The world's smallest chameleon has been discovered with "surprisingly" large genitals.

Chameleon

Chameleon

The Brookesia nana was found in Madagascar is just 21.6mm long but its private parts make up nearly 20 per cent of the creature's body weight when flexed.

Details about the chameleon were revealed in a study published in the journal Scientific Reports recently. The lizard had escaped the attention of researchers in the past due to its size and ability to camouflage.

The study's co-author Dr. Mark D Scherz told IFLScience: "It takes a lot of patience and an eye for it.

"With practice, one can get relatively good at it, but we often work with local guides who are particular experts in finding these tiny chameleons as well."

Scherz explained that the male chameleons have large genitals as they are much smaller than females.

He said: "We know that Brookesia species have substantial sexual size dimorphism, with the males much smaller than females.

"So it makes sense that their genitals are limited in ways their bodies aren't."