Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-30T15:33:54.587Z Has data issue: false hasContentIssue false

The postcranial skeleton of Trimerorhachis insignis Cope, 1878 (Temnospondyli: Trimerorhachidae): A plesiomorphic temnospondyl from the Lower Permian of North America

Published online by Cambridge University Press:  14 July 2015

Kat Pawley*
Affiliation:
Department of Zoology, La Trobe University, Melbourne, VIC 3086 Australia.

Abstract

The postcranial skeleton of the Lower Permian temnospondyl Trimerorhachis insignis Cope, 1878 is described and figured in detail. Postcranial adaptations for an aquatic existence in T. insignis include the extensive ventral expansion of the interclavicle and clavicles and poorly ossified ends of the endochondral bones. The endochondral postcranial skeleton of T. insignis is paedomorphic through the process of neoteny, retaining an osteologically immature condition throughout morphogenesis. The endochondral postcranial elements display progressive morphological changes that do not stabilize in larger specimens, indicating indeterminate growth, with a correlation between size and degree of ossification. Some postcranial characteristics are present only in later morphogenetic stages of T. insignis.

Within the Temnospondyli, the postcranial skeleton of T. insignis is most similar to that of other members of the Dvinosauria. The morphology of the postcranial skeleton of T. insignis is consistent with a phylogenetic position more derived than the basal temnospondyls Balanerpeton woodi and Dendrerpeton acadianum, but less derived than the Euskelia plus Stereospondylomorpha. A sister-taxon relationship between the Dvinosauria and brachyopoids is not supported by postcranial characteristics of T. insignis.

Characteristics that develop last in morphogenesis in temnospondyls, and are consequently only present in well-ossified, morphogenetically mature temnospondyls, are absent in T. insignis due to paedomorphosis. Otherwise, the postcranial skeletons of T. insignis and other aquatic temnospondyls are similar to that of terrestrial temnospondyls, supporting the hypothesis that aquatic temnospondyls had terrestrial ancestors and are thus secondarily aquatic.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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

Amalitzky, W. P. 1921. Dvinosauridae. North Dvina Excavations of Prof. Amalitzky. Russian Akademii Nauk, Petrograd, 16 p.Google Scholar
Bakker, R. T. 1982. Juvenile-adult habitat shift in Permian fossil reptiles and amphibians. Science, 217:5355.CrossRefGoogle ScholarPubMed
Behrensmeyer, A. K. 1975. The taphonomy and paleoecology of Plio-Pleistocene vertebrate assemblages from fluvial environments. Bulletin of the Museum of Comparative Zoology, Harvard College, 146:473578.Google Scholar
Behrensmeyer, A. K. 1988. Vertebrate preservation in fluvial channels. Palaeogeography, Palaeoclimatology, Palaeoecology, 63:183199.Google Scholar
Behrensmeyer, A. K. 1991. Terrestrial vertebrate accumulations, p. 291335. In Allison, P. A. and Briggs, D. E. G. (eds.), Taphonomy: Releasing the Data Locked in the Fossil Record. Volume 9. Plenum Press, New York.CrossRefGoogle Scholar
Berman, D. S. and Reisz, R. R. 1980. A new species of Trimerorhachis (Amphibia, Temnospondyli) from the Lower Permian Abo Formation of New Mexico, with discussion of Permian faunal distributions in that state. Annals of the Carnegie Museum, 49:455485.Google Scholar
