A nose for combat.

A nose for combat

Sometimes injuries and disease can prove helpful, especially when they offer researchers a glimpse into the lifestyle of a long-extinct animal. Take the mosasaur, a giant aquatic lizard from the dinosaur era. While studying about four dozen mosasaur jaws and skulls, a pair of paleontologists noticed a pattern of injuries. Gordon L. Bell Jr. of the University of Texas at Austin and James Lamb of the Red Mountain Museum in Birmingham, Ala., found that about half the specimens showed evidence of healed gash woulds on their snouts. In some cases, specimens sported several regularly spaced wounds running in a line along the outside of the jaw.

Though initially puzzled, Bell and Lamb now offer a theory to explain the wounds. They suggests mosasaurs sometimes grappled each other's noses, much as some modern alligators and lizards do. Observers have noticed that alligators in a confrontation will sometimes lock snouts and twist about, Bell says.

He and Lamb propose this same style of combat could explain the grooved wounds along the mosasaur jaws. Because the long, thin animals would have attacked head-on, most battles would have sent both individuals spinning and so would have rarely proved deadly -- a concept that would explain why so many mosasaurs show evidence of nonfatal wounds. The researchers plan to check their hypothesis by looking at other collections of mosasaur fossils. If the animals did indeed grapple, that behavior suggests they were much more territorial than previously suspected, Bell says.