These microfossils range from 200um to 5mm are the teeth of a soft bodied creature. These are composed of calcium phosphate, apatite, occur in pairs are known as conodont elements. The earliest Conodonts are found in Precambrian rocks and died out in the Permo-Triassic event.
These are marine, planktonic animals, which range from 30um to 2mm. They are composed of silica and occupied niches near the surface to hundreds of metres depth. They are preserved at depths below the CCD and are easy to recover. They are excellent stratigraphic and palaeo-environmental tools.