People who think sharks are “primitive” fish may be commended as being reasonably up-to-date with the evolutionary literature, but they need to take note of a new fossil fish that has thrown all the ideas into the melting-pot. Only a year ago, as an apparently coherent story was beginning to emerge, a specialist in vertebrate biology explained that the common ancestor of all jawed vertebrates on Earth resembled a shark.
“The common ancestors of all jawed vertebrates today organized their heads in a way that resembled sharks. Given what we now know about the interrelatedness of early fishes, these results tell us that while sharks retained these features, bony fishes moved away from such conditions.” (Source here)
For more, go here.