Arctica islandica, aka Icelandic Cyprine or Ocean Quahog, the size of a large fist and by far our bulkiest bivalve, was found on the strandline at Saunton Sands in March 2015. Normally living sub-tidally in soft sediment, but rarely seen on shore, this one must have been dislodged by the recent big swell.
It tops the list of long-lived animals at some 400 years, with one recorded example of 507 years old.
Photo by Rob Jutsum
Ocean Quahog