Question

What is most likely similar to a common ancestor of all vertebrates?

Answer 1

a stunningly preserve soft body fish more than 500 million years old could be the similar to a common ancestor of all vertebrates ...

Answer 2

Explanation:

But the underlying similarities of these homologous bones reveal that all these animals share a common ancestor: a four-legged animal--a tetrapod--living over 365 million years ago. This cladogram shows the common ancestor of modern vertebrates, why they are similar, and indicates points of divergence through time.