Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-28T17:09:00.134Z Has data issue: false hasContentIssue false
  • English
  • Français

The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution

Published online by Cambridge University Press:  03 November 2011

M. I. Coates
M. I. Coates
Affiliation:
Medawar Building, Department of Biology,University College London, Gower Street, London WCIE 6BT.
Get access Rights & Permissions [Opens in a new window]

Abstract

The postcranial skeleton of Acanthostega gunnari from the Famennian of East Greenland displays a unique, transitional, mixture of features conventionally associated with fishand tetrapod-like morphologies. The rhachitomous vertebral column has a primitive, barely differentiated atlas-axis complex, encloses an unconstricted notochordal canal, and the weakly ossified neural arches have poorly developed zygapophyses. More derived axial skeletal features include caudal vertebral proliferation and, transiently, neural radials supporting unbranched and unsegmented lepidotrichia. Sacral and post-sacral ribs reiterate uncinate cervical and anterior thoracic rib morphologies: a simple distal flange supplies a broad surface for iliac attachment. The octodactylous forelimb and hindlimb each articulate with an unsutured, foraminate endoskeletal girdle. A broad-bladed femoral shaft with extreme anterior torsion and associated flattened epipodials indicates a paddle-like hindlimb function. Phylogenetic analysis places Acanthostega as the sister-group of Ichthyostega plus all more advanced tetrapods. Tulerpeton appears to be a basal stemamniote plesion, tying the amphibian-amniote split to the uppermost Devonian. Caerorhachis may represent a more derived stem-amniote plesion. Postcranial evolutionary trends spanning the taxa traditionally associated with the fish-tetrapod transition are discussed in detail. Comparison between axial skeletons of primitive tetrapods suggests that plesiomorphic fish-like morphologies were re-patterned in a cranio-caudal direction with the emergence of tetrapod vertebral regionalisation. The evolution of digited limbs lags behind the initial enlargement of endoskeletal girdles, whereas digit evolution precedes the elaboration of complex carpal and tarsal articulations. Pentadactylous limbs appear to have stabilised independently in amniote and amphibian lineages; the colosteid Greererpeton has a pentadactylous manus, indicating that basal amphibian forelimbs may not be restricted to patterns of four digits or less.

Keywords

East Greenlandphylogenyaxial skeletongirdleslimbspolydactyly
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 87 , Issue 3 , 1996 , pp. 363 - 421
Copyright
Copyright © Royal Society of Edinburgh 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abel, O. 1911. Grundzüge der Palaeobiologie der Wirbeltiere. Stuttgart: Schweizerbart.Google Scholar
Ahlberg, P. E. 1991. Tetrapod or near-tetrapod fossils from the Upper Devonian of Scotland. NATURE 354, 298–301.CrossRefGoogle Scholar
Ahlberg, P. E. 1995. Elginerpeton pancheni and the earliest tetrapod clade. NATURE 373, 421–4.Google Scholar
Ahlberg, P. E. (in press). Spare parts for Elginerpeton? The postcranial stem tetrapod remains from Scat Craig, Morayshire, Scotland. ZOOL J LINN SOC.Google Scholar
Ahlberg, P. E. & Milner, A. R. 1994. The origin and early diversification of tetrapods. NATURE 368, 507–14.Google Scholar
Ahlberg, P. E. & Trewin, N. H. 1995. The postcranial skeleton of the Middle Devonian lungfish Dipterus valenciennesi. TRANS R SOC EDINBURGH EARTH SCI 85, 159–75.CrossRefGoogle Scholar
