The Brandy Creek fossil flora Rachael Louise Keefe Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy November 2012 School of Engineering and Science Faculty of Health, Engineering and Science Declaration of authenticity “I, Rachael Louise Keefe declare that the PhD thesis entitled The Brandy Creek fossil flora is no more than 100,000 words in length including quotes and exclusive of tables, figures, appendices, bibliography, references and footnotes. This thesis contains no material that has been submitted previously, in whole or in part, for the award of any other academic degree or diploma. Except where otherwise indicated, this thesis is my own work”. Signature Date ii. Abstract A detailed quantitative study of the fossil flora, palaeoclimate and palaeoecology of the Eocene Brandy Creek fossil site, Bogong High Plains, Victoria, Australia was undertaken. Taxonomic assessment of Leaf macrofossils reveals 18 morphotypes that have affinity with nearest living relatives including Lauraceae genera Cryptocarya, Endiandra and Litsea and the families Cunoniaceae and Elaeocarpaceae. The pollen and spore record at Brandy Creek reveals 36 palynomorphs, with many of them having affinities with fossil and modern Dicksoniaceae, Araurcariaceae and Proteaceae and Nothofagus. The Palaeoclimate of the Brandy Creek flora was reconstructed using Leaf Margin Analysis and Bioclimatic Analysis giving a Mean Annual Temperature (MAT) of 19.7 °C and 18.7 °C respectively. The climate profile of Brandy Creek is indicative of mesothermal rainforests of north eastern Queensland today. Using both taxonomic information from leaf macrofossil and palynomorphs, combined with palaeoclimate data the Brandy Creek palaeoecology is reconstructed. The result show that the Brandy Creek flora is moderately diverse. The flora at Brandy Creek is representative of the flora that was present in south eastern Australia during the Eocene. The diversity of the Brandy Creek flora is comparable to the modern day forest of north eastern Queensland and is characteristic of simple notophyll – microphyll vine forest with an MAT between MAT of 15.7– 21.7°C and a MAP of 107 – 320cm/yr which is indicative of mesothermal conditions. iii Acknowledgements I am extremely grateful to my supervisors Dr David Greenwood and Dr Randall Robinson, for their commitment, advice, support, patience, and understanding during the course of my research. This project was financially supported by the Australian Research Council in the form of a research grant to Drs David Greenwood and John Webb: Stratigraphy and palaeoenvironments of Victorian Highland Tertiary macrofloras. I acknowledge the support of the Commonwealth Department of Education, Employment and Youth Affairs in the form of an Australian Postgraduate Award. I’d also like to thank Dr Anthony Vadala, Dr Mark Scarr, Dr David Steart and Dr Stephen McLouglin for their assistance with field work. I’d also like to thank Dr Stephen McLouglin and Dr John Webb for assisting in the development of a stratigraphic log of the Brandy Creek locality. I’d also like to thank Dr Alan Partridge and Dr Barbara Wagstaff for their assistance with the Brandy Creek palynology. I am grateful to the University of Melbourne Botany Department for providing to me access to the scanning electron microscope which assisted greatly in the identification of leaf cuticle characters, and to the Museum Victoria for housing the Brandy Creek fossil flora collection. I’d also like to thank my work colleagues at Victoria University, especially Gary Carter, Laurie Farrugia, Allan Davidson and Jillian Bambach for their continued support, patience, and understanding over the protracted period. I am especially grateful to my parents, Denise and Eric and my sister Lisa as well as my extended family who have sustained their support over the years. I like to give a special thank you to my closest friend Megan, who has supported me both emotionally and practically over the years. My biggest thankyou is to my partner Scott and my two beautiful children Sarah and William whose support, encouragement and understanding and particularly patience gave me the strength to finish this project. iv. Table of Contents. Declaration of authenticity ii Abstract iii Acknowledgements iv List of Tables v List of Figures v 1. Introduction 1 2. Leaf macrofossils of the Brandy Creek Eocene Locality, Bogong High Plains, 9 Victoria 2.1. Introduction 9 2.2. The use of leaf and cuticular morphology in the identification of leaf 11 macrofossils 2.2.1. Leaf architecture 11 2.2.2. Leaf cuticle 11 2.2.3. Lauraceae Jussieu 13 2.2.4. Cunoniaceae R.Br and Elaeocarpaceae Juss 16 2.3. Materials and methods 17 2.3.1. Locality description 17 2.3.2. Site sampling 18 2.3.3. Fossil preparation 18 2.3.4. Taxonomic analysis 20 2.4. Results 21 2.4.1. Cluster analysis of Brandy Creek morphotypes 21 2.4.2. Taxonomic descriptions of the Brandy Creek macroflora 24 2.5. Discussion 33 2.5.1. Lauraceae 33 2.5.2. Cunoniacae/Elaeocarpaceae 35 2.5.3. Modern counterparts of the Brady Creek flora 37 2.6. Conclusions 39 2.7. References 39 3. The Brandy Creek Microflora (Spores and Pollen). 