( ( ( ( ( ( The relief ) ( on ( the skin ) ) ) , ) ( caused ( by ( the scales ) ) ) ) , ) ( ( is ( ( ( ( a ( major characteristic ) ) ( of ( ( reptiles . ) ( ( The ( watertight skin ) ) ( is ( ( , ( ( unlike ( most amphibians ) ) , ) ) dry ) ) ) ) ) ) , ) ( ( allowing reptiles ) ( to ( live ( in ( dry habitats ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN relief)) (PP (IN on) (NP (DT the) (NN skin))) (, ,) (VP (VBN caused) (PP (IN by) (NP (DT the) (NNS scales)))) (, ,)) (VP (VBZ is) (NP (NP (DT a) (JJ major) (NN characteristic)) (PP (IN of) (NP (NP (NNP reptiles) (. .)) (SBAR (S (NP (DT The) (NN watertight) (NN skin)) (VP (VBZ is) (ADJP (PRN (, ,) (PP (IN unlike) (NP (JJS most) (NNS amphibians))) (, ,)) (JJ dry))))))) (, ,) (VP (VBG allowing) (NP (NNS reptiles)) (S (VP (TO to) (VP (VB live) (PP (IN in) (NP (JJ dry) (NNS habitats))))))))) (. .)))
The relief on the skin, caused by the scales, is a major characteristic of reptiles. The watertight skin is, unlike most amphibians, dry, allowing reptiles to live in dry habitats.
(ROOT (S (NP (NP (NNP Dry) (NN skin)) (CC and) (NP (NNS scales))) (VP (VBP are) (NP (NP (NN part)) (PP (IN of) (NP (NP (DT an) (NN animal)) (SBAR (WHNP (WDT that)) (S (VP (MD would) (ADVP (RBS most) (RB likely)) (VP (VB be) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN reptile)))))))))))) (. .)))