  We present neutron scattering results on the magnetic excitations in the
spinel compounds Li$_x$[Mn$_{1.96}$Li$_{0.04}$]O$_4$ (x= 0.2, 0.6, 0.8, 1.0).
We show that the dominant excitations below T ~ 70 K are determined by clusters
of Mn^4+ ions, and that these excitations mimic the E/T-scaling found in
quantum critical systems that also harbor magnetic clusters, such as
CeRu$_{0.5}$Fe$_{1.5}$Ge$_2$. We argue that our results for this classical
spinel compound show that the unusual response at low temperatures as observed
in quantum critical systems is (at least) partially the result of the
fragmentation of the magnetic lattice into smaller units. This fragmentation in
quantum critical systems is the direct and unavoidable result of intrinsic
disorder.
