In this study, data from fossil macrofloras and microfloras in southeastern Australia are used to reconstruct vegetation and climates for the early Paleogene. Our data show that for much of the late Paleocene to middle Eocene, complex, species-rich forests were predominant in southeastern Australia, under mesothermal humid climates (mean annual temperature 16-22 °C, coldest quarter mean temperature > >10 °C, mean annual precipitation > >150 cm/yr). A minor cooling episode may have occurred in the mid-early Eocene. Megathermal climates may have been present in lowlands in the latest early Eocene, during the Cenozoic Global Climatic Optimum. These forests were dominated by taxa characteristic of present-day mesothermal-megathermal high-rainfall multistratal forests; e.g., Cunoniaceae, Elaeocarpaceae, Gymnostoma (Casuarinaceae), Lauraceae (e.g., Beilschmiedia, Cryptocarya and Endiandra), and Proteaceae. A prominent treefern element (Cyathea and Dicksonia types) was present in the early Eocene. A number of megathermal taxa, including Cupanieae (Sapindaceae) and Ilex (Aquifoliaceae), were present through the early and middle Eocene. Taxa characteristic of modern-day microthermal to mesothermal forests were also present, e.g., Nothofagus (Nothofagaceae), Eucryphia (Eucryphiaceae), Libocedrus (Cupressaceae) and Podocarpaceae (Acmopyle and Dacrycarpus). The relictual araucarian conifer, Wollemia, and other Araucariaceae were present through the late Paleocene to early Eocene. There is limited physiognomic evidence to suggest the late Paleocene to early Eocene forests contained some deciduous canopy trees.
The Lauraceae, with more than 2500 species in over 50 genera, and with the general lack of agreement in their recent classification, make an ideal canchdate for a global study based on leaf cuticles. A technique for preparing cuticles is presented, and three types of characters of use in such studies (cell form, slomatal complex, and special cell types) are discussed. Preliminary results demonstrate the utility of these cuticular characters in defining genera such as Endiandra and Beilschmiedia and in sorting out biogeograjihical anomalies, such as found in Caryodaphnopsis, wtiere the cuticles confirm placement of disjunct species within one genus. Potential challenges/problems posed by larger genera such as Litsea. Cryptocarya. Cinnamomum, Ocotea, and Nectandra are discussed.Two of the most recent classifications of the Lau-global generic revision of the Lauraceae, which folare those of Kostermans (1957) and Rohwer lows on from this project. Even in that study, the (Kubitzki et al., 1993). The former is based on his primary aim will be to place groups of species in own life-long studies, and the latter relies heavily consistently recognizable genera, and not necessaron Kostermans and on the w^ood anatomical studies ily to propose phylogenetic relationships (cladistic of Richter (1981), as well as including studies (pri-or otherwise). marily South American) by the author himself. The Cuticular studies of the Lauraceae are not novel, problems associated with these and other classifi-As early as 1926, Bandulska presented a study of cations of the Lauraceae are discussed by van der fossil and extant Lauraceae and described some Werff and Richter (1996, this issue). From that re-species of the former based on cuticular similarities view it is clear that further work is required to ar-to certain extant species. More recently. Hill (1986) rive at a satisfactory, or at least w idely acceptable, discussed those features of the cuticle that allowed classification of the family. Cuticular, and to a identification of Lauraceae, and placed the 12 spesmaller degree, leaf architectural studies form one cies of fossil Laurace found in the Eocene Nermodule in a multifaceted study of the generic de-riga deposit within the form genus Laurophyllum limitations of this family cuiTently in progress. based on these cuticular features. He made no at-The aim of this study is to analyze cuticular fea-tempt to place them relative to extant genera, tures for selected Lauraceae species whose generic Christophel and Rowett (in press) present descrippositions have been predetermined by others, and tions of leaf architecture and cuticles of all species in some cases questioned. At this time, no attempt of leafy Lauraceae found in Australia. They also has been made to use these features to confirm or present a dichotomous key to cuticular features that disprove the evolutionary position, or indeed the allows identification to the generic (or to a species **inonophyly" (sensu cladistics), of these groups of group within genus) level. Lauraceae....
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