The Nautilus, Greek for 'sailor', is a mollusk that has survived unchanged for millions of years. They represent the only living member of the subclass Nautiloidea, and are often referred to as 'living fossils'.
Calcite with quartz from Huanggang Mine, Inner Mongolia, China. The pictured specimen is 7cm tall. The quartz at the center of the stacked calcite disks is better exposed in some of the specimens that they have at the show. Photo credit: Jeffrey A. S