( This ( ( was ( ( the ( Triassic period ) ) ( of ( the ( Cambrian era ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBD was) (NP (NP (DT the) (JJ Triassic) (NN period)) (PP (IN of) (NP (DT the) (NNP Cambrian) (NN era))))) (. .)))
This was the Triassic period of the Cambrian era.
(ROOT (S (NP (NP (DT The) (JJ first) (NN period)) (PP (IN of) (NP (DT the) (JJ paleozoic) (NN era)))) (VP (VBD was) (VP (VBN called) (NP (NN cambrian)))) (. .)))