Final answer:
The coccyx, or tailbone, is formed by the fusion of four small coccygeal vertebrae, usually between the ages of 25 and 30. It attaches to the sacrum, supports some weight when sitting, and connects to ligaments and muscles of the pelvic floor.
Step-by-step explanation:
The coccyx, commonly referred to as the tailbone, is situated at the lower end of the vertebral column. It is formed by the fusion of four small coccygeal vertebrae. This fusion usually occurs between the ages of 25 and 30. The coccyx connects with the sacrum and, though it does not bear weight while standing, it may support some body weight when a person is sitting. The coccyx also serves as an attachment point for ligaments and muscles of the pelvic floor.
Given its position and structure, the coccyx completes the vertebral column which provides protection to the spinal cord and supports the head and torso. It is an important part of the skeletal system despite its small size and the fact that it is not directly involved in weight-bearing in a standing position.