( ( In ( ( direct contrast ) ( to ( ( arthropods , ) ( which ( live ( inside ( an exoskeleton ) ) ) ) ) ) ) ) ( , ( vertebrates ( ( have ( evolved ( ( ( ( a ( hard ( internal skeleton ) ) ) , ) or ) endoskeleton ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (JJ direct) (NN contrast)) (PP (TO to) (NP (NP (NNS arthropods)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP live) (PP (IN inside) (NP (DT an) (NN exoskeleton)))))))))) (, ,) (NP (NNS vertebrates)) (VP (VBP have) (VP (VBN evolved) (NP (NP (DT a) (JJ hard) (JJ internal) (NN skeleton)) (, ,) (CC or) (NP (NN endoskeleton))))) (. .)))
In direct contrast to arthropods, which live inside an exoskeleton, vertebrates have evolved a hard internal skeleton, or endoskeleton.
(ROOT (S (NP (DT The) (JJ vertebrate) (NN endoskeleton)) (VP (MD can) (ADVP (RB also)) (VP (VB be) (VP (VBN called) (S (NP (DT a) (-LRB- -LRB-) (NN n) (-RRB- -RRB-)) (NP (JJ internal) (NN skeleton)))))) (. .)))