( Reptiles ( ( ( evolved ( from ( amphibian ancestors ) ) ) ( by ( Permian period ) ) ) . ) )
(ROOT (S (NP (NNS Reptiles)) (VP (VBD evolved) (PP (IN from) (NP (NN amphibian) (NNS ancestors))) (PP (IN by) (NP (JJ Permian) (NN period)))) (. .)))
Reptiles evolved from amphibian ancestors by Permian period.
(ROOT (S (NP (NNP Birds)) (VP (VBD evolved) (PP (IN from) (NP (JJ reptile) (NNS ancestors)))) (. .)))