( Diatoms ( ( are ( ( the ( most ( numerous ( unicellular algae ) ) ) ) ( in ( the oceans ) ) ) ) . ) )
(ROOT (S (NP (NNS Diatoms)) (VP (VBP are) (NP (NP (DT the) (JJS most) (JJ numerous) (NN unicellular) (NN algae)) (PP (IN in) (NP (DT the) (NNS oceans))))) (. .)))
Diatoms are the most numerous unicellular algae in the oceans.
(ROOT (S (NP (RBS Most) (JJ red) (NN algae) (NNS species)) (VP (VBP live) (PP (IN in) (NP (NNS oceans)))) (. .)))