A short history of the Ordovician System: from overlapping unit stratotypes to global stratotype sections and points

Abstract The Ordovician System was introduced by Charles Lapworth as a solution to the overlapping unit stratotypes loosely defined Adam Sedgwick, for Cambrian, and Roderick Murchison, Silurian. has emerged one of longest most significant geological periods. Following an interval intensive research all key regions globe, in type areas England Wales have been replaced seven global stages three series based on Global Stratotype Sections Points (GSSPs), enhancing definition these chronostratigraphic units facilitating correlation. As consequence, biological events during period can be recognized magnitude significance biotic originations extinctions understood with some confidence.