Ostracod Taxa as Palaeoclimate Indicators in the Quaternary

We review the utility of ostracods for palaeoclimatic reconstruction at different taxonomic levels. Ostracods can provide palaeoenvironmental information based on several approaches. The chemical and isotopic composition of their mineral shells as well as the relatively minor organic component trapped within the carbonate lattice may give direct quantitative evidence of conditions in their natural habitat. Morphological observations and detailed morphometric records of valve size, shape and outline within a species may provide subtle clues to environmental changes between different habitats or adjacent stratigraphic intervals. Uniformitarian approaches can be applied to species, genera and supra-generic classifications but with decreasing resolution and increasing uncertainty in palaeoenvironmental significance (1) the higher the taxonomic unit and (2) the older the material geologically. The classical methodology of combining the habitat and environmental preferences of individual species to infer palaeoclimatic conditions remains as valid today as when such observations were first made in the nineteenth century.