The microscopic structure of Ectoganus
tooth enamel consists of a single main layer. The internal enamel feature known as the
Hunter-Schreger band is present but is weakly developed. The enamel is composed of tightly packed rod-like structures (
prisms) that show a keyhole-shaped cross-section and only a partially formed outer sheath. The underlying
dentine — the main structural tissue of the tooth — follows a typical mammalian pattern. A relatively thick layer of
cementum, the tissue that helps anchor teeth in the jaw, covers both the front and back surfaces of the teeth. == Phylogeny ==