Caries in Pliocene rodents

At the site of Węże 2 near Działoszyn in Łódź Voivodeship numerous remains of mammals and other vertebrates dating from the Pliocene (over 2.5 million years ago) were found. A tooth of the dormouse Glis sackdillingensis is affected by caries that was developing during the animal’s life. Moreover, examination of the cavity under a scanning electron microscope revealed the presence of fossilized microorganisms similar to modern cariogenic bacteria. Supposedly the specimen contains signs of disease together with remains of pathogens responsible for its development. This is probably the only such case thus far described in palaeontological literature.

Figure: fossilized remains of Pliocene pathogenic bacteria (D–F) were found in a caries-affected tooth (A–C) of an extinct rodent.