Written by the Fiveable Content Team โข Last updated August 2025
Verified for the 2026 exam
Verified for the 2026 examโขWritten by the Fiveable Content Team โข Last updated August 2025
Definition
The tailbone, or coccyx, is a small, triangular bone at the base of the spinal column in humans and certain other primates. It's a vestigial structure, meaning it's a remnant of an organ or structure that had a function in our evolutionary past.
These are structures that have no apparent function and appear to be residual parts from a past ancestor.
Spinal Column: This is the series of vertebrae extending from the skull to the small of the back, enclosing the spinal cord and providing support for the thorax and abdomen; also known as backbone.