  The dynamical age of the universe depends upon the rate of the expansion of
the universe, which explicitly involves the dark energy equation of state
parameter $w(z)$. Consequently, the evolution of $w(z)$ has a direct imprint on
the age of the universe. We have shown that the dynamical age of the universe
as derived from CMB data can be used as an authentic criterion, being
independent of the priors like the present value of the Hubble constant $H_{0}$
and the cosmological density parameter $\Omega_{M}^{0}$, to constrain the range
of admissible values of $w$ for quiessence models and to test the physically
viable parametrizations of the equation of state $w(z) $ in kinessence models.
An upper bound on variation of dark energy density is derived and a relation
between cosmological density parameters and the transition redshift is
established.