Boy, J. A. 1972. Die Branchiosauridae (Amphibia) des saarpfälzischen Rotiegenden (Perm, SW-Deutschland). Abhandlungen des hessischen Landesamts für Bodenforschung, 65, 137 p.Google Scholar
Boy, J. A. 1988. Über einige Vertreter der Eryopoidea (Amphibia: Temnospondyli) aus dem Europäischen Rotliegend (höchstes Karbon- Perm). 1. Sclerocephalus . Paläontologische Zeitschrift, 62:107132.Google Scholar
Boy, J. A. 1993. Über einige Vertreter der Eryopoidea (Amphibia: Temnospondyli) aus dem Europäischen Rotliegend (höchstes Karbon-Perm). 4. Cheliderpeton . Paläontologische Zeitschrift, 67:123143.Google Scholar
Broili, F. 1926. Über Sclerocephalus haeuseri Goldfuss. Sitzungsberichte der Bayerischen Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Abteilung, 1926:199–122.CrossRefGoogle Scholar
Bystrow, A. P. 1938. Dvinosaurus als neotenische form der stegocephalen. Acta Zoologica, 19:209295.Google Scholar
Bystrow, A. P. and Efremov, J. A. 1940. Benthosuchus sushkini Efremov: A labyrinthodont from the Eotriassic of the Sharzhenga River. Trudy Paleontologicheskogo Instituta, 10, 152 p.Google Scholar
Cabrera, A. 1944. Sobre un estegocéfalo de la provincia de Mendoza. Notas Museo Universidad Nacional de La Plata IX, Paleontologia, 69:421429.Google Scholar
Carroll, R. L. 1964. Early evolution of the dissorophid amphibians. Bulletin of the Museum of Comparative Zoology, Harvard University, 131:161250.Google Scholar
Carroll, R. L. 1967. Labyrinthodonts from the Joggins Formation. Journal of Paleontology, 41:111142.Google Scholar
Case, E. C. 1911. Revision of the Amphibia and Pisces of the Permian of North America. Carnegie Institute of Washington Publication, 146, 179 p.Google Scholar
Case, E. C. 1915. The Permo-Carboniferous Red Beds of North America and their vertebrate fauna. Carnegie Institute of Washington Publication, 207, 148 p.Google Scholar
Case, E. C. 1922. New reptiles and stegocephalians from the Upper Triassic of western Texas. Carnegie Institute of Washington Publication, 321, 84 p.Google Scholar
Case, E. C. 1935. Description of a collection of associated skeletons of Trimerorhachis . Contributions from the Museum of Paleontology, University of Michigan, 4:227274.Google Scholar
Chase, J. N. 1965. Neldasaurus wrightae, a new rhachitomous labyrinthodont from the Texas Lower Permian. Bulletin of the Museum of Comparative Zoology, Harvard University, 133:155225.Google Scholar
Chernin, S. 1977. A new brachyopid, Batrachosuchus concordi sp nov. from the Upper Luangwa Valley, Zambia with a redescription of Batrachosuchus browni Broom, 1903. Palaeontologia Africana, 20:87109.Google Scholar
Clack, J. A. 2002. Gaining Ground: The Origin and Evolution of Tetrapods. Indiana University Press, Bloomington, 369 p.Google Scholar
Clack, J. A. and Coates, M. I. 1995. Acanthostega gunnari, a primitive, aquatic tetrapod? Bulletin du Muséum National d'Histoire Naturelle, Paris, 4ème Série, 17:359372.Google Scholar
Clack, J. A. and Finney, S. M. 2005. Pederpes finneyae, an articulated tetrapod from the Tournaisian of Western Scotland. Zoological of Systematic Palaeontology, 2:311346.CrossRefGoogle Scholar
Coates, M. I. 1996. The Devonian tetrapod Acanthostega gunnari Jarvik: Postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution. Transactions of the Royal Society of Edinburgh: Earth Sciences, 87:363421.Google Scholar
Coates, M. I. and Clack, J. A. 1990. Polydactyly in the earliest known tetrapod limbs. Nature, 347:6669.Google Scholar