Ahlberg, P. E., Luksevics, E. & Lebedev, O. A. 1994. The first tetrapod finds from the Devonian (Upper Famennian) of Latvia. PHILOS TRANS R SOC LONDON B343, 303–2847.CrossRefGoogle Scholar
Altangerel, P., Norell, M. A., Chiappe, L. M. & Clarke, J. M. 1993. Flightless bird from the Cretaceous of Mongolia. NATURE 362, 623–6; correction 363, 188.CrossRefGoogle Scholar
Andrews, S. M. & Carroll, R. L. 1991. The Order Adelospondyli: Carboniferous lepospondyl amphibians. TRANS R SOC EDINBURGH EARTH SCI 82, 239–75.CrossRefGoogle Scholar
Andrews, S. M. & Westoll, T. S. 1970a. The postcranial skeleton of Eusthenopteron foordi Whiteaves. TRANS R SOC EDINBURGH 68, 207–329.Google Scholar
Andrews, S. M. & Westoll, T. S. 1970b. The postcranial skeleton of rhipidistian fishes excluding Eusthenopteron. TRANS R SOC EDINBURGH 68, 391–489.CrossRefGoogle Scholar
Ashley-Ross, M. A. 1992. The comparative myology of the thigh and crus in the salamanders Ambystoma tigrinum and Dicamptodon tenebrosus. J MORPHOL 211, 147–63.Google Scholar
Bartsch, B. & Gemballa, S. 1992. On the anatomy and development of the vertebral column and pterygiophores in Polypterus senegalus Cuvier, 1829 (‘Pisces’, Polypteriformes). ZOOL JB ANAT 122, 497–529.Google Scholar
Beaumont, E. H. 1977. Cranial morphology of the Loxommatidae (Amphibia: Labyrinthodontia). PHILOS TRANS R SOC LONDON B280, 29–101.Google Scholar
Bendix-Almgreen, S. E. 1976. Palaeovertebrate faunas of Greenland. In Escher, A. & Watt, W. S. (eds) Geology of Greenland, 536–73. Copenhagen: Geol. Surv. Greenland.Google Scholar
Bendix-Almgreen, S. E., Clack, J. A. & Olsen, H. 1988. Upper Devonian and Permian vertebrates collected in 1987 around Kejser Franz Joseph Fjord, central East Greenland. RAPP GRØNLANDS GEOL UNDERS 140, 95–102.Google Scholar
Bendix-Almgreen, S. E., Clack, J. A. & Olsen, H. 1990. Upper Devonian tetrapod palaeoecology in the light of new discoveries in East Greenland. TERRA NOVA 2, 131–7.Google Scholar
Benton, M. J. 1990. Vertebrate Palaeontology. London: Unwin Hyman.Google Scholar
Blanco, M. J. & Alberch, P. 1992. Caenogenesis, developmental variability, and evolution in the carpus and tarsus of the marbled newt Triturus marmoratus. EVOLUTION 46, 677–87.CrossRefGoogle ScholarPubMed
Bolt, J. R. 1977. Dissorophid relationships and ontogeny, and the origin of the Lissamphibia. J PALEONTOL 51, 235–49.Google Scholar
Bolt, J. R. 1990. Mississippian vertebrates from Iowa. NAT GEOGR RES 6, 339–54.Google Scholar
Bolt, J. R. 1991. Lissamphibian origins. In Schultze, H.-P. & Trueb, L. (eds) Origins of the higher groups of Tetrapods: controversy and consensus, 194–222. Ithaca and London: Comstock Publishing Associates.Google Scholar
Brainerd, E. L., Ditelberg, J. S. & Bramble, D. M. 1993. Lung ventilation in salamanders and the evolution of vertebrate air-breathing mechanisms. BIOL J LINN SOC 49, 163–83.CrossRefGoogle Scholar
Burke, A. C., Nelson, C. & Tabin, C. J. 1994. Hox genes and vertebrate transposition. J MORPH 220, 331.Google Scholar
Burke, A. C., Nelson, C. & Tabin, C. J. 1995. Hox genes and the evolution of vertebrate axial morphology. DEVELOPMENT 121, 333–46.CrossRefGoogle ScholarPubMed
Bystrov, A. P. & Efremov, I. A. 1940. Benthosuchus sushkini Efr.—A labyrinthodont from the Eotriassic of Sharjenga River. TRUDY PALEONTOL INST 10, 5–152.Google Scholar
Campbell, K. S. W. & Bell, M. W. 1977. A primitive amphibian from the late Devonian of New South Wales. ALCHERINGA 1, 369–81.CrossRefGoogle Scholar
Carroll, R. L. 1969. Problems of the origin of reptiles. BIOL REVS 44, 393–432.Google Scholar
Carroll, R. L. 1988. Vertebrate paleontology and evolution. New York: W. H. Freeman & Co.Google Scholar
