Researchers have confirmed that lizards exhibit two sleep states, just like humans, other mammals, and birds. They corroborated the conclusions of a 2016 study on the bearded dragon and conducted the same sleep investigation on another lizard, the Argentine tegu. Their findings nevertheless point out differences between species, which raises new questions about the origin of sleep states.

Robots may one day tackle obstacles and traverse uneven terrains thanks to collaborative research analyzing the motion of lizards. The study used a slow motion camera to capture the nuanced movement of eight species of Australian agamid lizards that run on two legs -- an action known as 'bipedal' movement.