( ( Human skeletons ) ( ( are ( ( internal ones ) ( called endoskeletons ) ) ) . ) )
(ROOT (S (NP (NNP Human) (NNS skeletons)) (VP (VBP are) (NP (NP (JJ internal) (NNS ones)) (VP (VBN called) (NP (NNS endoskeletons))))) (. .)))
Human skeletons are internal ones called endoskeletons .
(ROOT (S (NP (NNS Humans)) (VP (VBP possess) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN endoskeleton))) (. .)))