MACROFOSSIL CASUARINACEAE - THEIR IDENTIFICATION AND THE OLDEST MACROFOSSIL RECORD, GYMNOSTOMA-ANTIQUUM SP-NOV, FROM THE LATE PALEOCENE OF NEW-SOUTH-WALES, AUSTRALIA

The oldest known Casuarinaceae macrofossils, from late Paleocene sedim ents at Lake Bungarby in New South Wales, are assigned to a new specie s of Casuarinaceae, Gymnostoma antiquum. The nearest living relatives of this species are the Papua New Guinean Gymnostoma species and in pa rticular one as yet unnamed species. Previous problems relating to the preparation, identification and description of Casuarinaceae macrofos sils are examined and clarified. The ecology of both living Gymnostoma and G. antiquum are discussed. The decrease in catastrophic disturban ce and climate seasonality during the Cenozoic were probably major con tributing factors leading to the current distribution of Gymnostoma.