Which of the following is NOT a vestigial organ in human body?

Vestigial organ is an organ that once was useful in an animal’s evolutionary past, but that

now is useless or very close to useless. Some of

the vestigial organs in human body are: appendix, tailbone, wisdom teeth, mail nipples, body

hair, pharynx and thymus gland. The thyroid

gland is part of the endocrine system and is responsible for producing and releasing thyroid

hormones into the bloodstream.