Top panel: MS stellar density map showing the locations of nine young (< 1 Gyr) star clusters (blue circles) associated with the shell feature, defined here spatially by the red polygon. Bottom panel: combined CMD of the nine young star clusters, showing their collective compatibility with a single age of ∼160 Myr. We overplot a ∼160 Myr PARSEC isochrone (log(age/yr) = 8.2, Z = 0.002, A_V = 0.25 mag, (m-M) = 18.96) for reference.