Top: luminosity-weighted SSP α-element abundance vs. effective velocity dispersion of the ATLAS^3D galaxies. The dashed black line is the best-fit relation from McDermid et al. (2015, see their Table 5, relation i). Bottom: α-element abundance corrected for the σ_e dependance (by subtracting the values as given by the dashed line in the top panel) vs. the SSP age. Both SSP ages and [α/Fe] values are taken from McDermid et al. (2015), which also show that very old SSP ages are consistent with the fiducial age of the Universe (Planck Collaboration XIII 2016) when measurement errors and SSP mode uncertainties are taken into account. In both panels the symbols are the same and as described in the legend. Core-less slow rotators have a range of SSP ages, while core slow rotators as well as all but one core fast rotators are older than 10 Gyr.