( ( ( The skeletons ) ( of lampreys ) ) ( ( are ( made ( of cartilage ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS skeletons)) (PP (IN of) (NP (NNS lampreys)))) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NN cartilage))))) (. .)))
The skeletons of lampreys are made of cartilage.
(ROOT (S (ADVP (RB Early) (PP (IN in) (NP (NP (DT the) (NN development)) (PP (IN of) (NP (DT a) (JJ human) (NN fetus)))))) (, ,) (NP (DT the) (NN skeleton)) (VP (VBZ is) (VP (VBN made) (ADVP (RB entirely)) (PP (IN of) (NP (NN cartilage))))) (. .)))