I love this hypothesis but it's mostly been disproven recently. Fungi were able to degrade it almost immediately I did some reading and it seems the actual pot

I love this hypothesis but it's mostly been disproven recently. Fungi were able to degrade it almost immediately I did some reading and it seems the actual potential mass extinction caused by trees was this: Their roots/mycorrhiza dug deep into the earth and brought up large amounts of phosphorus. Occassional mudslides or other events would then cause this soil to slide into the ocean and create an algae bloom which deprived the ocean of oxygen. Very similar to what's happening today with agricultural runoff of fertilizers