  In this work we study the effects of collapse and revival as well as {\it
Zitterbewegung} (ZB) phenomenon, for the relativistic electron wave packets,
which are a superposition of the states with quantum numbers sharply peaked
around some level $n_0$ of the order of few tens. The probability densities as
well as average velocities of the packet center and the average spin components
were calculated analytically and visualized. Our computations demonstrate that
due to dephasing of the states for times larger than the cyclotron period the
initial wave packet (which includes the states with the positive energy only)
loses the spatial localization so that the evolution can no longer be described
classically. However, at the half-revival time $t=T_R/2$ its reshaping takes
place firstly. The behavior of the wave packet containing the states of both
energy bands (with $E_n>0$ and $E_n<0$) is more complicated. At short times of
a few classical periods such packet splits into two parts which rotate with
cyclotron frequency in the opposite directions and meet each other every
one-half of the cyclotron period. At these moments their wave functions have
significant overlap that leads to ZB. At the time of fractional revival each of
two sub-packets is decomposed into few packets-fractions. However, at $t=T_R$
each of the two sub-packets (with positive or negative energy) restores at
various points of the cyclotron orbit, that makes it impossible reshaping of
initial wave packet entirely unlike the wave packet which consists of states
with energies $E_n>0$ only. Obtained results can be useful for the description
of electromagnetic radiation and absorption in relativistic plasma on
astrophysics objects, where super high magnetic field has the value of the
order $10^8-10^9$T, as well as for interpretation of experiments with trapped
ions.
