Quark-Gluon Plasma Epoch
All elementary particles appear. Quarks, leptons, bosons, antimatter. Too hot for particles to bind. Pure particle soup.
At first, just after the Big Bang, there were no particles. Everything was pure energy in a hot, dense soup. As the universe cooled slightly, energy turned into matter. The first 'players' showed up. In that early moment, many elementary particles existed; only a few mattered for later atom formation.