( ( Coral reefs ) ( actually ( ( are ( communities ( of ( ( ( hundreds ( of thousands ) ) ( of ( tiny animals ) ) ) ( called ( ( ( coral polyps ) , ) ( which ( grow ( in ( ( sunlit shallows ) ( of ( warm ( , ( clear ( marine waters ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (JJ Coral) (NNS reefs)) (ADVP (RB actually)) (VP (VBP are) (NP (NP (NNS communities)) (PP (IN of) (NP (NP (QP (NNS hundreds) (IN of) (NNS thousands))) (PP (IN of) (NP (JJ tiny) (NNS animals))) (VP (VBN called) (NP (NP (NN coral) (NNS polyps)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP grow) (PP (IN in) (NP (NP (JJ sunlit) (NNS shallows)) (PP (IN of) (NP (JJ warm) (, ,) (JJ clear) (JJ marine) (NNS waters)))))))))))))) (. .)))
Coral reefs actually are communities of hundreds of thousands of tiny animals called coral polyps, which grow in sunlit shallows of warm, clear marine waters.
(ROOT (S (NP (NP (NNP Ocean) (NNP ridges)) (VP (VBN formed) (PP (IN by) (NP (NP (JJ marine) (NNS invertebrates)) (VP (VBG living) (PP (IN in) (NP (JJ warm) (JJ shallow) (NNS waters))) (PP (IN within) (NP (NP (DT the) (JJ photic) (NN zone)) (PP (IN of) (NP (DT the) (NN ocean)))))))))) (VP (VBP are) (VP (VBN called) (NP (NN coral) (NNS reefs)))) (. .)))