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Desert Diary


Beautiful smile? Unless you're one of the really lucky ones, you've paid dearly for it. Brushing, flossing, mouthwashes, dentists—major efforts to keep our teeth from rotting away. It's ironic, then, that once an animal is dead, the teeth often are preserved long after other parts are dust. Here's one time when paleontologists who work with mammals really luck out, because teeth tell all sorts of tales.

A molar with low, rounded cusps? Probably an omnivore like humans, bears, and pigs, eating almost anything. An animal with a pair of upper and lower cheek teeth fitting together like the blades of scissors? A carnivore, built to slice meat. A tooth surface with complex patterns of enamel and dentine? An herbivore. Peg-like teeth? How about a fish-eater like a porpoise? Broad flat molars? Sea otter!

So well do the teeth fit the animal, that we can be quite confident about the diet of long-extinct mammals, even when teeth are all we have. Now if only our teeth would preserve as well as fossils while we're alive!
pen and ink

Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.

upper dentition of bobcat

The business end of a Bobcat (Lynx rufus). The teeth at the front are used for nipping and removing small pieces of meat. The enlarged canine teeth both hold and wound prey. The last two teeth visible are adapted for slicing (not visible is a small, posterior peg tooth that apparently acts as a stopper to prevent the slicing teeth of the lower jaw from damaging the cat itself.



Carroll, R. L. 1988. Vertebrate paleontology and evolution. W. H. Freeman and Co., New York, 698 pp.

Dahlberg, A. A. (ed.). 1971. Dental morphology and evolution. University of Chicago Press, Chicago, 350 pp.

Hillson, S. 1986. Teeth. Cambridge manuals in archaeology. Cambridge University Press, Cambridge, 376 pp.

Vaughn, T. A. 1986. Mammalogy. Saunders College Publishing, third ed., Philadelphia, 576 pp.

Web Resources

University of Michigan Museum of Zoology.