Causal biostratigraphy means an approach to stratigraphic problems based on ecosystem analysis of interrelations between geological events and organic evolution. Thc succession of ecosystems is controlled mainly by climatic cycles. Stratigraphic units correspond to palececosystems. The units of higher ranks which are defined by changes of major biomes correspond to paleobiospheres. Their boundaries are designated by replacement of dominant types within the stratoecotones. Reconstruction of catenae, analysis of vicarious catenae systems, and correlation by cliserer are among the most useful methods of causal biostratigraphy.