Mass–radius distribution of known exoplanets (and brown dwarfs) with radii derived from primary transits and masses derived from RVs (562 planets and companions, excluding upper mass limits). Stellar ages are taken from Exoplanet.eu and are color-coded. Stars with ages < 50 Myr (all green) are shown as larger circles. Stars without known ages are marked as empty circles. The bright green triangle denotes HD 114082 b. Error bars, where known, are smaller than the symbol sizes. Thick colored lines mark isochrones for ages of 10–20 Myr from Fortney et al. (2008) for hot-start models (blue) and cold-start models (green). The dashed black line shows the isochrone from the combined COND (Baraffe et al. 2003) and DUSTY (Chabrier et al. 2000) models.