On the proper symmetry theoretical formulation of the theory of Lorentz covariant, or ‘relativistic’, quantum particle dynamics, we illustrate the inadequacy of the Poincare symmetry for the purpose and present a fully conceptually consistent formulation from a larger symmetry which also admits a noncommutative geometric interpretation as an exact analog of that of the standard quantum mechanics as its ‘nonrelativistic’ limit, to be retrieved from a symmetry contraction procedure. Our approach emphasizes how such a formulation gives essentially all aspects of the theory from a full representation picture, including the dynamics from the natural symplectic geometry.