( ( ( Imprints ( of ( ( ( ( ( ( ( leaves , ) shells ) , ) insects ) , ) or ) ( other items ) ) ) ) ( in ( the rock ) ) ) . )
(ROOT (NP (NP (NNS Imprints)) (PP (IN of) (NP (NP (NNS leaves)) (, ,) (NP (NNS shells)) (, ,) (NP (NNS insects)) (, ,) (CC or) (NP (JJ other) (NNS items)))) (PP (IN in) (NP (DT the) (NN rock))) (. .)))
Imprints of leaves, shells, insects, or other  items in the rock.
(ROOT (S (NP (DT A) (NN mold)) (VP (VBZ is) (NP (NP (DT an) (NN imprint)) (PP (IN of) (NP (NP (DT an) (NN organism)) (VP (VBN left) (PP (IN in) (NP (NN rock)))))))) (. .)))