A mechanical masticator, or “chewing robot”, has been developed that can provide a tie between tooth wear and extinct animal’s lifespan, by rapidly chewing palaeodiet food.
While the types of food an extinct species ate millions of years ago seems like one of those things that would be difficult to know, palaeontologists have had to come up with some methods to probe a bit deeper. One of these methods is evaluating tooth microwear which can help to reconstruct and analyse dietary patterns of human ancestors and animals.
However, wear measurements are complicated, expensive and time-consuming and the majority of systems don’t allow 3D simulation of masticating movements. As microwear is a common proxy for diets of extinct species, researchers from University of Helsinki in Finland have developed a fast and cost-efficient mechanical masticator.
Their chewing robot comes together with a few 3D-printed parts and is based on real horse teeth. This way, it enables the continuous simulated chewing of 100 000 chewing cycles on teeth that resemble wear in specimens collected from nature. Critically, the study of tooth wear can be carried out in a controlled laboratory environment and it can help to track the diet of our ancient animals by analysing the wear rate on their teeth.
Tooth microwear is the pits and scratches on teeth, which are left as a result of eating and their findings highlight that absolute wear of these pits and scratches increased with plant diet abrasiveness. Additionally, their results demonstrate that all diets cause microscopic wear features to the tooth surface, regardless of the diet. This contradicts some of the previous research on the same topic, so further research is required.
Most mammals are in serious trouble when their teeth wear out. As dental wear gets beyond a certain point, efficiency begins to drop. Aleksis's chewing robot can help us understand feeding and diet in extinct organisms, and therefore how they fit within their immediate environment and their world.
However, this method isn’t foolproof. Dental microwear features can result from many factors besides food, including the presence of environmental grit, and behaviours like grooming, gnawing on non-food items, or tooth grinding. The interplay between food, jaw mechanics, and tooth wear continues to be an active area of research.
“If you eat soft food, let’s say tree leaves, with horse teeth, you can live up to 600 years if it would be only teeth that determined it,” concluded Aleksis Karme, who came up with the horsey chewing robot that lives on a palaeodiet.