BOB HIRSHON (host):
Prehistoric dental disease…I’m Bob Hirshon and this is Science Update.
The world’s oldest known dental infection has been diagnosed, 275 million years postmortem, in the fossilized jaw of an ancient reptile called Labidosaurus. University of Toronto biologist Robert Reisz and his colleagues made the call.
ROBERT REISZ (University of Toronto):
There were three holes where teeth should have been, and there was also a gap in the jaw edge, where we were able to reconstruct that pus must have exited, because this animal probably had an abscess.
Reisz notes that Labidosaurus and its relatives were among the earliest land animals to have permanent teeth like ours, rather than semi-disposable ones that were replaced throughout life. Firmly implanted teeth gave them a stronger bite that helped them broaden their diet. The downside is that it made them susceptible to tooth decay – but overall, the trade paid off. I’m Bob Hirshon, for AAAS, the science society.