“…The growing body of knowledge about the SPICE necessitates hypotheses that link the observed correspondence between the initiation of the δ 13 C excursion, the synchronous excursions in δ 34 S, and the extinctions marking the Marjumaniid/Pterocephaliid biomere boundary (and coeval extinctions observed on other paleocontinents) causally (Gerhardt & Gill, ). Numerous potential environmental drivers have been explored including changes in temperature (Elrick, Rieboldt, Saltzman, & McKay, ; Palmer, ; Perfetta et al., ), sea level (Glumac & Walker, ; Saltzman et al., ), ocean circulation (Saltzman et al., ), nutrient availability (Saltzman et al., ), as well as expanded anoxia (Edwards et al., ; Saltzman et al., ) and euxinia (Dahl et al., ; Gill et al., ). It is important to note that none of these drivers are mutually exclusive and possible scenarios where a number of these factors worked in concert require continued consideration.…”