About This Project

While doing chemical analysis of tooth enamel to reconstruct ancient environments, paleontologists have become over-reliant on the mammalian third molar (M3 or wisdom tooth). The problem with this is that the third-molar is rarely found in younger mammals' jaws, whereas young animals constitute much of the fossil record. Here, we seek to test the viability of using incisors (which are much more common) instead of the M3 as a new, more abundant resource to reconstruct the Earth's past.

Ask the Scientists

What is the context of this research?

The widespread dependence on third-molars (or "wisdom teeth," abbreviated M3) in environmental studies, is a limitation that we find concerning. M3s are ideal because they are generally large enough for multiple analyses and also form after milk-weaning (see Bryant et al., 1996 and Hoppe et al, 2004 and 2005). The assumption that the other tooth positions may contain a "milk signal" is largely untested, and there is some evidence that it is relatively minor (see Wang et al., 2008). We believe that the narrow focus on M3s as the sole means to understanding ancient environment is unnecessarily limiting. With this project, we will explore viable alternatives to study of M3, improving the likelihood of making meaningful environmental interpretations with a broader range of potential samples.

What is the significance of this project?

Third molars are only found in mammals aged well past adolescence and into sexual maturity. Many mammals die and fossilize before the third molar even begins to form. We believe that other tooth positions, especially incisors, may yield equally accurate findings as would a third molar, making available a much broader suite of fossils for study. Materially, this will drive down the costs of having to find and analyze jaws (as one won't need to worry about finding jaws with very specific teeth), as well as save time for those researchers. This will also make it possible to conduct research with specimens in lower demand for other types of paleontological research. In short, using teeth other than the M3 will result in more research with less risk.

What are the goals of the project?

The goal of this project is to explore the viability of teeth that are not third molars for conducting chemical analysis to better understand past environments

We will solicit and crowdsource our fossilized jaws from connections in the field as well as strangers. We plan on obtaining fossils in throughout the United States, and hopefully as far away as Australia where we can study the implications of tooth position in not just the jaws of placental mammals, but those of marsupials as well. Recent studies show that teeth in the jaws of rodents are particularly sensitive to environmental changes.

Through analysis of multiple teeth from a single jaw, we can confidently show whether other tooth positions provide equivalent interpretations as the most commonly used third molar.