This textbook will appeal to students and graduates making their first steps in the application of both microfossils and stratigraphy. It presents, in detail, the historical development of microfossil biostratigraphy, from its birth to the emergence of sequence stratigraphy, including its roots in classical biostratigraphy. The interplay between the academic and economical challenges, on one hand, and developments in microfossil biostratigraphy, on the other, is explored thoroughly. The book also presents an introduction to the scientific concepts used in microfossil biostratigraphy practice, and the uses in microbiostratigraphy of 25 groups of microfossils, such as algae, protistans, reproductive plant debris, invertebrates, chordates and vertebrates, and microproblematica groups. It also provides a numerical method to calculate the biostratigraphical resolution of these microfossil groups.