Coates, M. I. and Clack, J. A. 1991. Fish-like gills and breathing in the earliest known tetrapod. Nature, 352:234236.Google Scholar
Colbert, E. H. 1955. Scales in the Permian amphibian Trimerorhachis . American Museum Novitates, 1740, 17 p.Google Scholar
Coldiron, R. W. 1978. Acroplous vorax Hotton (Amphibia, Saurerpetontidae) restudied in the light of new material. American Museum Novitates, 2662, 27 p.Google Scholar
Cope, E. D. 1877. Descriptions of extinct vertebrata from the Permian and Triassic Formations of the United States. Proceedings of the American Philosophical Society, 17:182195.Google Scholar
Cope, E. D. 1878. Descriptions of extinct Batrachia and Reptilia from the Permian Formation of Texas. Proceedings of the American Philosophical Society, 17:505530.Google Scholar
Cope, E. D. 1882. Third contribution to the history of the Vertebrata of the Permian Formation of Texas. Proceedings of the American Philosophical Society, 20:405461.Google Scholar
Cope, E. D. 1884. The Batrachia of the Permian period of North America. The American Naturalist, 18:2639.CrossRefGoogle Scholar
Cope, E. D. 1895. A batrachian armadillo. The American Naturalist, 29:998.Google Scholar
Cope, E. D. 1896. The reptilian order Cotylosauria. Proceedings of the American Philosophical Society, 36:436457.Google Scholar
Cope, E. D. and Matthew, W. D. 1915. Hitherto Unpublished Plates of Tertiary Mammalia and Permian Vertebrata. American Museum of Natural History, Washington, DC, 300 p.Google Scholar
Dalquest, W. W. and Mamay, S. H. 1963. A remarkable concentration of Permian amphibian remains in Haskell County, Texas. Journal of Geology, 71:641644.Google Scholar
Daly, E. 1994. The Amphibamidae (Amphibia: Temnospondyli), with a description of a new genus from the Upper Pennsylvanian of Kansas. University of Kansas, Museum of Natural History Miscellaneous Publication, 85, 59 p.Google Scholar
Damiani, R. J. 2001. A systematic revision and phylogenetic analysis of Triassic mastodonsauroids (Temnospondyli: Stereospondyli). Zoological Journal of the Linnean Society, 133:379482.Google Scholar
Damiani, R. J. 2003. A new brachyopid temnospondyl from the Cynognathus Assemblage Zone, Upper Beaufort Group, South Africa. Journal of Vertebrate Paleontology, 23:6778.Google Scholar
Dutuit, J. M. 1976. Introduction à l'étude paléontoloique du Trias continental Marocain. Description des premiers stégocephales recueillis dans le couloir d'Argana (Atlas Occidental). Mémoires du Muséum National d'Histoire Naturelle, Paris, 36, 253 p.Google Scholar
Efremov, J. A. 1937. On stratigraphic subdivision of the continental Permian and Triassic of the U.S.S.R. on the basis of the fauna of early Tetrapods. Comptes Rendus de l'Académie des Sciences de l'URSS, 16:121126.Google Scholar
Foreman, B. C. 1990. A revision of the cranial morphology of the Lower Permian temnospondyl amphibian Acroplous vorax Hotton. Journal of Vertebrate Paleontology, 10:390397.Google Scholar
Fritsch, A. 1877. Ueber einen neuen Saurier aus den kalksteinen der Permformation (U.Dyas) aus Braunau in Böhen. Verlag der könglich-böhmischen Gesellschaft der Wissenschaften, 1877, 3 p.Google Scholar
Godfrey, S. J. 1989. The postcranial skeletal anatomy of the Carboniferous tetrapod Greererpeton burkemorani Romer, 1969. Philosophical Transactions of the Royal Society of London B, 323:75133.Google Scholar