85 3.1. Introduction 85 3.1.1. The value of pollen and spores (palynology). 85 3.1.2. Limitations with the fossil pollen and spore record. 87 3.2. Methods and Materials 89 3.2.1. Fossil sampling on site 89 3.2.2. Extraction of pollen and spores 90 3.2.3. Taxonomic analysis of the palynological samples 90 3.2.4. Floristic composition 90 3.3. Results 91 3.4. Discussion 92 3.4.1. The Brandy Creek Pteridophytes 92 3.4.2. Brandy Creek Gymnosperms 93 3.4.3. The Brandy Creek Angiosperms 94 3.4.4. The Eocene Southern Hemisphere Flora 96 3.4.5. Modern counterparts of the Brandy Creek pollen and spore flora 98 3.5. Conclusions 100 3.6. References 100 4. Palaeoclimate reconstruction of the Brandy Creek Eocene locality, Bogong 113 High Plains, Victoria 4.1. Introduction 113 4.1.1. Palaeoclimate during the Eocene 114 4.1.2. Palaeoclimate reconstruction through palaeobotanical proxies 117 4.2. Materials and Methods 124 4.3. Results 125 4.3.1. Leaf margin analysis 125 4.3.2. Bioclimatic analysis 126 4.3.3. Epiphyllous Fungi 127 4.4. Discussion 127 4.5. Conclusions 130 4.6. References 131 5. Palaeoecological reconstruction of the Brandy Creek Eocene locality, Bogong 148 High Plains, Victoria. 5.1. Introduction 148 5.1.1. Australia during the Eocene 148 5.1.2. Australian Eocene Climates and Vegetation 150 5.1.3. Reconstructing Ancient Plant Communities 152 5.2. Materials and Methods 154 5.3. Results 159 5.3.1. Overview of the Brandy Creek Fossil Flora 159 5.3.2. Trends in Diversity and Plant Community Composition 161 5.4. Discussion 166 5.4.1. Brandy Creek during the Eocene 166 5.4.2. Eocene Regional Diversity 168 5.4.3. Brandy Creek vs. modern flora 169 5.5. Conclusion 170 5.6. References 171 6. Conclusions 201 6.1. Major findings of the study 201 6.2. Further work 202 6.3. References 203 Appendix 1 Publication and manuscript 204 Appendix 2 Leaf morphotypes scores 205 Appendix 3 Leaf margin scores 206 Appendix 4 Climate profiles 207 List of Tables Table 2.1. List of the 79 cuticular characters used to group cuticle 49 specimens in this study Table 2.2. Main characters used to distinguish between morphotypes at 50 Brandy Creek Table 3.1. Fossil and spore species (palynomorphs) list for Brandy Creek 107 Table 3.2. Comparison of pollen and spore count for Brandy Creek and 108 other early to late Eocene localities in south eastern Australia Table 4.1. Leaf margin equations for Australia and Global calibrations. 141 Table 4.2. Nearest living relatives of Brandy Creek and other Eocene 142 flora. M= leaf macrofossils and P =pollen/spores. Table 4.3. Key for identification of Fungal Germlings 143 Table 4.4. Leaf Margin Analysis and Bioclimatic climate estimates for 144 south eastern Australian Eocene Floras. Table 4.5. Comparison between Brandy Creek and other Eocene LMA 144 estimates. Table 4.6. Palaeoclimate estimates based on bioclimatic analysis of south 145 eastern Australian Eocene Floras. Table 4.7. Percentage of each grade of epiphyllous fungi found at Brandy 146 Creek. Table 5.1. List of Brandy Creek leaf morphotypes 182 Table 5.2. Percentage count of pollen and spores at Brandy Creek 183 Table 5.3. Comparison of pollen and spore counts for Brandy Creek and 184 other Eocene localities in south eastern Australia Table 5.4. Fossil palynomorphs at Brandy Creek individual samples 185 . List of Figures Fig. 2.1 Map of Australia showing the location of macroflora’s 51 and microflora’s discussed in the text Fig. 2.2. Stratigraphic log of the Brandy Creek outcrop 52 Fig. 2.3. Brandy Creek outcrop showing laminated siltstone and 53 sandstone containing fossil plant material Fig. 2.4. Dendogram showing the relationship between 54 morphotypes at Brandy Creek Fig. 2.5. Floristic composition of Brandy Creek and other Eocene 55 localities in south eastern Australia Fig. 2.6 – 2.10. Brandy Creek 001 Lauraceae aff. Cyptocarya 56 v Fig. 2.11. Brandy Creek 002 Lauraceae aff. Cryptocarya 56 Fig. 2.12 – 2.15. Brandy Creek 002 Lauraceae aff. Cryptocarya 58 Fig. 2.16 – 2.17. Brandy Creek 003 Lauraceae aff. Cryptocarya 58 Fig. 2.18 – 2.19. Brandy Creek 003 Lauraceae aff. Cyptocarya 60 Fig. 2.20 - 2.23. Brandy Creek 009 Lauraceae aff. Cyptocarya 60 Fig. 2.24. Brandy Creek 009 Lauraceae aff. Cyptocarya 63 Fig. 2.25 – 2.29. Brandy Creek 015 Lauraceae aff.