( ( ( ( ( ( Primitive fish ) ( have ( a ( four-chambered heart ) ) ) ) , ) but ) ( ( the chambers ) ( are ( ( arranged sequentially ) ( so ( that ( ( this ( primitive heart ) ) ( is ( quite ( unlike ( ( the ( four-chambered hearts ) ) ( of ( ( mammals and ) birds ) ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Primitive) (NN fish)) (VP (VBP have) (NP (DT a) (JJ four-chambered) (NN heart)))) (, ,) (CC but) (S (NP (DT the) (NNS chambers)) (VP (VBP are) (VP (VBN arranged) (ADVP (RB sequentially)) (SBAR (RB so) (IN that) (S (NP (DT this) (JJ primitive) (NN heart)) (VP (VBZ is) (ADJP (RB quite) (PP (IN unlike) (NP (NP (DT the) (JJ four-chambered) (NNS hearts)) (PP (IN of) (NP (NNS mammals) (CC and) (NNS birds)))))))))))) (. .)))
Primitive fish have a four-chambered heart, but the chambers are arranged sequentially so that this primitive heart is quite unlike the four-chambered hearts of mammals and birds.
(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))))) (. .)))