Stages in evolution of organisms and nature of biostratigraphic boundaries: Inferences from phylogeny of Permian brachiopod tribe Horridoniini

摘要

Stages defined in the reconstructed phylogenetic lineage of the tribe Horridoniini widespread in Boreal basins of the Permian represent a promising tool for a distant interregional correlation. At the same time, they appear to be useless as chronostratigraphic markers. This seemingly paradoxical inconsistency is directly concerning the methodology of stratigraphy, the essence of biostratigraphic boundaries. Point and line are the ideal (mathematical) notions, principal ones for analysis of quantitative time relationships in physics. In contrast, traditional stratigraphy interprets these relationships based on real (material) reference criteria such as intervals of rock successions. This ontological problem-what should be considered of prime importance in stratigoraphy (point and line or interval and volume)-is discussed using as an example the correlation potential of a recently defined phyletic succession of genera in the tribe Horridoniini.