( ( ( any vertebrate ) ( having ( ( ( ( ( ( four limbs ) or ) , ) ( as ( in ( the ( ( snake and ) whale ) ) ) ) ) , ) ( having ( had ( four-limbed ancestors ) ) ) ) ) ) . )
(ROOT (NP (NP (DT any) (NN vertebrate)) (VP (VBG having) (NP (NP (CD four) (NNS limbs)) (CC or) (, ,) (PP (RB as) (IN in) (NP (DT the) (NN snake) (CC and) (NN whale))) (, ,) (S (VP (VBG having) (VP (VBD had) (NP (JJ four-limbed) (NNS ancestors))))))) (. .)))
any vertebrate having four limbs or, as in the snake and whale, having had four-limbed ancestors.
(ROOT (S (NP (NNP Birds)) (VP (VBP have) (NP (CD four) (NNS limbs))) (. .)))