Strength in Numbers: Red Galaxies Bolster the Cosmic Star Formation Rate Density at z ≳ 3

A comprehensive account of the cosmic star-formation history demands an accurate census of dust-enshrouded star formation over cosmic time. We provide strong new constraints from a large sample of 777 red galaxies, selected based on their dust-reddened rest-frame UV-optical emission. This sample spans 1 < z < 8 and is selected from PRIMER JWST NIRCam and HST COSMOS optical data. The SEDs indicate that these galaxies are star-forming, with median SFR ~ 40 Myr⁻¹ and stellar mass log (M*/ M) = 10.3+0.6-0.8; each exceeds the corresponding medians of the full JWST-detected population by over two dex. Our sample shows that red galaxies dominate the high-mass end, comprising 72 % of galaxies with log (M/M⊙) > 10 at z = 3.3, and rising to 91 % by z ~ 7. Crucially, the number density of massive red star-forming galaxies at z ~ 6 is sufficient to explain the abundance of quiescent galaxies at z > 3, consistent with quenching within a ~1Gyr interval from z ~ 6 to z ~ 3. This abundance yields a major contribution to the cosmic star-formation rate density: at z ~ 4, red galaxies provide ρ SFR = 3.9+0.6-0.5 × 10⁻² M yr⁻¹Mpc⁻³, and at z ~ 5 they supply nearly 40 % of the total ρSFR. This contribution exceeds that of bright sub(mm)-selected dusty star-forming galaxies by more than an order of magnitude. Future, deeper, and wider ALMA surveys will further strengthen and extend these results in quantifying the role of dust-obscured activity in ρSFR at high redshifts.