Metoposaurid and mastodonsaurid stereospondyls from the Triassic – Jurassic boundary of Portugal

Abstract

Witzmann, F. & Gassner, T., March, 2008. Metoposaurid and mastodonsaurid stereospondyls from the Triassic – Jurassic boundary of Portugal. Alcheringa 32, 37–51. ISSN 0311-5518.

Remains of stereospondyl amphibians from the Triassic – Jurassic boundary of the Algarve, southern Portugal, are described for the first time. They consist of several intercentra of different sizes, ribs and fragments of the scapular girdle and the skull. The opisthocoelous morphology of some of the disc-like intercentra and the presence of a lateral flange on the clavicle indicate that parts of the material can be referred unambiguously to metoposaurid stereospondyls, representing the first evidence of this group from the Iberian Peninsula. Several other disc-like intercentra that are amphicoelous and thinner than those of the metoposaurids can be referred to mastodonsaurid stereospondyls (either Mastodonsaurus or Cyclotosaurus). The fossil locality is situated in a palaeorift system that linked the known metoposaurid localities in eastern North America, Morocco, and Central Europe.

Key words:

• Stereospondyli
• Metoposauridae
• Mastodonsauridae
• Iberian Peninsula
• Algarve
• Triassic – Jurassic boundary

Acknowledgements

We are grateful to Helmut Keupp and the late Bernard Krebs (IPFUB) who gave access to the Algarve material, and we also want to thank Rainer Schoch, Ross Damiani, Oliver Rauhut, Peter Witzmann, and Rodrigo Soler-Gijón for helpful comments. Many thanks to Stephen McLoughlin and two anonymous reviewers, whose reviews greatly improved the manuscript. Stefanie Klug and Carola Radke kindly prepared the photographs. Oliver Hampe (MB), Michael Ryan (CMNH), Charles Schaff (MCZ), and Rainer Schoch (SMNS) helped us to work on the collections in their care.