A vestigial structure in humans is

Explanation

A vestigial structure in humans is the tailbone, also known as the coccyx. Vestigial structures are anatomical features that have lost their original function over the course of evolution. These structures were once functional and served a purpose in the ancestors of the species but have become reduced or non-functional in the present-day descendants. The tailbone, or coccyx, is a small triangular bone located at the base of the vertebral column in humans. It is a vestige of the tail that was present in the early ancestors of mammals, which had tails for various functions, such as balance, communication, or grasping.