Distribution of the time (x-axis) and stellar mass ratio (μ, y-axis) of the mergers for galaxies in each subsample: mostly-disc (left), intermediate (middle), and spheroid-dominated (right). Merger patterns are different across the galaxy types. The mostly-disc objects avoid mergers in the past ∼4 Gyrs. Merging also seems common for spheroid-dominated galaxies at very early times (≥9 Gyr ago).