Godfrey, S. J. and Reisz, R. R. 1991. The vertebral morphology of Gephyrostegus bohemicus Jaekel 1902, with comments on the atlas-axis complex in primitive tetrapods. Historical Biology, 5:2736.Google Scholar
Goldfuss, G. A. 1847. Beiträge zur Vorweltlichen Fauna des Steinkohlegebirges. Verhandlungen des naturhistorischen Vereins für rheinlande und Westphalen, 27 p.Google Scholar
Gubin, Y. M. 2004. A new dvinosaur (Amphibia, Temnospondyli) from the Upper Tatarian of the Midddle Volga Region. Paleontological Journal, 38:190199.Google Scholar
Haines, R. W. 1934. The primitive form of epiphysis in the long bones of tetrapods. Journal of Anatomy, 72:323343.Google Scholar
Haines, R. W. 1969. Epiphyses and sesamoids, p. 81115. In Bellairs, A. d. A. and Parsons, T. S. (eds.), Morphology A. Volume 1. Academic Press, London and New York.Google Scholar
Hentz, T. F. and Brown, L. F. 1987. Wichita Falls-Lawton Sheet, Geologic Atlas of Texas. Bureau of Economic Geology, University of Texas, Austin.Google Scholar
Holmes, R. B. 1989. The skull and axial skeleton of the Lower Permian anthracosauroid amphibian Archeria crassidisca Cope. Palaeontographica Abteilung A- Palaozoologie-Stratigraphie, 207:161206.Google Scholar
Holmes, R. B., Carroll, R. L., and Reisz, R. R. 1998. The first articulated skeleton of Dendrerpeton acadianum (Temnospondyli, Dendrerpetontidae) from the Lower Pennsylvanian locality of Joggins Nova Scotia, and a review of its relationships. Journal of Vertebrate Paleontology, 18:6479.CrossRefGoogle Scholar
Hook, R. W. and Baird, D. 1984. Ichthycanthus platypus Cope, 1877, re-identified as the dissorophoid amphibian Amphibamus lyelli . Journal of Paleontology, 58:697702.Google Scholar
Hotton, N. 1959. Acroplous vorax, a new and unusual labyrinthodont from the Kansas Permian. Journal of Paleontology, 33:161178.Google Scholar
Howie, A. A. 1970. A new capitosaurid labyrinthodont from East Africa. Palaeontology, 13:210253.Google Scholar
Hunt, A. P. 1993. Revision of the Metoposauridae (Amphibia: Temnospondyli) and a description of a new genus from western North America. Museum of Northern Arizona Bulletin, 59:6797.Google Scholar
Jaeger, G. F. 1828. Über die Fossile Reptilien, Welche in Württemberg Aufgefunden Worden Sind. J. B. Metzer, Stuttgart, 48 p.Google Scholar
Jaekel, O. 1902. Ueber einen neuen paläozoischen Tetrapodentypus: Gephyrostegus bohemicus n. g. n. sp. Zeitschrift der Deutschen Geologischen Gesellschaft, 54:127132.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. Meddelelser om Grønland, 114, 90 p.Google Scholar
Lohmann, U. and Sachs, S. 2001. Observations on the postcranial morphology, ontogeny and palaeobiology of Sclerocephalus haeuseri (Amphibia: Actinodontidae) from the Lower Permian of Southwest Germany. Memoirs of the Queensland Museum, 46:771781.Google Scholar
Lombard, R. E. and Bolt, J. R. 1988. Evolution of the stapes in Paleozoic tetrapods: Conservative and radical hypotheses, p. 3767. In Fritzsch, B. (ed.), The Evolution of the Amphibian Auditory System. John Wiley and Sons, Chichester.Google Scholar
Long, J. A. and Gordon, M. S. 2004. The greatest step in vertebrate history: A paleobiological review of the fish-tetrapod transition. Physiological and Biochemical Zoology, 77:700719.CrossRefGoogle ScholarPubMed
Marsicano, C. A. 1993. Postcranial skeleton of a brachyopoid (Amphibia, Temnospondyli) from the Triassic of Mendoza (Argentina). Alcheringa, 17:185197.Google Scholar
Mcnamara, K. J. 1986. A guide to the nomenclature of heterochrony. Journal of Paleontology, 60:413.CrossRefGoogle Scholar
