Pollen of proteaceous-type from latest Cretaceous sediments, southeastern Australia

Abundant and diverse proteaceous-like triaperturate pollen from Campanian-Maastrichtian sediments in the Otway Basin, southeastern Australia are systematically documented and compared with pollen of extant Proteaceae. Segregation of fossil and extant pollen types has been effected on apertural characters of which six states have been identified. Apertures are colpoid, poroid or porate. Pores of Propylipollis Martin & Harris, 1974 conform with those of subfamilies Grevillioideae and Carnarvonioideae. Colpoids of Beaupreaidites Cookson emend. Martin, 1973, poroids of Lewalanipollis gen. nov., and pores of Cranwellipollis Martin & Harris, 1974 are represented in subfamilies Proteoideae and Persoonioideae. Pores of Proteacidites Cookson ex Couper, 1953 occur in subfamilies Proteoideae and Sphalmioideae. In the Otway Basin fossil record, triporate apertures appear earlier than tricolpoids, triporoids and biporates; and diversity levels of proteaceous pollen are higher than reported from elsewhere implying the region may have been a diversification centre during Campanian and Maastrichtian times. Represented among the fossil pollen are types that conform with pollen of extant Proteaceae: Adenanthos, Beauprea, Beaupreopsis, and Stirlingia (subfamily Proteoideae); Persoonia (subfamily Persoonioideae); Carnarvonia (subfamily Carnarvonioideae); and Bleasdalia, Grevillea, Knightia, Macadamia and Telopea (subfamily Grevillioideae). The Late Cretaceous pollen record thereby implies the presence of sclerophyll and rainforest taxa in a vegetation which was composed of diverse podocarps (Dacrydium, Dacrycarpus, Lagarostrobos, Podocarpus, Microcachrys), araucarians, and a range of angiosperms (Nothofagus, Gunnera, Ilex, Ascarina, Callitriche, Trimeniaceae, Winteraceae, Ranunculaceae and possibly Epacridaceae). Thirty-one pollen species are described and referred to five genera, of which Lewalanipollis is new. New species include Lewalanipollis senectus, L. trycheros, Propylipollis areolatus, P. crotonoides, Proteacidites cooksoniae and Proteacidites variverrucatus

Community associations and structure in the Late Cretaceous vegetation of southeast Australasia and Antarctica

The structure and species richness of the Late Cretaceous (Santonian-Maastrichtian) vegetation in the Otway Basin, southeast Australia is reconstructed based on knowledge of palaeolatitudes, palaeotemperatures, plant taxa identified from fossil spores and pollen, and ecophysiological relationships established for present-day ecosystems. The vegetation, which grew at palaeolatitudes of 60-65°S and at mean annual palaeotemperatures of 16.5-19°C, comprised tall open-forests (Foliage Projective Cover 60-70%, height about 30 m) containing austral conifer and proteaceous taxa having coriaceous, notophyll-sized leaves. Today the taxa (Podocarpus, Dacrydium, Dacrycarpus, Knightia, Gevuina, Macadamia) from a minor component of upland closed-forests (usually termed rainforests) of tropical northeast Australia and New Caledonia. A conical-shaped crown to the trees of the tall open-forests situated in high latitudes during the Cretaceous would enable some light to penetrate the canopy to a shrubby understorey (of Proteaceae, Winteraceae, Trimeniaceae, Nothofagus, and Ilex) and a ground stratum of diverse cryptogams. On nutrient-poor, waterlogged sites fringing the forest, sclerophyllous leaved taxa (Adenanthos, Stirlingia, Epacridaceae, and possibly Beauprea) developed, with wetland swamps of Callitriche, ferns and some epacrids. In cooler localities in New Zealand and Antarctica, the productivity of the forests would have been greater, and the canopy taxa mainly with coriaceous, microphyll-sized leaves. Austral podocarps and Proteaceae occurred in the canopy of New Zealand forests, whereas the canopy of Antarctic forests contained podocarps and Nothofagus