( organism ( that ( eats ( only plants ) ) ) )
(ROOT (FRAG (NP (NN organism)) (SBAR (WHNP (WDT that)) (S (VP (VBZ eats) (NP (JJ only) (NNS plants)))))))
organism that eats only plants
(ROOT (S (NP (DT The) (NN heterotroph)) (VP (VBZ eats) (NP (UCP (ADJP (JJ only)) (CC or) (ADVP (RB mainly))) (NNS plants))) (. .)))