Fraction of mass from the ‘born in KCDs’ stars contributing to the pseudo-bulge at redshift |$z = 4.4$| (dark-green dashed line), with the solid purple line illustrating the overall trend. The blue crosses indicate the fraction of the total mass of the pseudo-bulge identified at |$z = 4.4$| originated from each primordial KCD. The light-green dot-dashed line shows the cumulative mass fraction of the pseudo-bulge at |$z = 4.4$|⁠, which indicates the total amount of the pseudo-bulge’s mass that has been formed from all primordial KCDs at each redshift. Additionally, the three grey dashed vertical lines mark peaks in SF at |$z \le 6$| as identified by Tamfal et al. (2022).