The fin-limbs of sarcopterygiians show such a strong similarity to the expected ancestral form of tetrapod limbs that they have been universally considered the direct ancestors of tetrapods in the scientific literature .

The fin-limbs of sarcopterygiians are very similar to what people believe was the ancestral form of tetrapod limbs . This has caused them to be believed to be the direct ancestors of tetrapods in the scientific literature .
