Answer
The coccyx is also known as the tailbone. It comprises 4 -5 coccygeal vertebrae (Co 1-Co 4/5) which fuse to form one bone by adulthood (20-30 years), but usually by age 25 years. The first vertebrae in the coccyx (Co 1) is distinguished by a pair of projections (horns) which provide points of attachment for ligaments that bind sacrum and coccyx together.
Work Step by Step
. The vestigial coccyx also has another important function -it supplies points of attachment for muscles of the pelvic floor.
