Most species survive for a few million years at most before they become extinct, so the correct identification of fossil species is a useful means of dating sedimentary rocks.
(Most species; survive; T:for a few million years at most; T:before they become extinct) (they; become; extinct) (the correct identification of fossil species; is; a useful means of dating sedimentary rocks)
Most species they the correct identification of fossil species
survive become is
T:for a few million years at most T:before they become extinct
extinct
a useful means of dating sedimentary rocks