Carroll, R. L. 1995. Problems of the phylogenetic analysis of Paleozoic choanates. In Arsenault, M., Lelièvre, H., & Janvier, P. (eds) Studies on early vertebrates (VIIth International Symposium, Miguasha Pare, Quebec). BULL MUS NATL HIST NAT, PARIS 17, (C) 389–445.Google Scholar
Carroll, R. L. & Gaskill, P. 1978. The Order Microsauria. MEM AM PHILOS SOC 126, 1–211.Google Scholar
Carroll, R. L., Belt, E., Dineley, D. L., Baird, D. & Mcgregor, D. C. 1972. Excursion A59, Vertebrate paleontology of eastern Canada. 24TH INT GEOL CONGR, MONTREAL, 1972, 1–113.Google Scholar
Clack, J. A. 1987. Pholiderpeton scutigerum Huxley, an amphibian from the Yorkshire coal measures. PHILOS TRANS R SOC LONDON B318, 1–107.Google Scholar
Clack, J. A. 1988. New material of the early tetrapod Acanthostega from the Upper Devonian of East Greenland. PALAEONTOLOGY 31, 699–724.Google Scholar
Clack, J. A. 1989. Discovery of the earliest tetrapod stapes. NATURE 342, 425–30.Google Scholar
Clack, J. A. 1992. The stapes of Acanthostega gunnari and the role of the stapes in early tetrapods. In Webster, D., Fay, R. R., & Popper, A. N. (eds) Evolutionary biology of hearing, 405–20. New York: Springer Verlag.Google Scholar
Clack, J. A. 1993. Homologies in the fossil record: the middle ear as a test case. ACTA BIOTHEORETICA 41, 391–410.CrossRefGoogle ScholarPubMed
Clack, J. A. 1994a. Acanthostega gunnari, a Devonian tetrapod from Greenland; the snout, palate and ventral parts of the braincase, with a discussion of their significance. MEDD GRØNLAND GEOSCI 31, 3–24.Google Scholar
Clack, J. A. 1994b. The earliest known tetrapod braincase and the evolution of the stapes and fenestra ovalis. NATURE 369, 392–4.CrossRefGoogle Scholar
Clack, J. A. (in press). The neurocranium of Acanthostega gunnari Jarvik and the evolution of the auditory region in tetrapods. ZOOL J LINN SOC.Google Scholar
Clack, J. A. & Coates, M. I. 1993. Acanthostega gunnari: our present connection. In Hoch, E. & Brantsen, A. K. (eds) Deciphering the natural world and the role of collections and museums, 39–42. Copenhagen: Geological Museum.Google Scholar
Clack, J. A. & Coates, M. I. 1995. Acanthostega gunnari, a primitive, aquatic tetrapod? In Arsenault, M., Lelièvre, H., & Janvier, P. (eds) Studies on early vertebrates (VIIth International Symposium, Miguasha Pare, Quebec). BULL MUS NATL HIST NAT, PARIS 17, (C) 359–72.Google Scholar
Cloutier, R. & Ahlberg, P. E. 1995. Sarcopterygian interrelationships: how far are we from a phylogenetic consensus. GEOBIOS 19, 241–8.Google Scholar
Coates, M. I. 1991. New palaeontological contributions to limb ontogeny and phylogeny. In Hinchliffe, J. R., Hurle, J. M. & Summerbell, D. (eds) Developmental patterning of the vertebrate limb, 325–37. New York: Plenum.CrossRefGoogle Scholar
Coates, M. I. 1993. Ancestors and homology. The origin of the tetrapod limb. ACTA BIOTHEORETICA 41, 411–24.CrossRefGoogle ScholarPubMed
Coates, M. I. 1994a. Evolutionary patterns and early tetrapod limbs. J MORPH 220, 334.Google Scholar
Coates, M. I. 1994b. The origin of vertebrate límbs. In Akam, M., Holland, P., Ingham, P. & Wray, G. (eds) The evolution of developmental mechanisms, 169–80. DEVELOPMENT (SUPPL) 1994.Google Scholar
Coates, M. I. 1995. Fish fins or tetrapod limbs—a simple twist of fate? CURR BIOL 5, 844–8.CrossRefGoogle ScholarPubMed
Coates, M. I. & Clack, J. A. 1990. Polydactyly in the earliest known tetrapod limbs. NATURE 347, 66–9.CrossRefGoogle Scholar
Coates, M. I. & Clack, J. A. 1991. Fish-like gills and breathing in the earliest known tetrapod. NATURE 352, 234–6.CrossRefGoogle Scholar
