Denticle (tooth feature)

Denticle refers to a small, tooth-like projection found on various structures within the animal kingdom, most notably among sharks and other fish, as well as on the skin of reptiles and in the oral cavity of some mammals. Denticles play a variety of roles, from protection to locomotion, and their structure and function can vary significantly across different species.

Structure and Function

Denticles are typically composed of dentin, a calcified tissue that is also found in human teeth, covered by a layer of enamel or enameloid. This composition provides them with a high degree of durability and resistance to wear and tear. In sharks, for example, denticles are not only found in the mouth but also cover the skin, where they are known as dermal denticles. These skin denticles reduce friction between the shark and the water, allowing for more efficient movement. They also provide protection against predators and parasites.

In reptiles, skin denticles can serve a similar protective function, and in some species, they are involved in camouflage or display. In the oral cavity of mammals, such as in the gums of certain rodents and primates, denticles can help in the mechanical processing of food.

Evolutionary Significance

The presence of denticles across a wide range of species points to their evolutionary significance. They are considered to be an ancient feature, with fossil records indicating their presence in early vertebrates. The variation in denticle structure and function across different taxa provides insights into the adaptive strategies of animals in response to their environments.

Research and Applications

Research into denticles has applications in both biology and materials science. The study of shark skin denticles, for example, has inspired the development of biomimetic materials designed to reduce friction in water, with potential applications in improving the efficiency of ships and underwater vehicles. Additionally, understanding the growth and development of denticles can contribute to the fields of developmental biology and paleontology, offering clues about the evolutionary history of vertebrates.

See Also

• Tooth
• Shark
• Dentin
• Enamel
• Biomimetics