New Members of the Scorpius Centaurus Complex and Ages of its   sub-regions
  We have spectroscopically identified about 100 G-, K- and M-type members of the Scorpius Centaurus complex. To deduce the age of these young stars we compare their Li $\lambda$6708 absorption line strengths against those of stars in the TW Hydrae association and $\beta$ Pictoris moving group. These line strengths indicate that Sco-Cen stars are younger than $\beta$ Pic stars whose ages of ~12 Myr have previously been derived from a kinematic traceback analysis. Our derived age,~10Myr, for stars in the LCC and UCL subgroups of ScoCen is younger than previously published ages based on the moving cluster method and upper main sequence fitting. The discrepant ages are likely due to an incorrect (or lack of) cross-calibration between model-dependent and model-independent age-dating methods. 
Inseok Song, Ben Zuckerman, and Mike Bessell
astro-ph.SR