( ( ( ( ( All but ) one ) group ) ( of ( these ( -LRB- ( ( the hagfishes ) -RRB- ) ) ) ) ) ( also ( ( ( convert ( their notochord ) ) ( into ( ( a ( vertebral ( ( column or ) backbone ) ) ) ( thus ( qualifying ( as vertebrates ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (QP (DT All) (CC but) (CD one)) (NN group)) (PP (IN of) (NP (NP (DT these)) (PRN (-LRB- -LRB-) (NP (DT the) (NN hagfishes)) (-RRB- -RRB-))))) (ADVP (RB also)) (VP (VB convert) (NP (PRP$ their) (NN notochord)) (PP (IN into) (NP (NP (DT a) (JJ vertebral) (NN column) (CC or) (NN backbone)) (VP (ADVP (RB thus)) (VBG qualifying) (PP (IN as) (NP (NNS vertebrates))))))) (. .)))
All but one group of these (the hagfishes) also convert their notochord into a vertebral column or backbone thus qualifying as vertebrates.
(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.