Evolving
from primitive fish over 350 million years ago, amphibians, with their primitive
legs and lungs, became the first vertebrates to conquer land. They remain,
however, linked to the aquatic environment they left, spending at least some
part of their life cycle in water. Of the three major groups of amphibians,
only two are found in North America: the Salamanders (Order: Caudata), and
the Frogs and Toads (Order: Salienta). Click to learn more.