( ( ( Both ( extinction pulses ) ) ( would ( ( contribute ( to ( ( dramatic reduction ) ( in ( oxygen levels ) ) ) ) ) ( on Earth ) ) ) ) ( , ( ( a condition ) ( ( called ( ( anoxia , ) ( known ( to ( have ( been ( associated ( with ( the ( Permian ( mass extinction ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (DT Both) (NN extinction) (NNS pulses)) (VP (MD would) (VP (VB contribute) (PP (TO to) (NP (NP (JJ dramatic) (NN reduction)) (PP (IN in) (NP (NN oxygen) (NNS levels))))) (PP (IN on) (NP (NNP Earth)))))) (, ,) (NP (DT a) (NN condition)) (VP (VBD called) (NP (NP (NN anoxia)) (, ,) (VP (VBN known) (S (VP (TO to) (VP (VB have) (VP (VBN been) (VP (VBN associated) (PP (IN with) (NP (DT the) (JJ Permian) (NN mass) (NN extinction))))))))))) (. .)))
Both extinction pulses would contribute to dramatic reduction in oxygen levels on Earth, a condition called anoxia, known to have been associated with the Permian mass extinction.
(ROOT (S (NP (NP (ADJP (JJ Sudden) (CC and) (JJ dramatic)) (NNS losses)) (PP (IN of) (NP (NN biodiversity)))) (VP (VBP are) (VP (VBN called) (NP (JJ mass) (NN extinction)))) (. .)))