3 The Importance of Dry and Mixed Mergers for Early - Type Galaxy Formation

We use semi-analytical modelling techniques to investigate the progenitor morphologies of present day ellipticals. We find that, independent of the environment , the fraction of mergers of bulge dominated galaxies (early-types) increases with time. The last major merger of bright present day ellipticals with M B −21 is preferentially between bulge dominated galaxies, while those with M B ∼ −20 have mainly experienced last major mergers between a bulge dominated and a disk dominated galaxy. Independent of specific model assumptions, more than 50% of present day elliptical in clusters with M B −18 had last major mergers which are not of spirals as usually expected within the standard merger scenario.