCrossRefGoogle Scholar
  55. Maddin, H. C., & Anderson, J. S. (2008). Neurocranial anatomy of a microsaurian lepospondyl, Carrolla craddocki, extracted via high-resolution computed tomography. Journal of Vertebrate Paleontology, 28(Supplement to 3), 110A.Google Scholar
  56. Maddin, H. C., Anderson, J. S., & Reisz, R. R. (2007). Braincase ontogeny of a new large trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma. Journal of Vertebrate Paleontology, 27(Supplement to 3), 110A.Google Scholar
  57. Marcus, H., Stimmelmayr, E., & Porsch, G. (1935). Die Ossifikation des Hypogeophisschädels. Beitrag zur Kenntnis der Gymnophionen XXV. Gegenbaurs Morphologisches Jahrbuch, 76, 375–420.Google Scholar
  58. Marjanović, D., & Laurin, M. (2007). Fossils, molecules, divergence times, and the origin of lissamphibians. Systematic Biology, 56(3), 369–388. doi: 10.1080/10635150701397635.PubMedCrossRefGoogle Scholar
  59. Müller, H. (2006). Ontogeny of the skull, lower jaw, and hyobranchial skeleton of Hypogeophis rostratus (Amphibia: Gymnophiona: Caeciliidae) revisited. Journal of Morphology, 267(8), 968–986. doi: 10.1002/jmor.10454.PubMedCrossRefGoogle Scholar
  60. Müller, H., Oommen, O., & Bartsch, P. (2005). Skeletal development of the direct-developing caecilian Gegeneophis ramaswamii (Amphibia: Gymnophiona: Caeciliidae). Zoomorphology, 124(4), 171–188. doi: 10.1007/s00435-005-0005-6.CrossRefGoogle Scholar
  61. Nussbaum, R. A. (1983). The evolution of a unique dual jaw closing mechanism in caecilians (Amphibia: Gymnophiona). Journal of Zoology, 199, 545–554.CrossRefGoogle Scholar
  62. Panchen, A. L., & Smithson, T. R. (1988). The relationships of the earliest tetrapods. In M. J. Benton (Ed.), The phylogeny and classification of the tetrapods Vol. 1: Amphibians, reptiles, birds (pp. 1–32). Oxford: Clarendon Press.Google Scholar
  63. Parsons, T., & Williams, E. (1963). The relationship of modern Amphibia: A re-examination. The Quarterly Review of Biology, 38, 26–53. doi: 10.1086/403748.CrossRefGoogle Scholar
  64. Poe, S., & Swofford, D. L. (1999). Taxon sampling revisited. Nature, 398, 299–300. doi: 10.1038/18592.PubMedCrossRefGoogle Scholar
  65. Robinson, J., Ahlberg, P. E., & Koentges, G. (2005). The braincase and middle ear region of Dendrerpeton acadianum (Tetrapoda: Temnospondyli). Zoological Journal of the Linnean Society, 143, 577–597. doi: 10.1111/j.1096-3642.2005.00156.x.CrossRefGoogle Scholar
  66. Roček, Z., & Van Dijk, E. (2006). Patterns of larval development in Cretaceous pipid frogs. Acta Palaeontologica Polonica, 51(1), 111–126.Google Scholar
  67. Rocková, H., & Roček, Z. (2005). Development of the pelvis and posterior part of the vertebral column in the Anura. Journal of Anatomy, 206, 17–35. doi: 10.1111/j.0021-8782.2005.00366.x.PubMedCrossRefGoogle Scholar
  68. Roelants, K., Gower, D. J., Wilkinson, M., Loader, S. P., Biju, S. D., Guillaume, K., et al. (2007). Global patterns of diversification in the history of modern amphibians. Proceedings of the National Academy of Sciences of the United States of America, 104(3), 887–892. doi: 10.1073/pnas.0608378104.PubMedCrossRefGoogle Scholar
  69. Romer, A. S. (1945). Vertebrate paleontology (p. 687). Chicago: University of Chicago Press.Google Scholar
