( ( Introduction ( An invertebrate ) ) ( ( is ( ( an animal ) ( without ( a ( backbone ( or ( vertebral column ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Introduction) (DT An) (NN invertebrate)) (VP (VBZ is) (NP (NP (DT an) (NN animal)) (PP (IN without) (NP (DT a) (NN backbone) (CC or) (NN vertebral) (NN column))))) (. .)))
Introduction An invertebrate is an animal without a backbone or vertebral column.
(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.