19. The Coccyx formation is an odd one
The Coccyx, known today mostly as the tailbone, happens to be the end of your vertebrae. It’s actually the home of where our tails used to be too. Just about every mammal on Earth had a tail at some point in their evolutionary history. Even today, some humans actually grow a version of a tail. This ultimately proves that all humanoids had them at some point.
In fact, during the 14 to 22-week stages of human embryogenesis, you can actually view a child inside the mother’s womb and notice a tail-like formation. It’s eventually absorbed by most of us, except for those that were referred to earlier. To most, this is one of the coolest ways evolution is proven. This viewable formation of a child shows, somewhat, a process of humans from their ancestral state into their current form, all in nine months.