( ( In ( vertebrate chordates ) ) ( , ( it ( ( is ( replaced ( by ( ( a ( vertebral ( ( column or ) backbone ) ) ) ( long ( before maturity ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (JJ vertebrate) (NNS chordates))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN replaced) (PP (IN by) (NP (NP (DT a) (JJ vertebral) (NN column) (CC or) (NN backbone)) (ADVP (RB long) (PP (IN before) (NP (NN maturity)))))))) (. .)))
In vertebrate chordates, it is replaced by a vertebral column or backbone long before maturity.
(ROOT (S (NP (NNP Backbone)) (VP (VBZ is) (NP (NP (DT another) (NN name)) (PP (IN for) (NP (DT the) (JJ vertebral) (NN column))))) (. .)))
Backbone is another name for the vertebral column.