Coates, M. I. & Clack, J. A. 1995. Romer's gap: tetrapod origins and terrestriality. In Arsenault, M., Lelièvre, H. & Janvier, P. (eds) Studies on early vertebrates (VIIth International Symposium, Miguasha Pare, Quebec). BULL MUS NATL HIST NAT, PARIS 17, (C) 373–88.Google Scholar
Cook, J. 1990. Proper names for early fingers. NATURE 347, 14–15.CrossRefGoogle Scholar
Daeschler, E. B., Shubin, N. H., Thomson, K. S. & Amaral, W. W. 1994. A Devonian tetrapod from North America. SCIENCE 265, 639–42.CrossRefGoogle ScholarPubMed
Daeschler, E. B. & Shubin, N. 1995. Tetrapod origins. PALEOBIOLOGY 21, 404–9.Google Scholar
Duboule, D. 1994. How to make a limb? SCIENCE 226, 575–6.CrossRefGoogle Scholar
Edwards, J. L. 1989. Two perspectives on the evolution of the-tetrapod limb. AM ZOOL 29, 235–54.CrossRefGoogle Scholar
Farris, J. S. 1969. A successive approximation approach to character weighting. SYST ZOOL 18, 374–85.CrossRefGoogle Scholar
Forey, P., Gardiner, B. G. & Patterson, C. 1991. The Lungfish, the Coelacanth, and the Cow revisited. In Schultze, H.-P. & Treub, L. (eds) Origins of the higher groups of tetrapods: controversy and consensus, 145–72. New York: Cornell University Press.Google Scholar
Friend, P. F., Alexander-Marrak, P. D., Nicholson, J. & Yeats, A. K. 1976. Devonian sediments of East Greenland II. Sedimentary structures and fossils. MEDD GRØNLAND 206, 99pp.Google Scholar
Francis, E. T. 1934. The anatomy of the salamander. Oxford: Clarendon Press.Google Scholar
Gaffney, E. S. 1979. Tetrapod monophyly: a phylogenetic analysis. BULL CARNEGIE MUS NATL HIST 13, 92–105.Google Scholar
Gaunt, S. J. 1994. Conservation in the Hox code during morphological evolution. INT J DEV BIOL 38, 549–52.Google ScholarPubMed
Gauthier, J. A., Kluge, A. G. & Rowe, T. 1988. Amniote phylogeny and the importance of fossils. CLADISTICS 4, 105–209.Google Scholar
Godfrey, S. J. 1989. The postcranial skeletal anatomy of the Carboniferous tetrapod Greererpeton burkemorani Romer, 1969. PHILOS TRANS R SOC LONDON B323, 75–133.Google Scholar
Godfrey, S. J., Fiorillo, A. R. & Carroll, R. L. 1987. A newly discovered skull of the temnospondyl amphibian Dendrerpeton acadianum Owen. CAN J EARTH SCI 24, 796–805.CrossRefGoogle Scholar
Godfrey, S. J. & Reisz, R. R. 1991. The vertebral morphology of Gephyrostegus bohemicus Jaekel 1902, with comments on the atlas-axis complex in primitive tetrapods. HISTORICAL BIOL 5, 27–36.CrossRefGoogle Scholar
Goodrich, E. S. 1904. On the dermal fin-rays of fishes, living and extinct. Q J MICROSP SCI 47, 465–522.Google Scholar
Goodrich, E. S. 1906. Notes on the development, structure and origin of the median and paired fins of fish. Q J MICROSP SCI 50, 333–76.Google Scholar
Goodrich, E. S. 1916. On the classification of the Reptilia. PROC R SOC LONDON B89, 261–76.Google Scholar
Goodrich, E. S. 1930. Studies on the structure and development of vertebrates. London: Macmillan & Co.CrossRefGoogle Scholar
Goulding, M., Leal, Carvalho M. & Ferreira, E. G. 1988. Rio Negro, rich life in poor water. Illinois/Netherlands: SPB Academic Publishing.Google Scholar
Haswell, W. A. 1882. On the structure of the paired fins of Ceratodus, with remarks on the general theory of the vertebrate limb. PROC LINN SOC NEW SOUTH WALES 7, 2–11.CrossRefGoogle Scholar
Holmes, R. 1980. Proterogyrinus scheelei and the early evolution of the labyrinthodont pectoral limb. In Panchen, A. L. (ed.) The terrestrial environment and the origin of land vertebrates, 351–76. London and New York: Academic Press.Google Scholar
Holmes, R. 1984. The Carboniferous amphibian Proterogyrinus scheelei Romer, and the early evolution of tetrapods. PHILOS TRANS R SOC LONDON B306, 431–527.Google Scholar
