( Heterobranchia ( ( is ( one ( of ( ( the ( main clades ) ) ( of gastropods ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Heterobranchia)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT the) (JJ main) (NNS clades)) (PP (IN of) (NP (NNS gastropods))))))) (. .)))
Heterobranchia is one of the main clades of gastropods.
(ROOT (S (NP (DT A) (NN clade)) (VP (VBZ is) (NP (NP (CD one) (NN way)) (PP (IN of) (NP (VBG classifying) (NNS organisms))))) (. .)))