An undated handout picture released on April 18, 2011 shows arrows pointing to a reconstruction of the site of an abscess and where the teeth fell out of a Labidosaurus hamatus, a fat-headed, omnivorous reptile about 75 centimeters long. Missing teeth and the decayed jawbone of a 275-million year old reptile have pushed back the earliest evidence of tooth decay some 200 million years, according to a study published on April 18, 2011. – AFP Photo

PARIS: Missing teeth and the decayed jawbone of a 275-million year old reptile have pushed back the earliest evidence of tooth decay some 200 million years, according to a study published Tuesday.

The new find also highlights the downside of the evolutionary shift from loosely-fitted teeth that fall out but grow back to having a single set of permanent chompers, a drawback shared by adult humans, the researchers said.

Labidosaurus hamatus -- a fat-headed, omnivorous reptile about 75 centimeters long -- adapted over millions of years to life on land rather than the watery marshes of its amphibious forebear.

It's stouter legs and armour-like skin were better adapted to running and warding off predators.

And its non-replaceable teeth, deeply anchored in its jaw, were better suited for eating fibrous plants and stems, alongside its more ancient diet of flying and crawling insects.

But having fixed-for-lifetime dentition made hamatus vulnerable to the same type of bacterial decay that plague humans and keep approximately two million dentists around the world employed.

“Our findings allow us to speculate that our own human system of having just two sets of teeth, baby and permanent -- although of obvious advantage because if its ability to chew and process many different food stuffs -- is more susceptible to infection,” the authors concluded.

Researchers led by Robert Reisz, a professor at the University of Toronto at Mississauga, analysed an “exquisitely preserved” jaw found near Coffee Creek, Texas using CT-scan technology.

They found evidence of massive infection, likely resulting in the loss of several teeth and bone destruction in the jaw in the form of an abscess.

The study was published in the peer-reviewed journal The Nature of Science.

Opinion

Poisoning minds
23 Jan 2021

Poisoning minds

ICS cadets were raised on James Mill’s notorious work.
The fog of Broadsheet
23 Jan 2021

The fog of Broadsheet

How can the government pump credibility into an official probe when it has already declared its own political verdict?
Cheating on online exams
23 Jan 2021

Cheating on online exams

The difficulty of preventing online cheating and low ethical standards means that these days most students cheat.
Language mess
Updated 22 Jan 2021

Language mess

Our policy confuses the medium-of-instruction debate with the language-acquisition debate.

Editorial

23 Jan 2021

Power price hike

ALREADY struggling to cope with the impact of the Covid-19 pandemic and rising food prices, consumers received yet...
Updated 23 Jan 2021

Israeli land grab

WITH the chapter now closed on the Trump presidency, the eyes of many in the international community — ...
23 Jan 2021

New PhD policy

EARLIER in the week, the HEC chairman announced several changes for undergraduate and PhD degrees in the country....
Updated 22 Jan 2021

Time to heal

A multitude of foreign issues will test Biden’s mettle and require progressive thinking.
22 Jan 2021

Foreign funding

AS the pressure builds on his party in the foreign funding case, Prime Minister Imran Khan has called for an ...
22 Jan 2021

Decaying PTV

THE Cabinet Committee on State-Owned Enterprises has decided to remove Pakistan Television from the list of...