Ecostratigraphy: the limits of applicability

Abstract

Chronostratigraphy recalls a set of arbitrarily chosen reference time-planes. In turn, ecostratigraphic time-scale refers to remarkable events recorded in the stratigraphic distribution of species. Biotic evolution appears as the model of the geologic time as conceived in terms of both the chronostratigraphic and ecostratigraphic time-scale. The basic assumption about the evolution, required by ecostratigraphy, is that either there is the process of community evolution, or co-evolution among large groups of species plays an important role in the biotic evolution. There is no community evolution in the nature because ecological communities themselves are merely an epiphenomenon of species evolution. Empirical data show that co-evolution is insignificant among planktic organisms; but it is important among shallow-marine benthic organisms. This observation sets the Iimits of applicability to the ecostratigraphic time-scale which appears adequate to that part of the fossil record that represents shallow-marine realm, but not to the record of pelagic realm.