Mcnamara, K. J. 1988. The abundance of heterochrony in the fossil record, p. 287325. In McKinney, M. L. (ed.), Heterochrony in Evolution: A Multidisciplinary Approach. Plenum Press, New York.Google Scholar
Meckert, D. 1993. The pectoral girdle of Sclerocephalus haeuseri Goldfuss, 1847 in comparison with Eryops Cope, 1877 (Eryopoida, Amphibia, Permian). Palaeontographica Abteilung A- Palaozoologie-Stratigraphie, 229:113140.Google Scholar
Meyer, H. 1857. Reptilien aus der Steinkohlen-Formation in Deutschland. Palaeontographica, 6:59218.Google Scholar
Milner, A. R. and Sequeira, S. E. K. 1994. The temnospondyl amphibians from the Viséan of East Kirkton, West Lothian, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, 84:331361.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, 428:110.Google Scholar
Nielsen, E. 1954. Tupilakosaurus heilmani n. g. et n. sp. an interesting batrachomorph from the Triassic of East Greenland. Meddelelser om Grønland, 72:133.Google Scholar
Nikitin, V. B. 1995. Morphology of the postcranial skeleton of Dvinosaurus (Amphibia, Temnospondyli). 1. The structural diversity of the anterior limbs. Paleontological Journal, 29:96106.Google Scholar
Nikitin, V. B. 1997. On the structure of the postcranial skeleton in Dvinosaurus (Amphibia, Temnospondyli). 2, Scapulocoracoid. Paleontological Journal, 31:546551.Google Scholar
Nilsson, T. 1944. On the morphology of the lower jaw of Stegocephalia with special reference to Eotriassic stegocephalians from Spitsbergen. II General part. Kungliga Svenska Vetenskapsakademiens Handlingar, 21, 70 p.Google Scholar
Olsen, R. 1951. Size relations in the limb bones of Buettneria . Journal of Paleontology, 25:520524.Google Scholar
Olson, E. C. 1941. The family Trematopsidae. Journal of Geology, 49:149176.Google Scholar
Olson, E. C. 1956. Fauna of the Vale and Choza: 10. Trimerorhachis: Including a revision of pre-Vale species. Fieldiana: Geology, 10:225274.Google Scholar
Olson, E. C. 1979. Aspects of the biology of Trimerorhachis (Amphibia: Temnospondyli). Journal of Paleontology, 53:117.Google Scholar
Olson, E. C. and Lammers, G. E. 1976. A new brachyopoid amphibian, p. 4557. In Churcher, C. S. (ed.), Athlon: Essays in Palaeontology in Honour of Loris Shano Russell. Miscellaneous Publication of the Royal Ontario Museum, Toronto.Google Scholar
Olson, E. C. and Vaughn, P. P. 1970. The changes of terrestrial vertebrates and climates during the Permian of North America. Forma et Functio, 3:113138.Google Scholar
Owen, R. 1853. Notes on the above-described fossil remains. Quarterly Journal of the Geological Society of London, 9:6667.Google Scholar
Parrish, W. C. 1978. Paleoenvironmental analysis of a Lower Permian bonebed and adjacent sediments, Wichita County, Texas. Palaeogeography, Palaeoclimatology, Palaeoecology, 24:209237.Google Scholar
Pawley, K. and Warren, A. A. 2004. Immaturity vs. paedomorphism: A rhinesuchid stereospondyl postcranium from the Upper Permian of South Africa. Palaeontologia Africana, 40:110.Google Scholar
Pawley, K. and Warren, A. A. 2005. A terrestrial stereospondyl from the Lower Triassic of South Africa: The postcranial skeleton of Lydekkerina huxleyi (Amphibia: Temnospondyli). Palaeontology, 48:281298.Google Scholar
Pawley, K. and Warren, A. A. 2006. The appendicular skeleton of Eryops megacephalus (Temnospondyli: Eryopoidea) from the Lower Permian of North America. Journal of Paleontology, 80:561580.Google Scholar
