Animals commonly called reptiles, amphibians, birds, and mammals are all tetrapods – a term that means "four feet." The transition from water to land is fascinating to scientists in part because it’s our history – the transition documents the evolution of tetrapods, and humans are tetrapods. Tetrapod for a clade. Which of the following is true of tetrapods?
a. Tetrapods are more complex than non-tetrapods.
b. Tetrapods are more evolved than non-tetrapods.
c. Tetrapods are more closely related to each other than to non-tetrapods.
d. All of the above