Towards new paradigms in Permo-Triassic Karoo palaeobotany (and associated faunas) through the past 50 years
Anderson, Heidi Marguerite
Anderson, John Malcom
Bernard Price Institute for Palaeontological Research
Advances through the past 50 years (1945 to 1995) have shown, indisputably, that the Permo-Triassic Karoo flora (with associated insect faunas) is as important globally as is the famous tetrapod fauna. We justify this in regard to the three most productive horizons: the Middle Ecca (Early to Middle Permian), Estcourt Formation (Late Permian) and the Molteno Formation (Late Triassic). The Middle Ecca gained international prominence through the collections ofLe Roux from 1946 to 1955 and the publications of Plum stead from 1952 to 1962, which demonstrated for the first time a wide suite of fructifications found attached to Glossopteris leaves. Similar finds have subsequently been made throughout the rest of the Gondwana Permian. The Glossopteridales remain unique among fossil gymnosperm orders in yielding such a diverse range of articulated (organically attached) foliage/fruit material. The Estcourt Formation offers an unparalleled opportunity to study ecosystems of the Late Permian prior to the extinction event terminating the period. The formation is singular in that it yields an excellent, well known flora and insect fauna (sampled primarily by van Dijk from 1957 to 1984 and Benecke, Anderson and Anderson from 1969 to 1971) in conjunction with a diverse tetrapod fauna. The Molteno Formation provides a window onto Late Triassic plant and insect communities, at around the time of origin of the mammals, dinosaurs and birds, perhaps unrivalled elsewhere in the world. The extensive/intensive collections of the Molteno (made by Anderson and Anderson over nearly 30 years from 1967 to the present) allow the application of a statistical projection hinting at the extraordinary possibility of biodiversities akin to those of today. The gymnosperms ofthe Late Triassic may well have been as rich in species and orders as are the extant angiosperms (flowering plants).
Karoo, Permo-Triassic, megaflora, insects, tetrapods, biodiversity.