This photographic guide will assist scientists working with archaeological plant or insect remains in the identification of calcium-phosphate replaced biological remains. Diagnostic criteria and images are presented for the most commonly occurring taxa found as mineralised remains in cesspits, drains and middens, dating from the prehistoric to post-medieval periods . Phosphatic mineralisation primarily preserves soft tissues and often results in the loss of diagnostic features typically seen in other types of preservation, particularly of the thickened, protective outer layers (pericarps...