Figure F24. Cores that contain the appearance and sudden disappearance of prisms of Inoceramus. In Sections 198-1209C-21H-1 through 198-1209C-21H-21H-3, and 198-1210B-28H-5 and 1209B-28H-6. The interval shown lies in the same biostratigraphic interval as the extinction in the deep sea. The small arrows indicate positions of prisms in cores, and large arrows show the disappearance level.