‘The evolution of teeth in mammals’ charts the development of teeth through the fossil record. It begins with the Carboniferous period around 310 mya and follows the teeth development of animals that survived and evolved through the end-Permian (251 mya) and end-Cretaceous (66 mya) extinction events. Fossil teeth and skulls of synapsids provide evidence of the evolution of mammalian chewing. These include separation of the front and back teeth into different types, a new jaw joint, reorganization of the chewing muscles, two generations of teeth, a bony palate, and prismatic tooth enamel. The tribosphenic molar, first found in the early Cretaceous aegialodontids, was an essential first step toward evolving the teeth of today's mammals.