The Upper Permian articulate Phyllotheca australis from South Africa

Abstract

The taxonomic position of two fossil articulates, which form an important element of the Permian Gondwana flora, is examined in the light of recent collections from South Africa. Vegetative and fertile axes, dispersed and attached sporangia, in-situ spores, isolated and attached whorls of leaves, rhizomes bearing roots and branches, naked axes and a permineralized axis are all assigned to Phyllotheca australis. The large numbers of axes with attached sporangia allow a reinterpretation of the fertile structure and the specific diagnosis is emended. Although it is recognized that the fossils assigned to this taxon may represent a species complex, there exist no clear morphological discontinuities between the material previously assigned to P. australis and P. indica from widely separated Gondwanan localities. Phyllotheca australis was common throughout Gondwana, and is a reliable index fossil of the Upper Permian.