  70. Ruta, M., & Coates, M. I. (2007). Dates, nodes and character conflict: Addressing the lissamphibian origin problem. Journal of Systematic Palaeontology, 5, 69–122. doi: 10.1017/S1477201906002008.CrossRefGoogle Scholar
  71. Ruta, M., Coates, M. I., & Quicke, D. L. (2003). Early tetrapod relationships revisited. Biological Reviews of the Cambridge Philosophical Society, 78, 251–345. doi: 10.1017/S1464793102006103.PubMedCrossRefGoogle Scholar
  72. San Mauro, D., Gower, D. J., Oommen, O. V., Wilkinson, M., & Zardoya, R. (2004). Phylogeny of caecilian amphibians (Gymnophiona) based on complete mitochondrial genomes and nuclear RAG1. Molecular Phylogenetics and Evolution, 33, 413–427. doi: 10.1016/j.ympev.2004.05.014.PubMedCrossRefGoogle Scholar
  73. San Mauro, D., Vences, M., Alcobendas, M., Zardoya, R., & Meyer, A. (2005). Initial diversification of living amphibians predated the breakup of Pangaea. American Naturalist, 165(5), 590–599. doi: 10.1086/429523.PubMedCrossRefGoogle Scholar
  74. Schoch, R. R. (1992). Comparative ontogeny of Early Permian branchiosaurid amphibians. Developmental stages. Palaeontographica. Abteilung A, 222, 43–83.Google Scholar
  75. Schoch, R. R. (2002). The early formation of the skull in extant and Paleozoic amphibians. Paleobiology, 28(2), 278–296. doi:10.1666/0094-8373(2002)028<0278:TEFOTS>2.0.CO;2.CrossRefGoogle Scholar
  76. Schoch, R. R. (2003). Early larval ontogeny of the Permo-Carboniferous temnospondyl Sclerocephalus. Palaeontology, 46(5), 1055–1072. doi: 10.1111/1475-4983.00333.CrossRefGoogle Scholar
  77. Schoch, R. R. (2004). Skeleton formation in the Branchiosauridae: A case study in comparing ontogenetic trajectories. Journal of Vertebrate Paleontology, 24(2), 309–319. doi: 10.1671/1950.CrossRefGoogle Scholar
  78. Schoch, R. R. (2006). Skull ontogeny: Developmental patterns of fishes conserved across major tetrapod clades. Evolution & Development, 8(6), 524–536. doi: 10.1111/j.1525-142X.2006.00125.x.CrossRefGoogle Scholar
  79. Schoch, R. R., & Carroll, R. L. (2003). Ontogenetic evidence for the Paleozoic ancestry of salamanders. Evolution & Development, 5(3), 314–324. doi: 10.1046/j.1525-142X.2003.03038.x.CrossRefGoogle Scholar
  80. Schoch, R. R., & Fröbisch, N. B. (2006). Metamorphosis and neoteny: Alternative pathways in an extinct amphibian clade. Evolution; International Journal of Organic Evolution, 60(7), 1467–1475.PubMedGoogle Scholar
  81. Schoch, R. R., & Milner, A. R. (2004). Structure and implications of theories on the origin of lissamphibians. In G. Arratia, M. V. H. Wilson, & R. Cloutier (Eds.), Recent advances in the origin and early radiation of vertebrates (pp. 345–377). München: Verlag Dr. Fredrich Pfeil.Google Scholar
  82. Schoch, R. R., & Rubidge, B. S. (2005). The amphibamid Micropholis from the Lystrosaurus Assemblage Zone of South Africa. Journal of Vertebrate Paleontology, 25(3), 502–522. doi: 10.1671/0272-4634(2005)025[0502:TAMFTL]2.0.CO;2.CrossRefGoogle Scholar
  83. Shearman, R. (2008). Chondrogenesis and ossification of the lissamphibian pectoral girdle. Journal of Morphology, 269(4), 479–495. doi: 10.1002/jmor.10597.PubMedCrossRefGoogle Scholar
  84. Shubin, N. H., & Wake, D. B. (2003). Morphological variation, development, and evolution of the limb skeleton of Salamanders. In H. Heatwole & M. Davies (Eds.), Amphibian biology, Volume 5: Osteology (pp. 1782–1808). Chipping Norton, NSW, Australia: Surrey Beatty & Sons.Google Scholar
