Frogs, birds, rabbits, and lizards all have different forelimbs, which makes sense when you consider their different lifestyles. interestingly, all of their forelimbs share the same set of bones the ulna, the radius, and the humerus. these same bones are also seen in fossils of the extinct animal eusthenopteron, which demonstrates common ancestry among these four groups of animals. hence, these forelimbs are an example of:

Homologous organs

Explanation:

Homologous organs are one of the morphological evidences in support of evolution, the belief that all living organisms are from the same ancestor. T

Homologous organ are organs found in different animals which are similar in structures but different in their basic functions.

Frogs, birds, rabbits and lizards are all considered to be in the animal's sub-group known as vertebrates. Their forelimbs, even though modified for different functions are built on the same fundamental plan known as five-digit or pentadactyl plan.

Hence, the forelimbs are example of homologous organs.

the endomembrane system i think