Dating back to the time of the giant Megalodon shark, these are four large fossilized clams found in stone, from the Miocene Period. They were found in the desert of western coastal South America, in hard rock. Each one was laboriously worked with pneumatic and hand tools to expose the fossils entombed in the original host rock that was once a 20 million year ocean floor. Color is natural and contrasts well with the light sand-colored stone. From a German private collection formed in the 1980's. Impossible to find or collect today due to highly restrictive South American fossil export prohibitions!
Bivalves, which include clams and mussels, are made up of two half shells. The valves are attached by a hinge ligament and articulate open and close by two muscles attached on the inside of the shells. Bivalves are filter-feeders and pump water inside their bodies to strain out phytoplankton and other small organisms for food. Bivalves generally have limited locomotion and possess a foot but mainly live attached to some type of substrate or burrow in the underwater sand. Bivalves move along the bottom by means of jumping. The foot is extended then contracted violently, moving backwards in the process acting like a spring always kicking the animal slightly forward.