All fossil mammal teeth look the same.

Paleontologists have that strange ability to see things that others don't or can't see. Nowhere is this case best illustrating in mammal teeth. Each bump and grove indicates a unique species or genus in the fossil record. Skilled paleontologists can identify a species of any mammal that lived, just by looking at several of its teeth. This amazing diversity in mammal teeth hides the fact that overall mammalian teeth are rather conservative in their general form and particularly in their function. They all mainly serve to break down and chew food. So undoubtedly teeth also reveal a mammal's diet. Paleontologists are left with a quandary. How much does diet and how much does taxonomy contribute to a tooth's form? Or presented in a different way, if you analysis a number of fossil mammal teeth for similarities, do these similarities reflect similar diets OR similar relationships. I've often questioned the utility of using teeth in systematic studies of taxonomic relationships because you may end up with groupings that reflect similar diets instead. In a recent article in Nature Alistair R. Evans and colleagues present a study of computer generated models of modern mammal teeth using a high-resolution laser scanner. The constructed models were analyzed for similarities. The researchers conclude that the surface complexity of tooth crowns directly reflects the foods they consume, and that there are high-levels of similarity in the tooth shape between widely divergent diets, such as carnivores and herbivores.


Evans, A., Wilson, G.P., Fortelius, M. and Jernvall, J., 2007. High-level similarity of dentitions in carnivorans and rodents. Nature 445, 78-81 (4 January 2007) | doi:10.1038/nature05433.