This bivalve is widespread in coastal waters and on the ocean shelves of the North Atlantic. In North America it is usually called the Ocean Quahog (pronounced ko-hog).
Arctica islandica dates back to at least the early Cretaceous about 135 million years ago. Individual Icelandic Cyprines live for hundreds of years, the oldest living non-colonial animal known. One specimen was 507 years old when it died. Their shells have growth lines rather like trees, which record the years and the environmental conditions. They are being studied to help reconstruct as sequence of climate changes in the past.
Our greenhouse gas emissions not only cause global heating and sea level rise, the increased carbon dioxide absorbed by the oceans' waters leads to acidification, a lowering of the sea water's pH. This will have devastating effects on ocean biodiversity, making a major contribution to the Sixth Mass Extinction, the beginnings of which we are now witnessing. The Icelandic Cyprine, however, can survive high levels of CO2 in the water, having survived the end-Cretaceous mass extinction and the Paleocene-Eocene Thermal Maximum (PETM) 55 million years ago. Even if we manage to drive our own species to extinction, this little clam is likely to survive us.
Look out for Arctica Islandica on the beach. You might walk over a thousand cockles, mussels, oysters, razor clams, piddocks, tellins and gapers before spotting an Icelandic Cyprine, but when you do, it may be the shell of the oldest creature you've ever seen. And it's descendants may have a longer future than humanity.