Baltoniodus triangularis which happened about million years ago. The Dapingian lasted for about 1.9 million years until about million years ago.

History

The Ordovician was divided into three series and six global stages in 1995. Although at the time of 2005 GSSPs for the overlying Darriwilian and underlying "second stage" had already been ratified, definition of a GSSP for the first stage of the Middle Ordovician

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