When is the eruption of Vesuvius now thought to have taken place?

What is a 'cena'?

What are sonic anaphones?

When did the dinosaurs become extinct?

What is a 'hydria'?

What is a half-life?

What is the etymology of the word 'volcano'?

According to the fossil record, how regularly have mass extinctions happened on Earth?

What constitutes a mass extinction?

What is radiometric dating?