Scientists have found that a type of ancient man, called Neanderthals, cooked and ate plants as well as meat.
They studied Neanderthal remains, and found little bits of cooked plants stuck between their fossilised teeth!
It's an important discovery, as it shows that ancient man ate a varied diet - just like us.
Scientists previously thought ancient man only ate meat. It's hoped this new discovery will help them understand the way in which cave men developed.