Overview

Denticles are the small, tooth‑margin bumps or serrations that form a jagged cutting edge on many kinds of teeth. They occur along the carinae (cutting edges) of teeth in a range of animals and vary widely in size, spacing and shape. Denticles improve a tooth's ability to slice, grip or shred material and are an important character in comparative anatomy and fossil identification. For a simple illustration of location, see a diagram of a tooth.

Characteristics and variation

Key features used to describe denticles include their density (often reported as denticles per millimetre), profile (rounded, pointed, or blade‑like), and whether they occur on the leading (anterior) or trailing (posterior) edge of the tooth. Some teeth show a continuous series of fine denticles; others have coarse, widely spaced serrations. Microscopical study, including scanning electron microscopy, reveals wear patterns and fine structure that reflect diet and feeding mechanics.

History and study in paleontology

Paleontologists rely on denticle morphology to classify isolated and fragmentary teeth recovered from the fossil record. Features of serrations are diagnostic in many groups and help distinguish taxa when other bones are absent. The study of denticles is a routine part of systematic descriptions in paleontology and is applied to fossils from multiple eras, notably among predatory dinosaurs and other carnivores.

Functions and examples

  • Cutting and slicing: Serrated teeth concentrate force on narrow points, aiding penetration and cutting—useful for flesh‑eating animals.
  • Grip and tear: Denticles can help retain slippery prey and propagate a tear as the tooth is retracted.
  • Taxonomic examples: Theropod dinosaurs and some modern reptiles such as varanid lizards (for example, the Komodo dragon) bear serrated teeth. Many cartilaginous fishes also show serrated forms; see examples among sharks.
  • Occasional occurrence in mammals: Certain extinct and a few living mammals show serrated or crenulated enamel margins used for specialized diets; specialists note these occurrences among some mammals.

Terminology and notable distinctions

Denticles should be distinguished from cusps (raised points on a tooth crown) and from dermal denticles (tooth‑like scales in sharks’ skin). The term "ziphodont" describes laterally compressed, blade‑like teeth with serrations commonly seen in some extinct predators. When describing denticles, researchers note symmetry, curvature and wear because these aspects carry functional and evolutionary information.

Importance

Beyond feeding mechanics, denticle analysis informs ecology, behavior and evolutionary relationships. Because the details of serrations preserve well in many fossils, they are a reliable source of data for reconstructing diets and distinguishing closely related species when other skeletal material is missing.