NORTH AMERICAN BULLFROG
The bullfrog's skull is fragile, partly due to the large holes for the eyes (which are retracted during swallowing, possibly to help push food back toward the esophagus). Its mouth is immensely out of proportion to provide the best chance of netting a meal. The mandible is toothless--frogs tend to swallow prey whole--but the upper jaw has rows of tiny teeth used to grasp.
Reprinted from Skulls, by permission of Black Dog & Leventhal Publishers. Copyright © 2012