Ancestor to mammals was the original venomous vertebrate

Snakes are today’s kings of venom‚ but they weren’t the first‚ that title goes to a dog-sized ancestor to mammals with a toxic bite.

Researchers believe they have found evidence for the oldest vertebrate to have used venom.

The creature is Euchambersia‚ mirabilis that lived about 255 million years ago‚ in what is now the Karoo.

It is likely to have been using venom more than a 100 million years before the arrival of the first snake.

Researchers at the Bernard Price Institute for Palaeontological Research at the University of the Witwatersrand and the Natural History Museum of London believe they have found evidence of Euchambersia’s secret through the use of cutting edge technology.

They used CT scanning and 3D imagery techniques to analyse the only two known Euchambersia skulls found.

What it revealed was a circular structure‚ known as a fossa that sat behind the canine teeth in its upper jaw.

According to measurements of the two fossils, the Euchambersia was a small dog-like pre-mammalian reptile that grew between 40 and 50cm long, and lived well before the first dinosaur even appeared. Photo supplied by Wits.

The academics suspect this was where the venom was produced and delivered into the mouth via a network of bony grooves.

Snakes have a more sophisticated delivery system by injecting venom into their prey through their fangs.

“This was passive transmission‚ where the venom would have mixed with the saliva‚” explained Dr Julien Benoit‚ of Wits university‚ who believed Euchambersia’s primary use of this deadly cocktail would have been for hunting.

A secondary use‚ for this animal that only weighed in at 5kg‚ would probably have been defence.

Euchambersia is considered a pre mammalian reptile because of a number of anatomical adaptions it shares with mammals today‚ including specialised teeth and a Zygomatic arch.

Benoit said that Euchambersia appeared to be a short lived evolutionary experiment and quickly became extinct.

But the venom gene lived on and is active in some mammals today.

Some species of shrew and the Loris‚ a primate from South East Asia have venom.

Professor Bruce Rubridge of the Bernard Price Institute for Palaeontological Research‚ who also worked on the study‚ said that for a long time it was suspected that Euchambersia had venom. But finally technology allowed them to take a special peek into Euchambersia’s skull.

“One problem with fossils is that you have to be careful not to destroy evidence that you might need in 50 years time. With this technology you can look right into the skull without damaging the fossil‚” said Rubridge.

What Benoit can't work out is how potent Euchambersia’s bite was.

“We do know that it did produce a lot of venom‚” said Benoit.

- TMG Digital/The Times