Micropaleontology is the study of fossils that are so small that they
are best studied under a microscope. These tiny remains are called
microfossils and usually represent the shells or fragments of minute
plants or animals. Because of their small size, microfossils can be
brought out of wells without being damaged by the mechanics of drilling
or coring. For this reason microfossils are particularly valuable to the
petroleum geologist who uses them to identify rock formations thousands
of feet below the surface.