  85. Sigurdsen, T. (2008). The otic region of Doleserpeton (Temnospondyli) and its implications for the evolutionary origin of frogs. Zoological Journal of the Linnean Society, 154, 738–751.CrossRefGoogle Scholar
  86. Trueb, L., & Cloutier, R. (1991). A phylogenetic investigation of the inter- and intrarelationships of the Lissamphibia (Amphibia: Temnospondyli). In H.-P. Schultze & L. Trueb (Eds.), Origins of the higher groups of tetrapods: Controversy and consensus (pp. 174–193). Ithaca and London: Comstock Publishing Associates.Google Scholar
  87. Vallin, G., & Laurin, M. (2004). Cranial morphology and affinities of Microbrachis, and a reappraisal of the phylogeny and lifestyle of the first amphibians. Journal of Vertebrate Paleontology, 24(1), 56–72. doi: 10.1671/5.1.CrossRefGoogle Scholar
  88. Vieites, D. R., Min, M.-S., & Wake, D. B. (2007). Rapid diversification and dispersal during periods of global warming by plethodontid salamanders. Proceedings of the National Academy of Sciences of the United States of America, 104(50), 19903–19907. doi: 10.1073/pnas.0705056104.PubMedCrossRefGoogle Scholar
  89. Wake, M. H. (2003). The osteology of caecilians. In H. Heatwole & M. Davies (Eds.), Amphibian biology Volume 5: Osteology (pp. 1809–1876). Chipping Norton, NSW: Surrey Beatty & Sons.Google Scholar
  90. Wake, M. H., & Hanken, J. (1982). Development of the skull of Dermophis mexicanus (Amphibia: Gymnophiona), with comments on skull kinesis and amphibian relationships. Journal of Morphology, 173(2), 203–223. doi: 10.1002/jmor.1051730208.CrossRefGoogle Scholar
  91. Wellstead, C. F. (1991). Taxonomic revision of the Lysorophia, Permo-Carboniferous lepospondyl amphibians. Bulletin of the American Museum of Natural History, 209, 1–90.Google Scholar
  92. Wellstead, C. F. (1998). Order Lysorophia. In P. Wellnhofer (Ed.), Lepospondyli (pp. 133–148). München: Verlag Dr. Friedrich Pfeil.Google Scholar
  93. Wills, M. A. (1999). Congruence between phylogeny and stratigraphy: Randomization tests and the gap excess ratio. Systematic Biology, 48(3), 559–580. doi: 10.1080/106351599260148.CrossRefGoogle Scholar
  94. Zardoya, R., Malaga-Trillo, E., Veith, M., & Meyer, A. (2003). Complete nucleotide sequence of the mitochondrial genome of a salamander, Mertensiella luschani. Gene, 317, 17–27. doi: 10.1016/S0378-1119(03)00655-3.PubMedCrossRefGoogle Scholar
  95. Zhang, P., Chen, Y. Q., Zhou, H., Wang, X. L., & Qu, L. H. (2003). The complete mitochondrial genome of a relic salamander, Ranodon sibiricus (Amphibia: Caudata) and implications for amphibian phylogeny. Molecular Phylogenetics and Evolution, 28(3), 620–626. doi: 10.1016/S1055-7903(03)00059-9.PubMedCrossRefGoogle Scholar
  96. Zhang, P., Zhou, H., Chen, Y.-Q., Liu, Y.-F., & Qu, L.-H. (2005). Mitogenomic perspectives on the origin and phylogeny of living amphibians. Systematic Biology, 54(3), 391–400. doi: 10.1080/10635150590945278.PubMedCrossRefGoogle Scholar

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© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary MedicineUniversity of CalgaryCalgaryCanada

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