extinct (suomeksi)

hävinnyt (a)
sukupuuttoon kuollut (a: having died out / of a species)
sammunut (a: tulivuori / extinguished, no longer alight (of fire, candles etc.) / no longer erupting)
kadonnut (a: no longer used; obsolete, discontinued)
poistunut (a: no longer used; obsolete, discontinued)