Density distribution considering only particles trapped in resonances with Mars in a Martian single planet system in a fixed reference frame at three different planetary phases for β = 0.01. To identify trapped particles, their semi-major axis evolution was analysed. Only when the semi-major axis hovered about a constant value a particle was considered trapped and only then it was accounted for in the density distribution. As with the previous density plots, the density is normalised to the surface density arising under the absence of planets. The low density as well as the different geometry of these resonant features makes them inadequate as to solely account for the overall density variations produced by Mars (Fig. 8), indicating a formation mechanism other than resonant trapping.