Pollen evidence for Late Cretaceous differentiation of Proteaceae in southern polar forests

Abstract

Amongst diverse and abundant fossil proteaceous pollen in southeastern Australian Late Cretaceous (Campanian–Maastrichtian) sediments are forms identical with pollen of extant taxa within subfamilies Proteoideae, Persoonioideae, Carnarvonioideae, and Grevilleoideae. Taxa identified now have disparate geographic ranges within Australasia. Sclerophyllous Adenanthos and Stirlingia (Proteoideae) are restricted to the southern Australian Mediterranean climatic region; Persoonia (Persoonioideae) ranges into higher rainfall areas of eastern and northern Australia. Grevillea exul – Grevillea robusta and Telopea (Grevilleoideae) and Carnarvonia (Carnarvonioideae) occur in or fringe rain forests in eastern Australasia, as do other members (Macadamia, Gevuina–Hicksbeachia, Knightia, and Beauprea) reported previously. Pollen evidence thereby confirms evolution of both rain forest and sclerophyll members by the Campanian–Maastrichtian. Turnover of proteaceous pollen taxa near the Cretaceous–Tertiary boundary may reflect contemporaneous modifications to the proteaceous communities. Associated with the Late Cretaceous Proteaceae were diverse conifers (Microcachrys, Lagarostrobus, Podocarpus, Dacrydium, Dacrycarpus, and Araucariaceae), Nothofagus, Ilex, Gunnera, Ascarina, Winteraceae, Trimeniaceae, and probable Epacridaceae. The vegetation, which fringed a narrow estuary separating Antarctica from southern Australia, implies a mosaic of rain forest and sclerophyll communities but has no modern analogue. Key words: Proteaceae, Late Cretaceous, Australia, Antarctica.

The macrofossil record of Proteaceae in Tasmania: a review with new species

“…The relevant genera, and possibly subgeneric groups, may have arisen in the Late Cretaceous or Early Tertiary (e.g. Johnson and Briggs 1975;Dettmann and Jarzen 1991) but the general drying of climates in southern Australia since the Miocene (Bowler 1982) probably prompted massive speciation in these groups. Thus Memon (1984) recorded a marked post-Pliocene increase in pollen surface types, attributed largely to Grevillea and Hakea, and most extant species occur in seasonally dry climates (e.g.…”

“…Palynomorphs of Proteaceae were particularly diverse, and dominated south-eastern Australian palynofloras in the Palaeocene and Eocene, with many taxa disappearing at about the end of the Eocene Macphail et al 1994). Dettmann and Jarzen (1991) used the pollen record to imply that many of the rainforest lineages, and at least some of the scleromorphic lineages, had differentiated by the Late Cretaceous. Their evidence is somewhat ambiguous because of long gaps in the fossil record of some taxa, leaving the possibility that the similarity of some fossil pollen to modern species may be due to convergence .…”

Valdivian ecosystems in the Late Cretaceous and Early Tertiary of Antarctica: further evidence from myrtaceous and eucryphiaceous fossil wood

“…Eucryphia has an extensive fossil record in southeastern Australia, with macrofossil evidence extending back to the Late Palaeocene (Hill, 1991;Taylor and Hill, 1996;Barnes et al, 2001). However, this pattern of earlier occurrence of austral groups in Antarctica than elsewhere in the Southern Hemisphere has been noted before with respect to other groups such as Lophosoriaceae (Dettmann, 1986;Cantrill, 1998), Nothofagaceae (Dettmann, 1989), Proteaceae (Askin, 1989;Dettmann and Jarzen, 1991), and with respect to genera within the Cunoniaceae such as Weinmannia, which occurs from the Late Cretaceous in Antarctica (e.g. Poole et al, 2000a;Cranwell, 1959), but does not appear until the Oligocene in Australia (see Barnes et al, 2001).…”

Biodiversity of Terrestrial Ecosystems in Tropical to Temperate Australia

“…The development of the Gondwanan vegetation in the Late Cretaceous through the Cainozoic-palynological studies initiated by Cookson in the University of Melbourne in the 1940s [13][14][15][16]-was traced by Martin in the University of New South Wales and by Dettmann in the University of Queensland [17][18][19][20][21][22][23][24][25][26][27][28][29]. Fossil pollen grains preserved in the brown coal deposits of the Early Tertiary reveal that the Gondwanan Antarctic beech, Nothofagus subsection brassii, today found in New Caledonia and New Guinea, was widely spread in southern Australia [14][15][16][19][20][21][22][23][24][25][26]; limited numbers of pollen grains of the temperate Nothofagus subsections fusca and menziesii were found in the same deposits.…”