Note that “the oldest species of <x>” doesn’t make any sense. Both that species as well as its closest evolutionary relative have a last common ancestor, meanin

Note that “the oldest species of <x>” doesn’t make any sense. Both that species as well as its closest evolutionary relative have a last common ancestor, meaning they are equally “old”. Do this a few times and you will notice all species have the same “age”, assuming life today all descendent from a common ancestor. Yes, some of them have may have changed more or less in appearance, but that correlates poorly with genetic changes.