Petrous Bone
The dense, pyramid-shaped part of the skull around the inner ear, the best source for preserving DNA in skeletal remains due to its high bone density and structural protection.
The petrous bone is the dense, pyramid-shaped section of the skull surrounding the inner ear, renowned for its high structural protection and ability to preserve DNA longer than most other tissues. Also known as the petrous inner portion, it is the preferred source of genetic material in skeletal remains due to its high endogenous density. Its anatomical uniqueness makes it critical for forensic and archaeological DNA extraction.
What this means in real life
When a person suffers a severe head injury, the petrous bone often remains intact while surrounding skull bones fracture—its extreme density makes it one of the last structures to break.
What it isn’t
It is not a separate bone but rather a specific anatomical region within the temporal bone. Many assume it is a standalone bone because of its distinct name and unique properties.
Commonly misused online
Social media sometimes refers to it as 'the hardest bone in the body' without qualification; technically, tooth enamel and some other structures are harder, though the petrous bone is the hardest true bone.
Based on 1 reference source, including primary sources. Last verified July 12, 2026.