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Setting up Pangaea: Triassic |
1 Natural History Museum, Department of Palaeontology, Cromwell Road, London SW7 5BD, UK (e-mail: M.Richter{at}nhm.ac.uk)
2 Universidade Estadual Paulista – UNESP/IGCE, CP 178, CEP 13506-900 Rio Claro, Brazil (e-mail: cetoledo{at}rc.unesp.br)
The Triassic fish faunas of the Southern Hemisphere are only known from a few sedimentary basins and the most productive sites are those from the Karoo Supergroup, in South Africa and the Sydney Basin of Australia. A single lungfish tooth plate ascribed to Ptychoceratodus cf. philippsi was recovered from Late Triassic (Carnian) red beds of southern Brazil and is described herein. This find extends to South America the palaeogeographic distribution of the genus, which occurs in the Early Triassic of Australia and South Africa and the Middle/Late Triassic of Europe and Late Triassic of Madagascar and India. The presence of this dipnoan solely in the uppermost part of the Santa Maria Formation suggests that the migration of Ptychoceratodus towards the Paraná Basin began not before the late Induan/early Olenekian (late Early Triassic). At that time, more humid (monsoonal) conditions prevailed in what is now southern Brazil, compared to semi-arid/desert conditions that dominated the Late Permian and possibly the earliest Early Triassic (the latter presumably not represented in the Paraná Basin).
