( ( ( Plant-Eater - ) ( mainly ( eats plants ) ) ) . )
(ROOT (X (NP (NN Plant-Eater)) (: -) (FRAG (VP (ADVP (RB mainly)) (VBZ eats) (NP (NNS plants)))) (. .)))
Plant-Eater- mainly eats plants.
(ROOT (S (NP (DT The) (NN heterotroph)) (VP (VBZ eats) (NP (UCP (ADJP (JJ only)) (CC or) (ADVP (RB mainly))) (NNS plants))) (. .)))