The fossil record of skeletons of small organisms, typically 1–3000 μm in size, extends into the deep Precambrian. Some of the earliest putative microfossils are prokaryotic organisms from the Archaean, while the earliest putative eukaryote microfossils are known from the Palaeo-proterozoic. Eukaryotic microfossils include unicellular forms such as foraminifera and radiolarians, and animals such as ostracods and conodonts. While widely applied to biostratigraphical and palaeoenvironmental investigations in geological contexts, microfossils have an increasing importance in archaeological and forensic studies. Their small size, skeletal robustness, remarkable range of morphologies, wide distribution and huge numbers in small samples have proved decisive in the provenance of archaeological and forensic evidence. Further, they provide environmental context for the increasing influence of humans on the landscape from Palaeolithic to Classical cultures.