PLAIN- LANGUAGE SUMMARY

Preparation of fossils is essential in undertaking palaeontological disciplines such as taxonomy, biostratigraphy and palaeoecology. However, the preparator has to experiment with different methods to find those required to uncover morphological features of the fossils. A solution of acetic acid is usually used to extract non-calcareous fossils from limestones because the procedure damages calcareous fossils. A new technique, the acid-hot water method, can significantly augment such "room temperature" approaches. Although the sample is saturated with concentrated acetic acid (99-100%), no etching occurs. This lack of etching is related to an extremely low degree of dissociation. By pouring plenty of hot water on the sample, carbon dioxide is formed and disaggregates the sediment. Sieving of the sediment concentrates the calcareous fossils to grade sizes picked more easily. Compared to other methods, the acid-hot water method is an efficient and time-saving procedure.

High-pressurized water is commonly used in the cleaning of masonry and painted surfaces of house façades and flagstones. Although widely known, the technique has not obtained the attention it deserves from palaeontologists and preparators. Fossils from chalk and limestones may be prepared within a few minutes by waterblasting.