Luckily, such ideas about race are extinct in current sociological theory.
Indeed the very fact that the English spelling system writes in there as two words but therein as one word might be taken as suggest- ing that only the former is a productive syntactic construction in Modern English, the latter being a now extinct construction which has left behind a few fossil remnants in the form of compound words such as thereby.
The dinosaurs have been extinct for millions of years.
Most of the volcanos on this island are now extinct.