So many, in fact, that it was decided that some thin layers of tooth enamel could be sliced from the teeth of the animals to find out from their chemistry something about the long-lost food web.
The results of the study by Kohn, his student Moriah McKay and South Caroline State Museum curator James Knight appear in the August issue of the journal
Geology.
The tooth enamel of the carnivores and the many large herbivores from the Camelot dig was analyzed to find out how much carbon-13 they contained. That isotope is an important clue to diet because it is more abundant in some plants — the bottom of the food chain — than others.
Open grasslands, for instance, are loaded with plants known to take up lots of carbon-13. On the other extreme are forest plants, which are the lowest in carbon-13. The differences come from different types of photosynthesis used by the plants.
"The carnivore tooth enamel composition is almost exactly what it eats," says Kohn. So a predator that eats forest herbivores, has tooth enamel that reflects lower amounts of carbon-13. At Camelot this isotopic clue reveals some expected and unexpected lifestyles among the ancient carnivores, said Kohn.
