There is evidence that frogs have roamed the Earth for more than 200 million years, at least as long as the dinosaurs.
The world's largest frog is the goliath frog of West Africa—it can grow to 15 inches and weigh up to 7 pounds. A goliath frog skeleton is featured in Frogs: A Chorus of Colors.
One of the smallest is the Cuban tree toad, which grows to half an inch long.
While the life spans of frogs in the wild are unknown, frogs in captivity have been known to live more than 20 years.
There are over 6,000 species of frogs worldwide. Scientists continue to search for new ones.
Toads are frogs. The word "toad" is usually used for frogs that have warty and dry skin, as well as shorter hind legs.