A tetrapod is a vertebrate animal that has four limbs. This group includes amphibians, reptiles, birds, and mammals. Tetrapods evolved from fish around 360 million years ago, adapting to life on land. Their limbs are structured to support movement on solid ground, allowing them to explore various environments. Tetrapods have a backbone and are part of the phylum Chordata. They typically have lungs for breathing air, although some, like certain amphibians, can also absorb oxygen through their skin. The evolution of tetrapods marked a significant transition in the history of life, leading to the diverse range of terrestrial animals we see today.