Holmes, R. 1989. The skull and axial skeleton of the Lower Permian anthracosauroid amphibian Archeria crassidica Cope. PALAEONTOGRAPHICA 207, 161–206.Google Scholar
Holmes, R. & Carroll, R. L. 1977. A temnospondyl amphibian from the Mississippian of Scotland. BULL MUS COMP ZOOL HARVARD 147, 489–511.Google Scholar
Hook, R. W. 1983. Colosteus scutellus (Newberry), a primitive temnospondyl amphibian from the Middle Pennsylvanian of Linton, Ohio. AM MUS NOVIT 2770, 1–41.Google Scholar
Jarvik, E. 1942. On the structure of the snout of crossopterygians and lower gnathostomes in general. ZOOL BIDR UPPS 21, 235–675.Google Scholar
Jarvik, E. 1952. On the fish-like tail in the ichthyostegid stegocephalians with descriptions of a new stegocephalian and a new crossopterygian from the Upper Devonian of East Greenland. MEDDR GRØNLAND 114, 1–90.Google Scholar
Jarvik, E. 1955. The oldest tetrapods and their forerunners. SCI MONTHLY 80, 141–54.Google Scholar
Jarvik, E. 1980. Basic structure and evolution of vertebrates 1, 1–591. London and New York: Academic Press.Google Scholar
Jarvik, E. 1996. The Devonian tetrapod Ichthyostega. FOSSILS & STRATA 40, 1–206.CrossRefGoogle Scholar
Klembara, J. 1995. The external gills and ornamentation of skull roof bones of the Lower Permian tetrapod Discosauriscus Kuhn 1933) with remarks to its ontogeny. PALÄONT Z 69, 265–81.Google Scholar
Kodera, H. 1994. Jurassic fishes. New Jersey: TFH Publications.Google Scholar
Laurin, M. (1996). Redescription of the cranial anatomy of Seymouria baylorensis, the best known seymouriamorph (Vertebrata: Seymouriamorpha). PALEOBIOS, 17, 1–16.Google Scholar
Laurin, M. & Reisz, R. R. 1995. A reevaluation of early amniote phylogeny. ZOOL J LINN SOC 113, 165–223.Google Scholar
Lebedev, O. A. 1984. The first find of a Devonian tetrapod in USSR. DOKLADY AKAD NAUK SSSR 278, 1407–73 [In Russian].Google Scholar
Lebedev, O. A. 1985. The first tetrapods: searches and findings. PRIRODA 1985 11, 26–36. [In Russian].Google Scholar
Lebedev, O. A. 1990. Tulerpeton, l'animal à six doigts. LA RECHERCHE 225, 1274–75.Google Scholar
Lebedev, O. A. 1992. The latest Devonian, Khovanian vertebrate assemblage of Andreyevka-2 locality, Tula Region, Russia. In Mark-Kurik, E. (ed.) Fossil fishes as living animals, 265–72. Proceedings of the IInd International Colloquium on the study of Palaeozoic Fishes, Tallin, 1989. ACADEMIA 1. Tallin: Academy of Sciences of Estonia.Google Scholar
Lebedev, O. A. & Clack, J. A. 1993. Upper Devonian tetrapods from Andreyevka, Tula Region, Russia. PALAEONTOLOGY 36, 721–34.Google Scholar
Lebedev, O. A. & Coates, M. I. 1995. The postcranial skeleton of the Devonian tetrapod Tulerpeton curtum Lebedev. ZOOL J LINN SOC 113, 307–48.CrossRefGoogle Scholar
Leonardi, G. 1983. Notopus petri nov. gen., nov. sp.: Une empreinte d'amphibien de Devonian au Parana (Brésil). GEOBIOS 16, 233–9.CrossRefGoogle Scholar
Lewis, J. & Martin, P. 1989. Limbs: a pattern emerges. NATURE 342, 734–5.CrossRefGoogle ScholarPubMed
Linnaeus, C. 1758. Systema naturae (10th edn). Stockholm: Laurentii Salvii.Google Scholar
Lombard, R. E. & Bolt, J. R. 1995. A new primitive tetrapod Whatcheeria deltae from the Lower Carboniferous of Iowa. PALAEONTOLOGY 38, 471–94.Google Scholar
Lombard, R. E. & Sumida, S. S. 1992. Recent progress in understanding early tetrapods. AM ZOOL 32, 609–22.Google Scholar
Long, J. A. 1989. A new rhizodontiform fish from the early Carboniferous of Victoria, Australia, with remarks on the phylogenetic position of the group. J VERT PALEONTOL 9, 1–17.CrossRefGoogle Scholar