Romer, A. S. 1922. The locomotor apparatus of certain primitive and mammal-like reptiles. Bulletin of the American Museum of Natural History, 46:517606.Google Scholar
Romer, A. S. 1928. Vertebrate faunal horizons in the Texas Permo-Carboniferous red beds. University of Texas Bulletin, Contributions to Geology, 2801:67108.Google Scholar
Romer, A. S. 1935. Early history of the Texas redbeds vertebrates. Bulletin of the Geological Society of America, 46:15971658.Google Scholar
Romer, A. S. 1969. A temnospondylous labyrinthodont from the Lower Carboniferous. Kirtlandia, 6, 20 p.Google Scholar
Romer, A. S. 1974. The stratigraphy of the Permian Wichita redbeds of Texas. Breviora, 427, 31 p.Google Scholar
Romer, A. S. and Price, L. W. 1940. Review of the Pelycosauria. Waverly Press, Baltimore, Maryland, 28, 538 p.Google Scholar
Ruta, M., Coates, M. I., and Quicke, D. L. J. 2003. Early tetrapod relationships revisited. Biological Reviews of the Cambridge Philosophical Society, 78:251345.Google Scholar
Sander, P. M. 1987. Taphonomy of the Lower Permian Geraldine bonebed in Archer County, Texas. Palaeogeography, Palaeoclimatology, Palaeoecology, 61:221236.Google Scholar
Sander, P. M. 1989. Early Permian depositional environments and pond bonebeds in central Archer County, Texas. Palaeogeography, Palaeoclimatology, Palaeoecology, 69:121.Google Scholar
Schoch, R. R. 1995. Heterochrony and the development of the amphibian head, p. 107124. In McNamara, K. J. (ed.), Evolutionary Change and Heterochrony. John Wiley and Sons, Chichester.Google Scholar
Schoch, R. R. 1999a. Comparative osteology of Mastodonsaurus giganteus (Jaeger, 1828) from the Middle Triassic (Lettenkeuper: Longobardian) of Germany (Baden-Württemberg, Bayern, Thüringen). Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie), 278, 175 p.Google Scholar
Schoch, R. R. 1999b. Studies on braincases of early tetrapods: structure, morphological diversity and phylogeny: 1, Trimerorhachis and other primitive tetrapods. Nues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 213:233259.Google Scholar
Schoch, R. R. 2002. The evolution of metamorphosis in temnospondyls. Lethaia, 35:309327.Google Scholar
Schoch, R. R. 2003. Early larval ontogeny of the Permo-Carboniferous temnospondyl Sclerocephalus . Palaeontology, 46:10551072.Google Scholar
Schoch, R. R. and Milner, A. R. 2004. Structure and implications of theories on the origin of lissamphibians, p. 345377. In Arriata, G., Wilson, M. V. H., and Cloutier, R. (eds.), Recent Advances in the Origin and Early Radiation of Vertebrates: Honoring Hans-Peter Schultze. Verlag Dr. Friedrich Pfiel, München.Google Scholar
Sengupta, D. P. 1995. Chigutisaurid temnospondyls from the Late Triassic of India and a review of the family Chigutisauridae. Palaeontology, 38:313339.Google Scholar
Sequeira, S. E. K. 1998. The cranial morphology and taxonomy of the saurerpetontid Isodectes obtusus comb. nov. (Amphibia: Temnospondyli) from the Lower Permian of Texas. Zoological Journal of the Linnean Society, 122:237259.Google Scholar
Shishkin, M. A. 1961. New data on Tupilakosaurus . Doklady of the Academy of Sciences of the U.S.S.R., 136:938941.Google Scholar
Shishkin, M. A. 1973. The morphology of the early amphibia and some problems of the lower tetrapod evolution. Trudy Paleontologicheskogo Instituta, 137, 257 p.Google Scholar
Shishkin, M. A. 2000. Evolution of the cervical vertebrae in temnospondyl amphibians and differentiation of the early tetrapods. Paleontological Journal, 34:534546.Google Scholar
