( ( Paramecium bursaria ) ( ( is ( ( a member ) ( of ( ( a ( large group ) ) ( of ( ( ( ( ( ( complex , ) but ) ( single celled ) ) , ) protists ) ( -LRB- ( eukaryotes -RRB- ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Paramecium) (NNP bursaria)) (VP (VBZ is) (NP (NP (DT a) (NN member)) (PP (IN of) (NP (NP (DT a) (JJ large) (NN group)) (PP (IN of) (NP (NP (ADJP (ADJP (JJ complex)) (, ,) (CC but) (ADJP (JJ single) (JJ celled)) (, ,)) (NNS protists)) (PRN (-LRB- -LRB-) (NP (NNS eukaryotes)) (-RRB- -RRB-)))))))) (. .)))
Paramecium bursaria is a member of a large group of complex, but single celled, protists (eukaryotes).
(ROOT (S (NP (NNS Protists)) (VP (VBP are) (VP (VBN thought) (S (VP (TO to) (VP (VB be) (NP (DT the) (JJS oldest) (NNS eukaryotes))))))) (. .)))