( ( Air-breathing ( in lungfishes ) ) ( ( ( ( ( ( is not ) ( considered ( to ( be ( ( a ( shared specialization ) ) ( with tetrapods ) ) ) ) ) ) , ) but ) ( evolved independently ) ) . ) )
(ROOT (S (NP (NP (NN Air-breathing)) (PP (IN in) (NP (NNS lungfishes)))) (VP (VP (VBZ is) (RB not) (VP (VBN considered) (S (VP (TO to) (VP (VB be) (NP (NP (DT a) (VBN shared) (NN specialization)) (PP (IN with) (NP (NNS tetrapods))))))))) (, ,) (CC but) (VP (VBD evolved) (ADVP (RB independently)))) (. .)))
Air-breathing in lungfishes is not considered to be a shared specialization with tetrapods, but evolved independently.
(ROOT (S (NP (NNS Caecillians)) (VP (VBD evolved) (PP (IN from) (NP (JJ tetrapod) (NNS ancestors)))) (. .)))