Lizards more venomous, more closely related to snakes, than thought

This video is called Bearded Dragon Hatchling 1.

From World Science:

Snakes and lizards share venom, evolutionary history, study finds

Nov. 16, 2005

Courtesy Nature and World Science staff

Conventional wisdom has it that, among reptiles, venom delivery is mainly associated with snakes, and that it underlies their dramatic evolutionary success: 2,500 out of 3,000 snake species are poisonous.

In contrast, venom delivery is found in just two lizard species, in which it is thought to have evolved independently from snakes.

But a new study by Bryan Fry of the University of Melbourne, Australia, and colleagues has found that that venom delivery among lizards may be much more widespread.

The researchers said they showed that members of two additional lizard lineages also produce and can deliver venom toxins. The lineages include Monitor Lizards and Eastern Bearded Dragons, a popular pet.

The new work suggests the side-effects of nasty lizard bites may actually be due to venom rather than incidental bacterial infection, as was previously thought, Fry and colleagues asserted.

Also, they said, the findings suggest snakes and lizards are much more closely related than has been previously believed.

Snakes evolved from relatively advanced lizards, they suggested, rather than being a separate branch on the evolutionary tree.

The study is to be published online by the research journal Nature this week.

Among living reptile species, only the Gila Monster and Beaded Lizard were previously known to be poisonous, the researchers wrote.

They claimed to have found toxins in four Monitor species and the Eastern Bearded Dragon.

See also here on snakes and lizards’ evolution.

This video is called Hatching Bearded Dragon.

How bearded dragons switch their sex. Extreme temperatures might mess with RNA from two genes: here.

Escaped aesculapian snakes in Welsh zoo: here.