New Study Ties Tooth Wear in Fossils to Diet, Validating Decades of Research

Russell Cothren

Peter Ungar, Distinguished Professor and chair of the Department of Anthropology, and Ryan Tian, professor of chemistry

FAYETTEVILLE, Ark. — A team of researchers has validated data and found a new model for paleontologists to use to track the diet of our ancient ancestors and animals by analyzing the wear on their teeth.

Dental wear is among the top techniques scientists use to reconstruct and analyze dietary patterns of human ancestors and animals. Researchers recently questioned the validity of tooth-wear analysis, however, stating that environmental elements such as grit on food was likely responsible for wear.

“This challenge has led paleontologists to question decades of results,” said Peter Ungar, Distinguished Professor and chair of the University of Arkansas Department of Anthropology. “Our findings validate the use of tooth wear for understanding diet of fossil animals. What does this tell us about diet? That habitat doesn’t necessarily skew dental wear data.”

Ungar worked with Ryan Tian, U of A professor of chemistry, and researchers at the Tribology Research Institute at Southwest Jiaotong University in China to verify the tie between tooth wear and diet.

The Proceedings of the National Academy of Sciences published the findings this month.

“We found that materials softer than enamel can wear teeth,” Ungar said. “This allowed us to develop a whole new way to model tooth wear.”.

Ungar explained that enamel is made up of particles bonded together by a protein glue. He and the team found through experiments that as chewing occurs, those bonds break and tiny enamel particles break away from teeth.

This finding validates the long-held premise that tooth wear can be related to specific types of diets and environments.

For example, scratches on fossilized teeth indicate a shearing chewing motion used with tougher meats and plant-based diets. Pits in teeth indicate a hard and brittle natural diet such as animal bones or nuts.

“We determined that microwear is not just about grit in the environment,” Ungar said. “There certainly can be a diet component to it.”

The team’s discovery opens the door to study the properties of other materials.

“What Mother Nature does in tooth enamel encourages us to revisit known theories in nanocrystal science, polymer, composite, biomineralization, self-assembly and surface science,” Tian said.

About the University of Arkansas: The University of Arkansas provides an internationally competitive education for undergraduate and graduate students in more than 200 academic programs. The university contributes new knowledge, economic development, basic and applied research, and creative activity while also providing service to academic and professional disciplines. The Carnegie Foundation classifies the University of Arkansas among only 2 percent of universities in America that have the highest level of research activity. U.S. News & World Report ranks the University of Arkansas among its top American public research universities. Founded in 1871, the University of Arkansas comprises 10 colleges and schools and maintains a low student-to-faculty ratio that promotes personal attention and close mentoring.