True teeth are only found in backboned vertebrates, like fish and mammals. Some invertebrates have tooth-like structures, but the underlying tissues are completely different.

Having an internal structure that protected the tooth meant these animals had a stronger and better bite. The team also examined "unerupted" teeth, which had not yet broken through the gums.

Though notoriously short-armed, the T. Rex had other genetic advantages: namely, its teeth. Researchers have found that the saw-like internal tooth structure of carnivorous dinosaurs like the ...

Unlike previous studies of extinct and current sawfish, this one probed the internal structure of the scales’ hard outer layer, called enameloid. “It’s basically the primitive form of [tooth ...

Teeth first evolved as sensory organs, not for chewing, according to a new analysis of animal fossils.The first tooth-like structures seem to have been sensitive nodules on the skin of early fish ...