The Registry of World Record Size Shells is a conchological work listing the largest (and in some cases smallest) verified shell specimens of various marine molluscan taxa. A successor to the earlier World Size Records of and R. Tucker Abbott, it has been published on a semi-regular basis since 1997, changing ownership and publisher a number of times. Originally planned for release every two years, new editions are now published annually. Since 2008 the entire registry has been available online in the form of a searchable database. The registry is continuously expanded and now contains more than 24,000 listings and 85,000 supporting images.