After 400,000 years ago, they aren't called Homo erectus anymore, they're called archaic Homo sapiens. (Or just Homo sapiens, if you call the subgroup that arose about 120,000 years ago Homo sapiens sapiens. Whatever floats your boat.) They didn't so much go extinct as they changed. They overlap and intergrade with both Neanderthals and their contemporaries, modern Homo sapiens.
I've posted and re-posted the hominid skulls from the periods from 400,000 to 100,000 years ago. We do not lack for ancestors.
Even you.
How funny. You cannot find the proof can you? Nothing is called archaic anything (as I have already told you) they are always called by the species name (I am talking among scientists of course, not evolutionists). Also a species name does not change just because of the date of the find. That is not science. Science changes the species name when the characteristics change. However, you are still bantering words instead of doing what you should have done when I questioned you first on this: