( ( Except ( for ( the crocodilians ) ) ) ( , ( they ( ( have ( a ( three-chambered heart ) ) ) . ) ) ) )
(ROOT (S (PP (IN Except) (PP (IN for) (NP (DT the) (NNS crocodilians)))) (, ,) (NP (PRP they)) (VP (VBP have) (NP (DT a) (JJ three-chambered) (NN heart))) (. .)))
Except for the crocodilians, they have a three-chambered heart.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (NNS chambers)) (PP (IN in) (NP (DT an) (NN amphibian) (NN heart))))) (. .)))