ABSTRACT
Several decades ago, almost no diatomist would have been interested in historical biogeography, as the notion that there were any reasonable levels of species endemism to be worthy of study would have been disputed (for a review see Kociolek and Spaulding 2000). This viewpoint, with very few exceptions, would have applied to diatom species occurring on almost any and every part of the globe, not just Australia or Australasia. Any historical perspective on geographical distribution is intimately tied to endemism, for without endemic taxa there would be no unique patterns of distribution to explain. When focusing on any particular region, whatever size that region might be – a pond, an ancient lake, even a continent as physically large as Australia – the issue of diatom endemism arises, but usually in the context of a lack of expectation, rather than its extent (Williams 2011).
