( ( Pioneering ( new research ) ) ( ( has ( ( debunked ( the theory ) ) ( that ( ( ( the asteroid ) ( that ( is ( thought ( to ( have ( led ( to ( ( the extinction ) ( of dinosaurs ) ) ) ) ) ) ) ) ) ) ( also ( caused ( ( vast ( global firestorms ) ) ( that ( ravaged ( planet Earth ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (S (VP (VBG Pioneering) (NP (JJ new) (NN research)))) (VP (VBZ has) (VP (VBN debunked) (NP (DT the) (NN theory)) (SBAR (IN that) (S (NP (NP (DT the) (NN asteroid)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN thought) (S (VP (TO to) (VP (VB have) (VP (VBN led) (PP (TO to) (NP (NP (DT the) (NN extinction)) (PP (IN of) (NP (NNS dinosaurs)))))))))))))) (ADVP (RB also)) (VP (VBD caused) (NP (NP (JJ vast) (JJ global) (NNS firestorms)) (SBAR (WHNP (WDT that)) (S (VP (VBN ravaged) (NP (NN planet) (NN Earth))))))))))) (. .)))
Pioneering new research has debunked the theory that the asteroid that is thought to have led to the extinction of dinosaurs also caused vast global firestorms that ravaged planet Earth.
(ROOT (S (PP (IN In) (NP (DT the) (NN past))) (, ,) (NP (NP (NNS asteroids)) (VP (VBG colliding) (PP (IN with) (NP (NN planet) (NN earth))))) (VP (VBZ has) (VP (VBN caused) (NP (JJ many) (NNS organisms)) (S (VP (TO to) (VP (VB die) (PRT (RP off))))))) (. .)))