To me it seems that the warm blooded dinosaurs replaced advanced mammal ancestors that were warm blooded, also.
“Heart is what drives us and determines our fate. That is what I need for my characters in my books: a passionate heart. I need mavericks, dissidents, adventurers, outsiders and rebels, who ask questions, bend the rules and take risks.”
“Animals, whom we have made our slaves, we do not like to consider our equal.”