Well preserved calcareous microfossils, such as ostracods, can be extracted from strongly lithified Palaeozoic limestones of the Lachlan Fold Belt using highly concentrated acetic acid (95%) with minimal dissociation. This technique differs from the more dilute acetic acid or formic acid methods which are commonly used during the extraction of phosphatic microfossils, such as conodonts, and which destroy many calcitic specimens. Correlations made between representative microfossil assemblages and host rock thin sections expand knowledge of palaeoenvironmental parameters attributed to microfacies.