Nature 373, 420 - 425 (02 February 1995); doi:10.1038/373420a0

Elginerpeton pancheni and the earliest tetrapod clade

Per E. Ahlberg

Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5BD, UK

THE first 'tetrapod-like' bones from the Scottish Upper Devonian site of Scat Craig (Scat Craig beds, Upper Frasnian) were figured and discussed in 1991 (ref. 1). Additional specimens have since been discovered that permit a formal description, and the background knowledge of Devonian tetrapod anatomy has greatly improved^2–7. These discoveries emphasize the uniqueness and phylogenetic importance of the Scat Craig material. Elginerpeton pancheni gen. et sp. nov., described here on the basis of cranial remains from Scat Craig, is, together with the fragmentary genus Obruchevichthys from the Upper Frasnian of Latvia and Russia^{1, 8, 9} , the oldest known stem tetrapod. Elginerpeton and Obruchevichthys form a clade that is the sister group of all other Tetrapoda. This contrasts with the later Devonian stem tetrapods, which all seem to represent separate plesions. Elginerpeton also has a unique, derived head morphology; it shows that the earliest phase of tetrapod evolution was accompanied by previously unrecognized morphological and phylogenetic diversification.

References

1.	Ahlberg, P. E. Nature 354, 298−301 (1991). | Article |
2.	Coates, M. I. & Clack, J. A. Nature 352, 234−235 (1991). | Article | ISI |
3.	Lebedev, O. A. & Clack, J. A. Palaeontology 36, 721−734 (1993).
4.	Clack, J. A. Meddr. Grønland Geoscience 31, 3−24 (1994).
5.	Clack, J. A. Nature 369, 392−394 (1994). | Article | ISI |
6.	Ahlberg, P. E., Lukevis, E. & Lebedev, O. Phil. Trans. R. Soc. B343, 303−328 (1994).
7.	Daeschler, E. B., Shubin, N. H., Thomson, K. S. T. & Amaral, W. W. Science 265, 639−642 (1994).
8.	Vorobyeva, E. I. Trudy paleont. Inst. 163, 1−239 (1977).
9.	Ahlberg, P. E. & Milner, A. R. Nature 368, 507−514 (1994). | Article | ISI |
10.	Gaffney, E. S. Bull. Carnegie Mus. nat. Hist. 13, 92−105 (1979).
11.	Panchen, A. L. & Smithson, T. R. Biol. Rev. 62, 341−438 (1987). | ISI |
12.	Godfrey, S. J. Phil. Trans. R. Soc. B323, 75−133 (1989).
13.	Campbell, K. S. W. & Bell, M. W. Alcheringa 1, 369−381 (1977).
14.	Jarvik, E. Basic Structure and Evolution of Vertebrates Vol. 1 (Academic, London, 1980).
15.	Miles, R. S. The Old Red Sandstone Antiarchs of Scotland: Family Bothriolepididae (Palaeontographical Society, London, 1968).
16.	Gross, W. Abh. dt. Akad. Wiss. Math.-naturw. Kl. 1, 3−130 (1950).
17.	Harland, W. B. et al. A Geologic Time Scale 1989 (Cambridge University Press, 1989).
18.	Coates, M. I. & Clack, J. A. Nature 347, 66−69 (1990). | Article | ISI |
19.	Coates, M. I. in Developmental Patternin of the Vertebrate Limb (eds Hinchliffe, J. R. et al.) 325−337 (Plenum, New York, 1991).
20.	Warren, J. W. & Wakefield, N. A. Nature 238, 469−470 (1972). | Article | ISI |
21.	Lebedev, O. A. Dokl. Akad. Nauk. SSSR 278, 1407−1473 (1984).
22.	Gross, W. Abh. preuss. Akad. Wiss. Math.-naturw. Kl. 1941, 1−51 (1941).