Parietal Bone
Flat Bone, part of the core skull
Also known as: Roof Bone
Classification
Flat Bone, part of the core skull
Dimensions
Roughly quadrilateral and curved, measuring about 15 centimeters across in an adult, forming a smooth, protective dome shape.
Key Features
Curved, smooth outer surface, square or rectangular outline, and zigzag jagged edges along the borders where it knits together with neighboring skull plates.
Similar Bones
Frontal bone or occipital bone. The frontal bone is typically more wedge-shaped with brow ridges, while the occipital bone sits lower down at the back and features a large opening at its base.
Across Species
In mammals, these pair up to form the roof of the head, whereas in many reptiles and fish, the skull features a much more complex mosaic of smaller plates. Birds fuse many of these head bones together into a lightweight single structure for flight.
Evolutionary History
Originating from dermal armor plates in ancient primitive fish, these flat bones moved inward over hundreds of millions of years to encase and protect the growing brain of land-dwelling vertebrates.
Photography Tips
Take pictures from directly above against a contrasting background to show the curved shape and the intricate zigzag borders clearly, using soft, side-angled lighting to highlight the natural surface texture.