in taxon composed primarily of chitin Mollusca organ radula BTO:0001506 An anatomical structure found in mollusks and used for feeding. It is a minutely toothed, chitinous ribbon. It is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the molluscs, and is found in all classes of mollusks except for the bivalves. Wikipedia:Radula The first bona fide radula dates to the Early Cambrian,[3] although trace fossils from the earlier Ediacaran have been suggested to have been made by the radula of the organism Kimberella.[WP] UBERON:0004289