  We address the emergent quantum critical phenomena for (pseudo)spin-3/2
birefringent fermions, featuring two effective Fermi velocities, when they
reside close to itinerant Mott transitions realized through spontaneous
symmetry breaking and triggered by strong local or Hubbardlike repulsive
interactions. Irrespective of the nature of the mass orderings that produce
fully gapped quasiparticle spectra in the ordered phase, which otherwise can be
grouped into three classes, the system always possesses a \emph{unique}
terminal velocity near the corresponding quantum critical point. The associated
critical regime accommodates a relativistic non-Fermi liquid of strongly
coupled collective bosonic and spin-1/2 Dirac excitations with vanishing weight
of the quasiparticle pole. These conclusions are also operative near
superconducting critical points. Therefore, relativistic non-Fermi liquid
possibly constitutes a robust superuniversal description for the entire family
of strongly correlated arbitrary half-integer spin Dirac materials.