Steyer, J.-S. 2000. Ontogeny and phylogeny in temnospondyls: A new method of analysis. Zoological Journal of the Linnean Society, 130:449467.Google Scholar
Steyer, J.-S., Laurin, M., Castenet, J., and De Ricqlès, A. 2004. First histological and skeletochronological data on temnospondyl growth: Palaeoecological and palaeoclimatological implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 206:193201.Google Scholar
Sushkin, P. P. 1936. Notes on the pre-Jurassic Tetrapoda from USSR III. Dvinosaurus Amalitzki, a perennibranchiate stegocephalian from the Upper Permian of north Dvina. Trudy Paleontologicheskogo Instituta, 5:4391.Google Scholar
Van Hoepen, E. C. N. 1911. Korte voorlopige beschrijving van te Senekal gevonden stegocephalen. Annals of the Transvaal Museum, 3:102106.Google Scholar
Voorhies, M. R. 1969. Taphonomy and population dynamics of an early Pliocene vertebrate fauna, Knox County, Nebraska. Contributions to Geology, University of Wyoming Special Paper, 1:169.Google Scholar
Warren, A. A. 1998. Karoo tupilakosaurid: A relict from Gondwana. Transactions of the Royal Society of Edinburgh: Earth Sciences, 89:145160.Google Scholar
Warren, A. A. and Hutchinson, M. N. 1983. The last labyrinthodont? A new brachyopoid (Amphibia, Temnospondyli) from the Early Jurassic Evergreen Formation of Queensland, Australia. Philosophical Transactions of the Royal Society of London B, 303, 62 p.Google Scholar
Warren, A. A. and Marsicano, C. A. 2000. A phylogeny of the Brachyopoidea (Temnospondyli, Stereospondyli). Journal of Vertebrate Paleontology, 20:462483.Google Scholar
Warren, A. A. and Ptasznik, R. 2002. The earliest fractured tetrapod bone. Alcheringa, 26:459463.Google Scholar
Warren, A. A. and Turner, S. 2004. The first stem tetrapod from the Lower Carboniferous of Gondwana. Palaeontology, 47:151184.Google Scholar
Warren, A. A., Rich, T. H., and Vickers-Rich, P. 1997. The last last labyrinthodonts? Palaeontographica Abteilung A- Palaozoologie-Stratigraphie, 247, 24 p.Google Scholar
Watson, D. M. S. 1919. The structure, evolution and origin of the Amphibia. The ‘orders’ Rachitomi and Stereospondyli. Philosophical Transactions of the Royal Society of London B, 209, 73 p.Google Scholar
Watson, D. M. S. 1956. The brachyopid labyrinthodonts. Bulletin of the British Museum of Natural History (Geology), 2:317392.Google Scholar
Werneburg, R. 1992. Sclerocephalus jogischneideri n. sp. (Eryopoidea, Amphibia) aus dem Unterrotliegenden (Unterperm) des Thuringer Waldes. Freiberger Forshungshefte, Palaontologie, 445:2948.Google Scholar
Williston, S. W. 1910a. Cacops, Desmospondylus; new genera of Permian vertebrates. Bulletin of the Geological Society of America, 21:249284.Google Scholar
Williston, S. W. 1910b. Dissorophus Cope. Journal of Geology, 18:526536.CrossRefGoogle Scholar
Williston, S. W. 1915. Trimerorhachis, a Permian temnospondyl amphibian. Journal of Geology, 23:246255.Google Scholar
Williston, S. W. 1916. The skeleton of Trimerorhachis . Journal of Geology, 24:291297.Google Scholar
Yates, A. M. and Warren, A. A. 2000. The phylogeny of the ‘higher’ temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of the Stereospondyli. Zoological Journal of the Linnean Society, 128:77121.Google Scholar
Zittel, K. A. 1888. Handbuch der Palæontologie. Abteilung 1. Palæozoologie Band III. Vertebrata (Pisces, Amphibia, Reptilia, Aves). München, Oldenbourg, 900 p.Google Scholar