Question

Research the group sarcopterygii and explain why all terrestrial vertebrates from cows to humans are included in this group which describes fish?

Answer 1

Even though sarcopterygians are fishes, they are the common ancestor of all the tetrapodes (we humans included). Sarcopterygians have lobe-fins which are muscular fins with a single bone that articulates with the rest of the body. Lobe-fins are basically limb precursors. In fact, every vertebrate have lobe-limbs that originated from the lobe-fins of the sarcopterygians, so in a very real sense er and all the vertebrates alive are descendants of the sarcopterygians fishes that lived in the Devonian 419.2 million years ago.