  Dynamics of attractive ultra-cold bosonic clouds in one dimension are studied
by solving the many-particle time-dependent Schr\"odinger equation. The
initially coherent wave-packet can dynamically dissociate into two parts when
its energy exceeds a threshold value. Noticeably, the time-dependent
Gross-Pitaevskii theory applied to the same initial state does not show up the
splitting. We call the split object {\it fragmenton}. It possesses remarkable
properties: (1) it is two-fold fragmented, i.e., not coherent; (2) it is
dynamically stable, i.e., it propagates almost without dispersion; (3) it is
delocalized, i.e., the two dissociated parts still communicate with one
another. A simple static model predicts the existence of fragmented states
which are responsible for formation and dynamics of fragmentons.
