Frogs Can Freeze Solid and Revive

Native to Cameroon and Equatorial Guinea, the goliath frog is the world's largest frog. It is roughly the size of a house cat.

Tetrapods such as Ichthyostega lived about 365 million years ago. They had limbs and spent time on land, and are ancestors of amphibians and every other land vertebrate.

Andrias davidianus can reach nearly two meters in length, though wild populations are critically endangered after decades of overharvesting.

Many amphibians absorb oxygen across thin, moist skin. Lungless salamanders, the largest salamander family, rely on it almost entirely.