( Benthos ( ( are ( ( living things ) ( on ( the ( ocean floor ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Benthos)) (VP (VBP are) (VP (VBG living) (NP (NNS things)) (PP (IN on) (NP (DT the) (NN ocean) (NN floor))))) (. .)))
Benthos are living things on the ocean floor.
(ROOT (S (NP (NP (VBG Living) (NNS things)) (PP (IN on) (NP (DT the) (NN ocean) (NN floor)))) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NNS benthos))))) (. .)))
Living things on the ocean floor are known as benthos.