Researchers Find The Cause Of The Oldest Case Of Cavities In Prehistoric Mammals

JAKARTA - The earliest known case of cavities in mammals has been found in a squirrel-sized species that lived 54 million years ago. These animals are known to eat sweet fruits.

A fossil specimen of the prehistoric tree-dwelling primate, Microsyops latidens, was analyzed by researchers from the University of Toronto Scarborough. They found that 7.5 percent of all the fossils they studied had cavities, with some layers containing greater frequency than others.

This suggests that the Microsyops latidens diet varied over time between foods with higher and lower sugar content. The study was conducted by anthropologists Keegan Selig and Mary Silcox of the University of Toronto Scarborough.

"Tooth decay or caries is a common disease among modern humans, affecting almost every adult", the two wrote in their paper.

"Carious frequency has been used to study dietary changes in humans over time, based on the inferred relationship between caries incidence and carbohydrate-rich diets", they added.

“However, this disease is not unique to our species. Among non-human primates, there is also a variation in caries frequency associated with diet", Selig said. These metrics can provide a mechanism for studying diet in a broader context, and across geological time.

In their study, the researchers analyzed a total of 1.030 individual fossil teeth and jaw sections excavated in the Southern Bighorn Basin of Wyoming, in the US. The team found that 77 specimens included cavities, which they thought were likely caused by a diet high in fruit or other sugar-rich foods.

However, by dating the fossils based on the age of the sediments in which they were deposited, the pair determined that the frequency of the voids varied over time, with the least being found in the oldest and youngest specimens.

This indicates that the diet of Microsyops latidens changed over time between foods with different levels of sugar content. This may be in response to changes in vegetation growth and food availability caused by current climate fluctuations.

"Microsyops latidens may rely on food sources that are higher in sugar, and therefore more cariogenic (likely to cause tooth decay), during periods of climate change", the researchers wrote in their paper.

“This, they explained, could be a result of increased competition for limited food sources, or changes in available food sources. This, in turn, may have led to an increase in caries frequency", the study said.

"As more paleoclimate data becomes available, it is likely that we will see evidence of further climate change during this period, which may have affected the food sources available for M. latidens", the researchers add.