( ( ( The ( mesohyl functions ) ) ( as ( ( an endoskeleton ) ( in most ) ) ) ) ( ( ( ( sponges , ) and ) ( is ( ( ( the ( only skeleton ) ) ( in ( soft sponges ) ) ) ( that ( encrust ( ( hard surfaces ) ( such ( as rocks ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ mesohyl) (NNS functions)) (PP (IN as) (NP (NP (DT an) (NN endoskeleton)) (PP (IN in) (NP (RBS most)))))) (VP (VP (VBZ sponges)) (, ,) (CC and) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN skeleton)) (PP (IN in) (NP (JJ soft) (NNS sponges))) (SBAR (WHNP (WDT that)) (S (VP (VBP encrust) (NP (NP (JJ hard) (NNS surfaces)) (PP (JJ such) (IN as) (NP (NNS rocks)))))))))) (. .)))
The mesohyl functions as an endoskeleton in most sponges, and is the only skeleton in soft sponges that encrust hard surfaces such as rocks.
(ROOT (S (NP (NNS Humans)) (VP (VBP possess) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN endoskeleton))) (. .)))