During the early 1990s I agreed to edit a book on the Cretaceous and Tertiary fossil plant record of Australia. A huge amount of information was available to be synthesised into a single volume, and I was fortunate to have an excellent group of people to draw on to produce a comprehensive set of chapters. Much of what they wrote has stood the test of time, and hence this reprint of that book should be a very welcome addition for anyone with an interest in the Australian fossil record. However, there have been some great advances in the last 25 years and it is important to recognise the contribution that has been made during that time to our understanding of the overall picture of the evolution of the living Australian vegetation. The best way to do this and to keep it up to date is via a website that provides details of important advances in this area over the last quarter of a century. The details of that website will be made available soon, and I invite everyone to submit relevant publications to that site.

It is an exciting time to be a palaeobotanist and the Australian fossil record promises much that is new and innovative for the future. I believe this reprint provides a very solid base that will stand for many years to come as the basis on which our reconstruction of past events can be made. The fossil record provides a vast and precious resource that demonstrates the history of life, and its relevance to our present and future well-being becomes more apparent as new approaches to using the fossil record as important tests of contemporary issues of great significance, like adaptation to climate change and determining the best approaches to fire management.

Studying the fossil record holds a strong appeal for young people and I hope this book and the associated web-based resources will attract more people to the plant fossil record of Australia, which stands as one of the great natural experiments in plant evolution.

This chapter reviews palynological evidence for the nature of the early Tertiary flora and vegetation of Australia. Because of difficulties in distinguishing between Late Oligocene and Early Miocene palynofloras, the interval of time covered is Paleocene to late Early Miocene, 65 to ca 18.5 million years (Ma) based on the geochronological time scale of Harland et al (1990).

The period is critical in tracing the origins and rise of the modern Australasian vegetation from an early, diverse angiosperm flora, such as that sampled in rift valley sequences along the southern margin of Australia during the Maastrichtian. Whether this flora was representative of inland regions or the northwest margins is debatable (see Twidale & Harris, 1977; Harris & Twidale, 1991), but it is clear that during the Danian a floristically more simple vegetation dominated by conifers and ferns prevailed in coastal/ lowland southern Australia. In most general terms, the subsequent history of the early Tertiary vegetation is the rise to prominence of floristically complex nonseasonal mesothermal-megathermal forest types and their timetransgressive replacement by more open or seasonal mesothermal -microthermal types during the Miocene. The same period saw the final separation of Australia from Antarctica, its northward drift through some 20 degrees of latitude and an irregular but overall decline in global high latitude sea surface temperatures of ca 13 °C from an Early Eocene maximum.

The last major reviews incorporating evidence for the early Tertiary vegetation (Barlow, 1981; Lange, 1982) concentrated upon individual elements within the flora, utilising cytogenetic, cladistic and other phylogenetic studies to augment but also to overcome deficiencies in the fossil database. Since these reviews, the substantial increase in the volume of published and unpublished information allows plant fossils to be used as primary evidence for the history of the early Tertiary flora and vegetation. Not surprisingly, this vegetation is found to have been as heterogeneous in space and labile in time as that of the Quaternary. Accordingly, this chapter concentrates on the fossil record per se, focussing on the sites and on the spore and pollen sequences that are available and what these imply, rather than adopting the broader approach of earlier reviews.

The preface to Pittock et al. (1978) discussed the question 'What is climate? (without saying so) and refers to its main feature - its variability. And this was in relation to modern climate! How difficult then to address the question of palaeoclimate. We must recognise and accept that any reconstruction of palaeoclimate is at best an approximation, and, even then, is averaged over time scales of hundreds of thousands to millions of years, a length in which modern 'short term5 variability is not decipherable. Many of the elements measured as part of modern climate are not recognisable in the geological record or must be implied from various features of the record. Although this may seem a somewhat negative way to introduce the subject, there are several firm conclusions that can be made about past climates and the way in which they have changed.

The purposes of this chapter are:

1. 1. To review the climate of Australia over the last 144 million years (Ma) (Cretaceous to Recent).

2. 2. To provide a background for other studies of Australian fauna and flora over the same interval.

3. 3. To stimulate discussion on the directions for further research into the Cretaceous- Cenozoic of Australia.

The figure of 144 million years is taken because that is what is understood to be the age of the boundary between the Jurassic and Cretaceous periods. It is based on our understanding of that boundary dated by isotopic methods and using constants that are accepted at present. It is not an absolute date and can be expected to vary as our understanding of the isotopic dating method improves. This range of time is taken because it is the one during which Australia underwent its major change from part of a supercontinent (Gondwana), to an isolated interval in which the modern fauna and flora evolved, to another when it is colliding with Asia and also undergoing changes associated with the influence of humanity.