Australian Paleogene vegetation and environments: evidence for palaeo-Gondwanan elements In the fossil records of Lauraceae and Proteaceae

Tropical rainforests in the northeast of Australia have been interpreted as being either communities largely comprising taxa that ‘invaded’ newly available environments from Sundaland during and after the Middle Miocene collision of the Australian plate and the Sunda plate, or refugia for humid-mesothermal Gondwanan taxa. Recent biogeographic analyses have suggested four ‘tracks’ (areas of endemism) that potentially account for some previously hypothesised floristic ‘elements’ defined by ‘tropical’ or Malesian origins. Early Cenozoic (Paleogene) macrofloral records of Lauraceae and Proteaceae are informative on these issues. Unequivocal macrofossil evidence for Lauraceae and Proteaceae occurs at least from the Early Paleocene (~ 65 million years, Ma) in Australia. This evidence appears contrary to the suggestion of their past dispersal from Malesia to the Australian plate. Tropical floristic ‘elements’ defined by Malesian origins are not appropriate for elucidating current biogeographic patterns of these families in Australia.