Abstract During the 20th century, no ostracods zonal scales for the Jurassic of the East European Platform (EEP) were recognized. At that time, only ostracod assemblages characterizing substages or some ammonite zones were described. First-generation scales, developed at the turn of the 20th and 21st centuries, consisted of ostracod beds correlated at best with substages and were therefore poorly detailed. The second-generation scale, comprising zones, subzones, and beds correlated with ammonite zones, is currently the most detailed of all Jurassic micropaleontological scales of the EEP, second only to ammonites. A third-generation ostracod scale, based on phylogenetic and paleogeographic reconstructions, is now under development. It consists of lineage zones and migration zones and is correlated with ammonite biohorizons.
Е. М. Тесакова (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: