If you were assigned the task of constructing a cladogram representing the evolutionary relationship between amphibians, turtles, lizards, snakes, crocodiles, birds, and mammals, what feature could you use as the shared derived trait?

A) presence of a beak
B) presence of hair
C) give birth to live young
D) four limbs
E) production of milk to nourish their young

Four limbs are a shared derived trait among amphibians, turtles, lizards, snakes, crocodiles, birds, and mammals. All of these animals have four limbs, or are descended from ancestors that had four limbs. This trait is not found in any other group of animals, so it is a useful characteristic for constructing a cladogram that shows their evolutionary relationships.