Eucalypts have influenced the fire ecology of the Australian landscape more than any other plant group. They are the iconic plant taxon in the Australian vegetation today, but their origin, early evolution and migration remain poorly understood, mostly because of a remarkably sparse and underworked fossil record. However, a recent major macrofossil find in southern South America, coupled with increasing sophistication of molecular phylogenetic and palynological research allow for a more comprehensive summary of the likely early history of this group of genera. It is likely that the origin was close to the Cretaceous–Paleogene boundary, somewhere in the Weddellian Biogeographic Province (which includes southern South America, western Antarctica and south-eastern Australia), in an area with high natural fire frequency. Evidence for the early record of eucalypts in Australia and their eventual spread across the continent, leading to their current dominance of the Australian plant biomass is growing and is consistent with a drying climate and increasing fire frequency following a very wet period during the Paleogene. The causes of the extinction of eucalypts from South America and probably New Zealand are considered, but remain obscure.
The discovery of Early Miocene Asteliaceae fossils at Foulden Maar in southern New Zealand provided a good opportunity to assess the usefulness of cuticular information for identifying members in this family. On the basis of cuticular morphology, the Foulden specimens are assigned to Astelia Banks & Sol. ex R.Br. and described as a new species, A. antiquua Maciunas et al. They are shown to have some affinities with A. alpina, A. linearis and also an apparently unnamed Astelia taxon from southern Westland, New Zealand. Although cuticular characteristics alone were of help in identifying individual species, the addition of gross morphological characters facilitated the differentiation between Asteliaceae genera, greatly improving the phylogenetic placement of the fossil. On the basis of analysis of the combined data, Astelia and Collospermum formed a clade and were sister to a Milligania and Neoastelia clade, albeit with most branches showing little overall bootstrap support.
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