Long, J. A. 1990. Heterochrony and the origin of tetrapods. LETHAIA 23, 157–66.CrossRefGoogle Scholar
McNamara, K. J. 1986. A guide to the nomenclature of heterochrony. J PALEONTOL 60, 4–13.Google Scholar
Meyer, A. 1995. Molecular evidence on the origin of tetrapods and the relationships of the coelacanth. TREE 10, 111–16.Google ScholarPubMed
Milner, A. R. 1980. The temnospondyl amphibian Dendrerpeton from the Upper Carboniferous of Ireland. PALAEONTOLOGY 23, 125–41.Google Scholar
Milner, A. R. 1988. The relationships and origin of living amphibia. In Benton, M. J. (ed.) The phylogeny and classification of the tetrapods, 1, 59–102. Oxford: Clarendon Press.Google Scholar
Milner, A. R. 1990. The radiations of temnospondyl amphibians. In Taylor, P. D. & Larwood, G. P. (eds) Major evolutionary radiations, 321–49. Oxford: Clarendon Press.Google Scholar
Milner, A. R. & Sequeira, S. E. K. 1994. The temnospondyl amphibians from East Kirkton, West Lothian, Scotland. TRANS R SOC EDINBURGH EARTH SCI 84, 331–61.Google Scholar
Milner, A. R., Smithson, T. R., Milner, A. C., Coates, M. I., & Rolfe, W. D. I. 1986. The search for early tetrapods. MOD GEOL 10, 1–28.Google Scholar
Molven, A., Wright, C. V., Bremiller, R., DeRobertis, E. M. & Kimmel, C. B. 1990. Expression of a homeobox gene product in normal and mutant zebrafish embryos: evolution of the tetrapod body plan. DEVELOPMENT 109, 279–88.Google Scholar
Moulton, J. M. 1974. A description of the vertebral-column of Eryops based on the notes and drawings of A. S. Romer. BREVIORA 428, 1–44.Google Scholar
Nelson, C. E., Morgan, B. A., Burke, A. C., Laufer, E., DiMambro, E., Murtaugh, L. C., Gonzales, E., Tessarollo, L., Parada, L. F. & Tabin, C. 1996. Analysis of Hox gene expression in the chick limb bud. DEVELOPMENT 122, 1449–66.CrossRefGoogle ScholarPubMed
Nicholson, J. & Friend, P. F. 1976. Devonian sediments of East Greenland V. The central sequence, Kap Graah Group and Mount Celsius Supergroup. MEDDR GRØNLAND 206, 1–117.Google Scholar
Olsen, E. C. 1936. The ilio-sacral attachment of Eryops. J PALEONTOL 10, 648–51.Google Scholar
Panchen, A. L. 1966. The axial skeleton of the labyrinthodont Eogyrinus attheyi. J ZOOL LONDON 150, 199–220.Google Scholar
Panchen, A. L. 1985. On the amphibian Crassigyrinus scoticus Watson from the Carboniferous of Scotland. PHILOS TRANS R SOC LONDON B309, 505–68.Google Scholar
Panchen, A. L. 1988. In search of earliest tetrapods. NATURE 333, 704.Google Scholar
Panchen, A. L. 1992. Classification, evolution, and the nature of biology. New York: Cambridge University Press.Google Scholar
Panchen, A. L. & Smithson, T. R. 1988. The relationships of early tetrapods. In Benton, M. J. (ed.) The phylogeny and classification of the tetrapods, 1, 1–32. Oxford: Clarendon Press.Google Scholar
Panchen, A. L. & Smithson, T. R. 1990. The pelvic girdle and hind limb of Crassigyrinus scoticus (Lydekker) from the Scottish Carboniferous and the origin of the tetrapod pelvic skeleton. TRANS R SOC EDINBURGH EARTH SCI 81, 31–44.CrossRefGoogle Scholar
Patterson, C. 1975. The braincase of pholidophorid and leptolepid fishes, with a review of the actinopterygian braincase. PHILOS TRANS R SOC LONDON B269, 275–579.Google Scholar
Patterson, C. 1993a. Bird or dinosaur? NATURE 365, 21–2.CrossRefGoogle Scholar
Patterson, C. 1993b. Naming names. NATURE 366, 518.Google Scholar
Patterson, C. & Rosen, D. E. 1977. Review of ichthyodectiform and other Mesozoic teleost fishes and the theory and practice of classifying fossils. BULL AM MUS NAT HIST 158, 81–172.Google Scholar
