Denticles are small, tooth-like structures that can be found on certain animals, such as sharks and rays. These structures are important for helping these animals to move through the water more efficiently, and they also serve as a form of protection against predators. Some synonyms for denticles include dermal denticles, placoid scales, and shark scales. These terms refer to the same type of structure, but are often used in different contexts or by different groups of scientists. Regardless of the term used, denticles are an important adaptation for many aquatic animals, and their unique structure provides insight into the evolution of these species.