Fig. 4.

Distribution of the DS and LAD occurrences of DCWs. (A) Number of non-DCW orders compared to DCW orders featuring a DS at either an ME or background stage (BG). (B) Distribution of DS at ME orders throughout the Big Five ME events. Hatched region of the end-Ordovician corresponds to the potentially associated Aeronian DS (DSs in ME vs. Background Stages). (C) Number of DCWs with their LAD associated with either ME or BG stages, compared to extant examples. (D) Distribution of LAD at ME orders throughout the Big Five ME events.