Forty Permian conodont biozones are summarized and 35 additional regional zones are correlated. The Lower Permian is largely zoned on the basis of partial range lineage interval zones of species of Streptognathodus, Sweetognathus, Neostreptognathodus and Mesogondolella. The Middle and Upper Permian are zoned, respectively, on the basis of partial range lineage interval zones of species of Jinogondolella and Clarkina. The ranges of all key taxa to develop this zonation are depicted in relation to the geochronological ages of Permian stages. The lowest Permian succession has been astronomically tuned with 400 kyr cyclothems linked to interpolated ages in the Uralian succession.
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The Palaeozoic Era ends with the c. 47-million-year-long Permian Period. This was a major juncture in Earth history when the vast Pangean supercontinent continued its assembly and the global biota suffered the most extensive biotic decimation of the Phanerozoic, the end-Permian mass extinction. It was also the time of accumulation of vast mineral and energy deposits, notably of salt and petroleum. The temporal ordering of geological and biotic events during Permian time is, therefore, critical to the interpretation of some unique and pivotal events in Earth history. This temporal ordering is based mostly on the Permian timescale, which has been developed and refined for nearly two centuries. This book reviews the history of the development of the Permian chronostratigraphic scale. It also includes comprehensive analyses of Permian radioisotopic ages, magnetostratigraphy, isotope-based correlations, and timescale-relevant marine and non-marine biostratigraphy and biochronology.