This handsome devil is Bunostegos akokanensis, a large reptile that lived in northern Niger 266-252 million years ago. “Imagine a cow-sized, plant-eating reptile with a knobby skull and bony armor down its back,” writes University of Washington biologist Linda A. Tsuji. The image is an artist's rendering based on fossils recently unearthed by Tsuji and her colleagues. (National Geographic)