A special post from Alison Boyer whose research encompasses birds and body size evolution. Penguins are remarkable divers, capable of diving to depths exceeding 200m. The largest penguin species, Emperor penguins (Aptenodytes forsteri), have been recorded diving to 535m and can hold their breath for 15 minutes while actively swimming. Generally, small-bodied vertebrates are limited . . . → Read More: Useless Wings But Better Lungs