Temnospondyli

Reconstruction of Dendrerpeton, from here.

Belongs within: Neostegalia.
Contains: Stereospondylomorpha, Dissorophoidea.

The Temnospondyli were one of the most significant early clades of amphibian-grade tetrapods, being recorded from the early Carboniferous (Visean) to the mid-Cretaceous (Albian). Whether they survived after this date depends on whether the modern amphibians (particularly frogs and salamanders) are accepted as derived temnospondyls. The clade as a whole is characterised by the presence of interpterygoid vacuities at least half as wide as the skull and bordered by triradiate pterygoids (Ruta et al. 2003). The majority of temnospondyls were semiaquatic, though the clade as a whole includes members varying from almost entirely terrestrial to fully aquatic.

Early Carboniferous temnospondyls include the Scottish Balanerpeton and the Nova Scotian Dendrerpeton, both medium-sized semi-terrestrial forms with the latter reaching about a metre in length. The Late Carboniferous and Early Permian Cochleosauridae were crocodile-like semi-aquatic ambush predators, reaching lengths of over 1.5 m. The Early Permian saw the appearance of even larger forms: Edops craigi reached about two metres in length whereas the three metre-long Eryops megacephalus was one of the largest land animals of its time. Eryops had a more strongly build appendicular skeleton than other temnospondyls, indicating a greater degree of adaptation for terrestrial locomotion. With the exceptions of Edops and the Cochleosauridae, most temnospondyls may be assigned to a clade Rhachitomi, basally characterised by vertebrae with a large intercentrum and smaller paired pleurocentra below the notochord.

Temnospondyli [Dvinosauria, Edopoidea, Euskelia, Limnarchia]
    |--Edops [Edopidae] DS20
    |    `--E. craigi Romer 1935 RCQ03
    `--+--Cochleosauridae SO05
       |    |--Procochleosaurus SO05
       |    `--+--Adamanterpeton ohioensis PSH17
       |       `--+--Cochleosaurus Fritsch 1885 DS20, D07
       |          |    |--C. bohemicus D07
       |          |    `--C. florensis Rieppel 1980 RCQ03
       |          `--Chenoprosopus SO05
       |               |--C. lewisi Hook 1993 RCQ03
       |               `--C. milleri Miehl 1913 M93
       `--Rhachitomi (see below for synonymy) PSH17
            |  i. s.: Peltobatrachus Panchen 1959 PSH17, D07 [Peltobatrachidae]
            |           `--P. pustulatus Panchen 1959 M93
            |--+--Parioxys M93 [Parioxyidae H00]
            |  |    |--P. bolli Carroll 1964 M93
            |  |    `--P. ferricolus Cope 1878 M93
            |  `--Eryopidae RCQ03
            |       |--Onchiodon labyrinthicus YW00, PSH17
            |       |--Eryops Miner 1925 DS20, D07
            |       |    |--E. avinoffi (Romer 1952) M93
            |       |    `--E. megacephalus Cope 1877 RCQ03
            |       `--Clamorosaurus M93
            |            |--C. borealis Gubin 1983 M93
            |            `--C. nocturnus Gubin 1983 M93
            `--+--Stereospondylomorpha DS20
               `--+--+--Palatinerpeton DS20
                  |  `--+--Iberospondylus schultzei DS20, PSH17
                  |     `--+--Dissorophoidea DS20
                  |        `--Lapillopsis [Lapillopsidae] PSH17
                  |             `--L. nanus Warren & Hutchinson 1990 PSH17, M93
                  `--+--Zatracheidae [Stegopidae] H00
                     |    |--Acanthostomatops vorax (Credner 1883) DS20, M93
                     |    |--Zatrachys serratus PSH17
                     |    |--Stegops newberryi (Cope 1875) H00, M93
                     |    `--Dasyceps H00
                     `--+--Capetus [Capetidae] DS20
                        |    `--C. palustris PSH17
                        `--+--Balanerpeton woodi Milner & Sequeira 1994 DS20, RCQ03
                           `--Dendrerpeton RCQ03 [Dendrerpetidae DS20]
                                |--D. acadianum Owen 1853 RCQ03
                                `--D. helogenes YW00

Rhachitomi [Astatodipnoa, Batrachii, Caducibranchia, Dipnoa, Eryopoidea, Lissamphibia, Paratoidia, Prosirenidae, Prosirenoidea] PSH17

*Type species of generic name indicated

REFERENCES

[DS20] Daza, J. D., E. L. Stanley, A. Bolet, A. M. Bauer, J. S. Arias, A. Čerňanský, J. J. Bevitt, P. Wagner & S. E. Evans. 2020. Enigmatic amphibians in mid-Cretaceous amber were chameleon-like ballistic feeders. Science 370: 687–691.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[H00] Holmes, R. 2000. Palaeozoic temnospondyls. In: Heatwole, H., & R. L. Carroll (eds) Amphibian Biology vol. 4. Palaeontology. The evolutionary history of amphibians pp. 1081–1120. Surrey Beatty & Sons.

[M93] Milner, A. R. 1993. Amphibian-grade Tetrapoda. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 665–679. Chapman & Hall: London.

[PSH17] Pardo, J. D., B. J. Small & A. K. Huttenlocker. 2017. Stem caecilian from the Triassic of Colorado sheds light on the origins of Lissamphibia. Proceedings of the National Academy of Sciences of the USA 114 (27): E5389–E5395.

[PS17] Pardo, J. D., M. Szostakiwskyj, P. E. Ahlberg & J. S. Anderson. 2017. Hidden morphological diversity among early tetrapods. Nature 546: 642–645.

[RCQ03] Ruta, M., M. I. Coates & D. L. J. Quicke. 2003. Early tetrapod relationships revisited. Biological Reviews 78: 251–345.

[SO05] Sidor, C. A., F. R. O’Keefe, R. Damiani, J. S. Steyer, R. M. H. Smith, H. C. E. Larsson, P. C. Sereno, O. Ide & A. Maga. 2005. Permian tetrapods from the Sahara show climate-controlled endmism in Pangaea. Nature 434: 886–889.

[YW00] Yates, A. M., & A. A. Warren. 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: 77–121.

Last updated: 29 January 2022.