Vestigial-Structures

Vestigial organs are those structures in some organisms which have no apparent function in their bodies but once they were functioning. They are considered a residual part of a past ancestor. In case of snakes, for example, they possess pelvic bones but they do not have legs so these non-functional pelvic bones are vestigial structures. Like many other organisms, there are a few Vestigial organs in humans.
As in many other organisms, humans also have vestigial organs. There are many examples of vestigial organs in humans. A few of them are the vermiform appendix, tailbone, erector pili muscles and wisdom teeth etc.
Source:
1-http://explainry.com/biology/vestigial-organs-humans/
2-https://www.youtube.com/channel/UCZYTClx2T1of7BRZ86-8fow
3-http://www.livescience.com/21513-vestigial-organs.html