A walk on the wild side..
Costa Rica is home to three species of basilisks, lizards that run on water. Because they can run on water, members of the genus Basiliscus are often called Jesus Christ Lizards.
Scientists carefully examined video-taped sequences of the Common Basilisk (Basiliscus basiliscus) running across water, and built mechanical models in order to figure out how these large lizards cross water without sinking.
The scientists found that basilisks only run on their hindlegs, when darting across water. When they run, a narrow seam of skin around each of their toes forms moveable flaps that expand when their foot is pressed down on the water. This creates a larger surface area for them to run on.
When the lizard puts its foot down the water, an air-filled pocket is formed around the foot that quickly fills with water again. Before the water fills the air space, the lizard needs to pick up its foot so that it doesn't have to plow through the water.
When it picks up its foot, the moveable skin-flaps on the toes fold down against the sides of the toes to reduce friction against the air. This means that the lizard can move its foot through the air very quickly.
The combination of speed and specially adapted toe fringes allows these lizards to perform their impressive trick of running on water.
There are not many candidates that might potentially be able to walk on the water since most lack the ideal combination of a foot with a large surface area, combined with a relatively low body weight found in basilisks.
Apart from a few birds, no other animals have been able to copy this form of escape behavior.
More Interesting Facts
The force that the lizards put into the downward movement of their feet, produces an upward pressure, that by itself creates almost a quarter of the total force required to keep the lizard from sinking.
The combined pressure that is produced during a single downward and upward stroke of the foot can be enough to provide 111 % of the support required to make an adult basilisk run on water.
Small juveniles, with a body weight of less than 2 grams (0.07 oz.) are even capable of producing 225 % of the upward pressure necessary for an animal their weight, and may truly give the impression of skipping across the water surface.
Before an 80 kg human could match a running basilisks aquatic performance, he or she would have to run at a speed of almost 110 km/h across water, with a muscle force that is 15 times higher than an average person is capable of!