rex could chip a tooth or get one stuck in prey, and just replace it. ![]() "Each tooth - relatively speaking - doesn't have as much value to the animal as in mammals," Tseng said. Mammals typically grow a set of baby teeth followed by a set of adult teeth, whereas reptiles - and likely many, if not all, dinosaurs - replace individual teeth throughout their lifetimes, scientists have found. In reptile teeth, the enamel grows in one direction, creating a different type of structure that may not retain water as effectively - potentially making their teeth more likely to chip or crack, Tseng suggested.īut for reptiles - and theropod dinosaurs - damaging or losing a tooth simply isn't as big a deal as it would be for a mammal, Tseng added. He explained that when mammal teeth grow, the enamel emerges from the root area and "races outward in all directions," creating a 3D shape that may be better at keeping water inside. "Mammalian teeth are prismatic - they have a crisscrossing structure," Tseng told Live Science. A mammal's tooth structure is actually quite different from a reptile's, said Zhijie Jack Tseng, a paleontologist who studies bite-force biomechanics in extinct carnivores at the American Museum of Natural History in New York City. Wouldn't their teeth have been vulnerable to serious drying out, too? What about elephants?īut crocodiles aren't the only animals with exposed teeth - elephants, for instance, have exposed teeth as well, and many extinct saber-toothed predators had very long canines that were also exposed when their mouths were closed. ![]() But land-dwelling theropods' large teeth - which are known to have enamel - could have been compromised by perpetual exposure, and likely needed to be covered by lips in order to stay moist, Reisz said in the presentation. ![]() Without lips to keep moisture in and prevent the teeth from drying out, the tough enamel would become brittle and more prone to damage and wear, Reisz told Live Science.Ĭrocodiles live in watery environments and would rely on their habitat to keep exposed teeth hydrated. The hard enamel of animals' teeth has low water content, and is typically kept hydrated by saliva.
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