( ( Unlike ( ( ( ( crustaceans or ) insects ) ( who ( possess ( external skeletons ) ) ) ) ( -LRB- ( exoskeletons -RRB- ) ) ) ) ( , ( humans ( ( ( ( ( have ( internal skeletons ) ) , ) or ) endoskeletons ) . ) ) ) )
(ROOT (S (PP (IN Unlike) (NP (NP (NNS crustaceans) (CC or) (NNS insects)) (SBAR (WHNP (WP who)) (S (VP (VBP possess) (NP (JJ external) (NNS skeletons))))) (PRN (-LRB- -LRB-) (NP (NNS exoskeletons)) (-RRB- -RRB-)))) (, ,) (NP (NNS humans)) (VP (VP (VBP have) (NP (JJ internal) (NNS skeletons))) (, ,) (CC or) (VP (VBZ endoskeletons))) (. .)))
Unlike crustaceans or insects who possess external skeletons ( exoskeletons ), humans have internal skeletons, or endoskeletons .
(ROOT (S (NP (NNS Humans)) (VP (VBP possess) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN endoskeleton))) (. .)))