Format: ORAL

FrancisJ. Nge1,2, Barbara Rye3, Peter Wilson1, Kevin R. Thiele4, Ed Biffin2,5, Michelle Waycott2,5, Korjent van Dijk5, Matthew Barrett6

1 National Herbarium of New South Wales, Botanic Gardens of Sydney, Australian Botanic Garden, Locked Bag 6002, Mount Annan, NSW 2567, Australia 2 School of Biological Sciences, Faculty of Science, Adelaide 5000, SA, Australia 3 Western Australian Herbarium, Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre, Western Australia 6983, Australia 4 School of Biological Sciences, the University of Western Australia 6009, Australia 5 State Herbarium of South Australia, Botanic Gardens and State Herbarium, Adelaide, SA 5000, Australia 6 Australian Tropical Herbarium, Sir Robert Norman Building, James Cook University Cairns Campus, McGregor Road, Smithfield, Qld 4878, Australia

The Myrtaceae tribe Chamelaucieae is a diverse tribe predominantly distributed across Australia with over 660 species across 34 genera. The phylogenetic backbone of this tribe was previously unresolved based on studies utilising Sanger sequencing data. Here, we present an updated well-resolved phylogeny of the tribe as part of the GAP Stage 2 initiative, utilising over 400 nuclear single-copy loci (angio353 and Ozbaits). Ten out of the 11 subtribes with 33 out of the 34 genera are represented in our study. We dated the phylogeny using secondary calibrations and looked at biogeographic disjunctions across different Australian biogeographic regions using BioGeoBEARS. We also tested for environmental-dependent diversification using RPANDA. Findings from our biogeographic analyses indicate a mixture of vicariance and dispersal events across different simulated climatic scenarios (e.g., aridification of Australia since the Miocene). Biogeographic results and speciation decline detected from our phylogeny coinciding with the EoceneOligocene extinction event (33 Myr) will also be discussed.