When a particle distributes at a rate that deviates from the classical Brownian motion model, fractional space derivatives have been used to simulate anomalous diffusion or dispersion. When a fractional derivative substitutes the second-order derivative in a diffusion or dispersion model, amplified diffusion occurs (named super-diffusion). The proposed approach in this paper allows seeing the physical background of the newly defined Caputo space-time-fractional derivative and indicates that the order of convergence to approximate such equations has increased.