  We report an observation of a dynamical super Efimovian expansion in a
two-component strongly interacting Fermi gas by engineering time dependent
external harmonic trap frequencies. When trap frequency is followed as
$[1/4t^2+1/t^2\lambda\log(t/t_*)]^{1/2}$, where $t_*$ and $\lambda$ are two
control parameters, and the change is faster than a critical value, the
expansion of such the quantum gas shows a novel dynamics due to its spatial and
dynamical scaling symmetry. A clear double-log periodicity, which is a hallmark
of the super Efimov effect, is emergent for the cloud size in the expansion.
The universality of such scaling dynamics is verified both in the
non-interacting limit and in the unitarity limit. Observing super-Efmovian
evolution represents a paradigm in probing universal properties and allows in a
new way to study many-body nonequilibrium dynamics with experiments.
