A horological resonator mechanism, including a structure carrying, via a flexible suspension, an anchor unit from which is suspended an inertial element oscillating about a pivot axis extending in a first direction Z, in a first degree of rotational freedom RZ, under the effect of the return forces of a flexure pivot including longitudinal elastic strips, each fixed to the inertial element and to the anchor unit, the flexible suspension allowing the anchor unit to move in five degrees of freedom, this resonator is a composite assembly made of at least two different materials, on the one hand for the flexure pivot, and on the other hand for the flexible suspension.