These shells are called Ocean Quahog (Arctica islandica) and I had to take a photo of them because I liked the way the pair was placed on the sandy beach.
In Norwegian we call them Cow-Shells, probably because of their beautiful red/brown color.
According to the Norwegian Wikipedia (the English version doesn’t have an article about ocean quahog shells) there have been found individuals of these shells that are as old as 220 years!
Check out my macro photo of a limpet shell.
Information about the picture:
Camera: Olympus E-500 digital SLR camera
Exposure: 0.013 sec (1/80)
Focal Length: 35 mm
ISO Speed: 100
Lens: Olympus Zuiko Digital 35mm F3.5 Macro
Location: Laupstad (Andørja), Troms in northern Norway