“…Understanding the dynamics of de‐oxygenation during this short‐lived event, estimated as lasting between 450 kyr and 900 kyr (Arthur & Premoli‐Silva, ; Kuhnt et al ., ; Sageman et al ., ; Voigt et al ., ; Eldrett et al ., ; Batenburg et al ., ), and similar organic carbon burial events throughout Earth history, has been a major priority in the search to unravel the climate forcing, biological feedbacks and related redox dynamics of the ocean during biotic extinction events (Bambach, ). There is mounting evidence for widespread anoxic and specifically euxinic conditions during OAE 2 based on diverse geochemical proxies for local bottom‐water redox at multiple locations (Brumsack, ; Turgeon & Brumsack, ; Jenkyns et al ., ; van Bentum et al ., ; Pearce et al ., ; Lu et al ., ; Hetzel et al ., ; Owens et al ., , ; Westermann et al ., ; Dickson et al ., ; Goldberg et al ., ), including evidence for photic‐zone euxinia (Sinninghe Damsté & Köster, ; Kuypers et al ., ; Pancost et al ., ; van Bentum et al ., ). Numerical ocean modelling suggests that 50% (by volume) of the global ocean was anoxic during the OAE (Monteiro et al ., ).…”