Aside from the obvious being stated in the History of the Lizardmen, what was the world like before the Old Ones came?
It is said that the world was covered in thick sheets of ice but is it possible that either A) It was covered in ice in the poles and that in the equator, it was warmer and more tropical?
Or that B) The Ice Age that the world was in when the Old Ones came was just the most recent the world has been through before the Old Ones. That could mean that the world before the Old Ones has gone through a changing shift from Ice Age to Tropical Paradise that occurs once every millennia or something. This is idea is similar to that of the world of Game of Thrones where seasons there can span for years.
Would of these scenarios possible in the Warhammer world before the Old Ones?