( ( Characteristics ( of ( Vertebrates ( ( The ( main ( distinguishing feature ) ) ) ( of vertebrates ) ) ) ) ) ( ( is ( ( ( ( their ( vertebral column ) ) , ) or ) ( backbone ( -LRB- ( ( see ( Figure 19.1 ) ) -RRB- ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Characteristics)) (PP (IN of) (NP (NNP Vertebrates) (NP (NP (DT The) (JJ main) (JJ distinguishing) (NN feature)) (PP (IN of) (NP (NNS vertebrates))))))) (VP (VBZ is) (NP (NP (PRP$ their) (JJ vertebral) (NN column)) (, ,) (CC or) (NP (NP (NN backbone)) (PRN (-LRB- -LRB-) (S (VP (VB see) (NP (NN Figure) (NNS 19.1)))) (-RRB- -RRB-))))) (. .)))
Characteristics of Vertebrates   The main distinguishing feature of vertebrates is their vertebral column, or backbone (see Figure 19.1).
(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.