( They ( also ( ( made ( use ( of ( ( sharp spicules ) ( of ( ( ( ( ( stone , ) flint ) , ) and ) bone ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (PRP They)) (ADVP (RB also)) (VP (VBD made) (NP (NP (NN use)) (PP (IN of) (NP (NP (JJ sharp) (NNS spicules)) (PP (IN of) (NP (NP (NN stone)) (, ,) (NP (NN flint)) (, ,) (CC and) (NP (NN bone)))))))) (. .)))
They also made use of sharp spicules of stone, flint, and bone.
(ROOT (S (NP (NP (DT The) (JJ sharp) (NNS projections)) (SBAR (IN that) (S (NP (JJ specialized) (NNS cells)) (VP (VBP grow))))) (VP (VBP are) (VP (VBN called) (NP (NNS spicules)))) (. .)))