Noun
euxinia
(biology, geology) A euxinic environment, especially at critical times in the geologic past.
Anoxia seeAlso Evidence for widespread ocean anoxia (severe deficiency of oxygen) and euxinia (presence of hydrogen sulfide ) is found from the Late Permian to the Early Triassic. Source: Internet
Hypercapnia best explains the selectivity of the extinction, but anoxia and euxinia probably contributed to the high mortality of the event. Source: Internet