( ( ( ( ( The bivalves ) , ) or ) ( two-shell mollusks ) ) ( ( include ( ( ( ( ( ( the clams ) , ) scallops ) , ) and ) oysters ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS bivalves)) (, ,) (CC or) (NP (JJ two-shell) (NNS mollusks))) (VP (VBP include) (NP (NP (DT the) (NNS clams)) (, ,) (NP (NNS scallops)) (, ,) (CC and) (NP (NNS oysters)))) (. .)))
The bivalves, or two-shell mollusks include the clams, scallops, and oysters.
(ROOT (S (NP (DT A) (NN scallop)) (VP (VBZ is) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN mollusk))) (. .)))