that this has forced highly specialised evolution amongst Australian flora to obtain minimal nutrient supplies. The fact that soil formation is simply not occurring makes ecologically sustainable management even more difficult. However, paleosols often contain the most exceptional biodiversity due to the absence of competition. Taxonomic classification The record of paleosols extends into the Precambrian in Earth's history, with rare paleosols older than 2.5 billion years. Geology, biology, and the atmosphere all changed significantly over that time, with dramatic shifts at the Great Oxidation Event (2.42 billion years ago) and during the Paleozoic, when complex animals and land plants proliferated. Consequently, our modern soil classification system cannot be readily applied to paleosols. For example, a modern alfisol - broadly defined as a forest soil - would not have existed prior to the evolution of trees. More problematically, it is specifically defined by chemical properties that would not be preserved in the rock record. While modern soil orders are often used to describe paleosols in a qualitative sense, a paleosol-specific naming scheme has been proposed, although it is only used sporadically in the literature. Until a paleosol-specific naming scheme is fully adopted, many paleopedologists have stuck to using the taxonomic classification of soils provided by the United States Department of Agriculture. This soil taxonomy attempted to use the measurable properties and objective features within soils to classify them. The U.S. Soil Taxonomy also developed a hierarchical structure among the different soil taxa, classifying the soils initially at a general level, then assigning soils to progressively more limited subdivisions. This taxonomy does come with drawbacks, including an emphasis on observable features, new nomenclature, and hierarchical organization. The emphasis on observable features can make the soil taxonomy similar in appearance to a legal document. The nomenclature is off-putting, and alien upon first interaction. The hierarchical structure cannot be applied more deeply than the order level regarding paleosols. However, despite these drawbacks, the U.S. Soil Taxonomy is still the most comprehensive and influential soil classification system to date. To distinguish and identify these paleosols from one another, certain diagnostic horizons and features need to be taken into account. For instance, all paleosols have an A horizon, but histosols have an O horizon above the A horizon. Paleosol identification Rye & Holland (1998) laid out five criteria for identifying a paleosol. While this was prompted by the need for more stringent identification of Precambrian paleosols,