Paleontology is a basic subject, which focuses on the study of palaeontological classification, ecology, origin and evolution. Stratigraphy, which correlates with Paleonthology, studies the forming orders, evolution in time and space and crust development and their disciplines. Paleontology and Stratigraphy is a basic subject in the study field of geology. It emphases and assigns relative ages of rock strata by using the shapes, structures, ecology and classification and evolution of fossil assemblages contained within them. Usually the aim is correlation, demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at some other section. There are two aspects in this subject: application studies in the fields of (1) oil-gas exploration and development, and (2) marine micro-paleontoloyg and marine geology.