Lungfish teeth never change, according to Nature vol 411, p548, 31 May, 2001. Lungfish have a unique pattern of teeth on the palate (roof of the mouth) and inner surface of the lower jaw. New teeth are continually formed but old ones are not shed. This results in adults having many rows of teeth on the roof of the mouth and lower jaw – an arrangement of teeth unique to lungfish. Robert Reiz of the University of Toronto, and Moya Smith of the Dental Institute, Kings College London studied the teeth of fossil and living lungfish and were surprised to find they are exactly the same even though Reiz and Smith believe they “are separated by 360 million years of evolution.”
Editorial Comment: Teeth are not the only distinctive features identical in fossil and living specimens of lungfish. Every study of fossil and living lungfish has revealed they are the same. For this reason lungfish are often described as living fossils, i.e. no evolution has occurred between the time the fossil formed and the present day living lungfish, no matter how many years you think they are separated by. (Ref. Lungfish, kind, living fossil)