What is the coccyx?

Coccyx - is the lower end of the spinal column of man and consists of four nodules of bone, like tiny vertebrae, corresponding to the tail, which is found in lower animals. The bones are deeply buried in muscle tissue, but occasionally they jut backwards and are surrounded by a fold of skin, so as to form an actual tail. The name coccyx was given by the Greek physician Galen (c.A.D. 130-200) and comes from the Greek word for "cuckoo", as the bone rather resembles a cuckoo's bill.