Proper eccentricity e_p vs. proper inclination sin I_p distribution of a simulated family linked to (65) Cybele. The dynamical evolution of the family was computed from 0 to 4 Gyr. Left panels: large family made of 3000 multi-kilometre-sized bodies ejected from (65) Cybele. Ten clones of Cybele itself were also produced (yellow). The colours and symbol sizes correspond to the logarithm of the diameter of the objects. Right panels: smaller subset of 300 bodies drawn from the large family. The axis ranges correspond 1:1 to Fig. 5. After 1 or 2 Gyr, depending on the initial population, the family is no longer observable.