Pendleton, J. W., Nagai, B. K., Murtha, M. T. & Ruddle, F. H. 1993. Expansion of the Hox gene family and the evolution of chordates. P N A S 90, 6300–4.Google Scholar
Pridmore, P. A. 1995. Submerged walking in the epaulette shark Hemiscyllium ocellatum (Hemiscyllidae) and its implications for locomotion in rhipidistian fishes and early tetrapods. ZACS ZOOL 98, 278–97.Google Scholar
de Quieroz, K. & Gauthier, J. 1992. Phylogenetic taxonomy. ANN REV ECOL SYST 23, 449–80.Google Scholar
Rackoff, J. S. 1980. The origin of the tetrapod limb and the ancestry of tetrapods. In Panchen, A. L. (ed.) The terrestrial environment and the origin of land vertebrates, 255–92. SYSTEMAT1CS ASSOC SPEC VOL 15. London: Academic Press.Google Scholar
Reilly, S. M. & Lauder, G. V. 1990. The evolution of tetrapod feeding behaviour: kinematic homologies in prey transport. EVOLUTION 44, 1542–57.Google Scholar
Rogers, D. 1990. Probable tetrapod tracks rediscovered in the Devonian of North Scotland. J GEOL SOC LONDON 147, 746–8.CrossRefGoogle Scholar
Romer, A. S. 1922. The locomotor apparatus of certain primitive and mammal-like reptiles. BULL AM MUS NAT HIST 46, 517–606.Google Scholar
Romer, A. S. 1956. Osteology of the reptiles. Chicago: University of Chicago Press.Google Scholar
Romer, A. S. 1957. The appendicular skeleton of the Permian embolomerous amphibian Archeria. CONTRIB MUS GEOL UNIV MICHIGAN 13, 103–59.Google Scholar
Romer, A. S. & Parsons, T. S. 1977. The vertebrate-body (5th edn). Philadelphia: W. B. Saunders Company.Google Scholar
Romer, A. S. & Price, L. I. 1940. Review of the Pelycosauria. SPEC PAP GEOL SOC AM 28, 1–538.Google Scholar
Ruddle, F. H., Bartels, J. L., Bentley, K. L., Kappen, C., Murtha, M. T. & Pendleton, J. W. 1994. Evolution of Hox genes. ANN REV GEN 28, 423–42.Google ScholarPubMed
Säve-Söderbergh, G. 1932. Preliminary note on Devonian stegocephalians from East Greenland. MEDDR GRØNLAND 94, 1–107.Google Scholar
Säve-Söderbergh, G. 1934. Some points of view concerning the evolution of vertebrates and the classification of this group. ARK ZOOL 26A, 1–20.Google Scholar
Sayer, M. D. J. & Davenport, J. 1991. Amphibious fish: why do they leave the water? REV FISH BIOL FISHERIES 1, 159–81.CrossRefGoogle Scholar
Schultze, H.-P. 1994. Comparison of hypotheses on the relationships of sarcopterygians. SYST BIOL 43, 155–73.Google Scholar
Schultze, H.-P. & Arsenault, M. 1985. The panderichthyid fish Elpistostege: a close relative of tetrapods? PALAEONTOLOGY 28, 293–310.Google Scholar
Shear, W. A. 1991. The early development of terrestrial ecosystems. NATURE 351, 283–9.CrossRefGoogle Scholar
Shubin, N. H. 1995. The evolution of paired fins and the origin of tetrapod limbs. Phylogenetic and transformational approaches. EVOL BIOL 28, 39–86.CrossRefGoogle Scholar
Shubin, N. H. & Alberch, P. 1986. A morphogenetic approach to the origin and basic organisation of the tetrapod limb. EVOL BIOL 20, 319–87.Google Scholar
Smith, A. B. 1994. Systematics and the fossil record: documenting evolutionary patterns. London: Blackwell Scientific Publications.CrossRefGoogle Scholar
Smithson, T. R. 1982. The cranial morphology and relationships of Greererpeton burkemorani Romer (Amphibia: Temnospondyli). ZOOL J LINN SOC 76, 29–90.CrossRefGoogle Scholar
Smithson, T. R. 1985. The morphology and relationships of the Carboniferous amphibian Eoherpeton watsoni Panchen. ZOOL J LINN SOC 85, 317–410.CrossRefGoogle Scholar
Smithson, T. R. 1986. A new anthracosaur amphibian from the Carboniferous of Scotland. PALAEONTOLOGY 29, 603–28.Google Scholar
Smithson, T. R. 1994. Eldeceeon rolfei, a new reptiliomorph from the Visean of East Kirkton, West Lothian, Scotland. TRANS R SOC EDINBURGH EARTH SCI 84, 377–82.Google Scholar
