Disentangling sources of anomalous diffusion.

We show that some important properties of subdiffusion of unknown origin (including ones of mixed origins) can be easily assessed when finding the "fundamental moment" of the corresponding random process, i.e., the one which is additive in time. In subordinated processes, the index of the fundamental moment is inherited from the parent process and its time dependence from the leading one. In models of a particle's motion in disordered potentials, the index is governed by the structural part of the disorder while the time dependence is given by its energetic part.