( Reptiles ( ( are ( ( ( ( tetrapods and ) amniotes ) , ) ( ( animals ( whose embryos ) ) ( are ( surrounded ( by ( an ( amniotic membrane ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Reptiles)) (VP (VBP are) (NP (NP (NNS tetrapods) (CC and) (NNS amniotes)) (, ,) (SBAR (WHNP (WHNP (NNS animals)) (NP (WP$ whose) (NNS embryos))) (S (VP (VBP are) (VP (VBN surrounded) (PP (IN by) (NP (DT an) (JJ amniotic) (NN membrane))))))))) (. .)))
Reptiles are tetrapods and amniotes , animals whose embryos are surrounded by an amniotic membrane .
(ROOT (S (SBAR (IN Because) (S (NP (PRP$ their) (NNS embryos)) (VP (VBP are) (VP (VBN surrounded) (PP (IN by) (NP (DT a) (JJ thin) (NN membrane))))))) (, ,) (NP (NNS reptiles)) (VP (VBP are) (VP (VBN considered) (NP (NNS amniotes)))) (. .)))