The common ancestor X is often called the “missing link” between the descendant groups. It is the genealogical connection between birds and modern reptiles—the intersection you’d finally reach if you traced their lineages all the way back.
This is misleading. "X" in the fake diagram isn't the missing link, the missing link is A through Z. You don't have a single connected link in the whole chain. You have a bunch of perfectly formed, independently created links that are only interconnected in the fact that they are designed by the same creator (who is perfect so he used the same perfect parts and design)
