What bone are you not born with?

What bone are you not born with? One example of a bone that babies are born without: the kneecap (or patella). The kneecap starts out as cartilage and starts significantly hardening into bone between the ages of 2 and 6 years old.

One example of a bone that babies are born without: the kneecap (or patella). The kneecap starts out as cartilage and starts significantly hardening into bone between the ages of 2 and 6 years old.