( The ( Mammals ( Four-chambered ( heart . ) ) ) )
(ROOT (NP (DT The) (JJ Mammals) (JJ Four-chambered) (NN heart) (. .)))
The Mammals Four-chambered heart.
(ROOT (S (PP (IN Like) (NP (NP (DT all) (NNS tetrapods)) (PP (IN except) (NP (NNS birds) (CC and) (NNS mammals))))) (, ,) (NP (NNS frogs)) (VP (VBP possess) (NP (NP (DT a) (NN heart)) (PP (IN with) (NP (CD three) (NNS chambers))))) (. .)))