Ice Age coyotes were supersized compared to coyotes today, fossil study reveals. National Evolutionary Synthesis Center, February 27, 2012. Coyotes today are pint-sized compared to their Ice Age counterparts, finds a new fossil study. Between 11,500 and 10,000 years ago — a mere blink of an eye in geologic terms — coyotes shrunk to their present size. The sudden shrinkage was most likely a response to dwindling food supply and changing interactions with competitors, rather than warming climate, researchers say. Picked up by the Huffington Post, Wired, MSNBC, and Science Magazine.