  The Erigone family is a C-type group in the inner main belt. Its age has been
estimated by several researchers to be less then 300 My, so it is a relatively
young cluster. Yarko-YORP Monte Carlo methods to study the chronology of the
Erigone family confirm results obtained by other groups. The Erigone family,
however, is also characterized by its interaction with the $z_2$ secular
resonance. While less than 15% of its members are currently in librating states
of this resonance, the number of objects, members of the dynamical group, in
resonant states is high enough to allow to use the study of dynamics inside the
$z_2$ resonance to set constraints on the family age.
  Like the ${\nu}_{6}$ and $z_1$ secular resonances, the $z_2$ resonance is
characterized by one stable equilibrium point at $\sigma = 180^{\circ}$ in the
$z_2$ resonance plane $(\sigma, \frac{d\sigma}{dt})$, where $\sigma$ is the
resonant angle of the $z_2$ resonance. Diffusion in this plane occurs on
timescales of $\simeq 12$ My, which sets a lower limit on the Erigone family
age. Finally, the minimum time needed to reach a steady-state population of
$z_2$ librators is about 90 My, which allows to impose another, independent
constraint on the group age.
