65 Million Years Ago

Science fiction. It is said that 65 million years ago, a higher intelligent race from Procyon (the first-class star in Canis Minor) and a higher intelligent race from another universe came to the earth at almost the same time. In order to fight for the earth's resources, they started a war. This war led to nuclear winter and caused the extinction of most of the earth's creatures, including dinosaurs... (This book is a prequel to my previous work "Frozen World Outpost")