Smithson, T. R., Carroll, R. L., Panchen, A. L. & Andrews, S. M. 1994. Westlothiana lizziae from the Visean of East Kirkton, West Lothian, Scotland and the amniote stem. TRANS R SOC EDINBURGH EARTH SCI 84, 377–82.Google Scholar
Smithson, T. R. & Thomson, K. S. W. 1982. The hyomandibular of Eusthenopteron foordi Whiteaves (Pisces: Crossopterygii) and the early evolution of the tetrapod stapes. ZOOL J LINN SOC 74, 93–103.CrossRefGoogle Scholar
Sordino, P. & Duboule, D. 1996. A molecular approach to the evolution of vertebrate paired appendages. TREE 11, 114–19.Google Scholar
Sordino, P., van der Hoeven, F. & Duboule, D. 1995. Hox gene expression in teleost fins and the origin of vertebrate digits. NATURE 375, 678–81.CrossRefGoogle ScholarPubMed
Stossel, I. 1995. The discovery of a new Devonian tetrapod trackway in SW Ireland. J GEOL SOC LONDON 152, 407–13.Google Scholar
Swofford, D. L. 1990. PAUP, Phylogenetic Analysis Using Parsimony, Version 3.1 (Computer program: Apple Macintosh version). Illinois Natural History Survey.Google Scholar
Symmons, S. 1979. Notochordal and elastic components of the axial skeleton of fishes and their functions in locomotion. J ZOOL LONDON 189, 157–206.CrossRefGoogle Scholar
Tabin, C. J. 1992. Why we have (only) five fingers per hand: Hox genes and the evolution of paired limbs. DEVELOPMENT 116, 289–296.Google Scholar
Thorogood, P. 1991. The development of the Teleost fin and implications for our understanding of tetrapod limb evolution. In Hinchliffe, J. R., Hurle, J. M. & Summerbell, D. (eds) Developmental patterning of the vertebrate limb, 347–54. New York: Plenum.Google Scholar
Tickle, C. 1995. Vertebrate limb development. CURR OPIN GEN DEV 5, 478–84.CrossRefGoogle ScholarPubMed
Tickle, C. & Eichele, G. 1994. Vertebrate limb development. ANN REV CELL BIOL 10, 121–52.CrossRefGoogle ScholarPubMed
Vorobyeva, E. 1992. The problem of the terrestrial vertebrate origin. Moscow: Nauka.Google Scholar
Vorobyeva, E. & Schultze, H.-P. 1991. Description and systematics of panderichthyid fishes with comments on their relationship to tetrapods. In Schultze, H.-P. & Treub, L. (eds) Origins of the higher groups of tetrapods, 68–109. Ithaca: Comstock, Cornell University Press.Google Scholar
Wagner, G. P. 1989. The origin of morphological characters and the biological basis of homology. EVOLUTION 43, 1157–71.CrossRefGoogle ScholarPubMed
Warren, A. A., Jupp, R. & Bolton, B. R. 1986. Earliest tetrapod trackway. ALCHERINGA 10, 183–6.CrossRefGoogle Scholar
Warren, J. W. & Wakefield, N. A. 1972. Trackways of tetrapod vertebrates from the Upper Devonian of Victoria, Australia. NATURE 238, 469–70.CrossRefGoogle Scholar
Watson, D. M. S. 1914. On a femur of reptilian type from the Lower Carboniferous of Scotland. GEOL MAG (6) 1, 347–8.CrossRefGoogle Scholar
Wellstead, C. F. 1982. A Lower Carboniferous aïstopod amphibian from Scotland. PALAEONTOLOGY 25, 193–208.Google Scholar
Wettstein, O. 1931. Ordnung der Klasse Reptilia: Rhynchocephalia. In Kükenthal, W. & Krumbach, T. (eds) Handbuch Der Zoologie VII, 1–128. Berlin & Leipzig: Walter Der Gruyter & Co.Google Scholar
White, T. E. 1939. Osteology of Seymouria baylorensis Broili. BULL MUS COMP ZOOL 85, 325–409.Google Scholar
Woodrow, D. L., Robinson, R. A. J., Prave, A. R., Traverse, A., Deaschler, E. B., Rowe, N. D. & DeLaney, M. A. 1995. Stratigraphic, sedimentologic, and temporal framework of Red Hill (Upper Devonian Catskill Formation) near Hyner, Clinton County, Pennsylvania: Site of the oldest amphibian known from North America. 60th Annual Field Conference of Pennsylvania Geologists.Google Scholar