Enamel texture of the tritylodontid mammal-like reptile, occurred from the lower Cretaceous in central Japan

Fossil teeth of the early Cretaceous mammal-like reptile (Tritylodontidae) were observed in the internal texture in relation to tooth development and evolution. The materials were discovered from the Tetori Group which is distributed in the western area of the central mountains of Japan, and these materials are the first mammal-like reptile discovered from the Cretaceous strata in the world. The authors investigated these fossil teeth of Tritylodontidae which is considered as most evolved mammal-like reptile in their microstructure, and found the characteristic texture of the enamel which is similar to the enamel prism which is common in the enamel of the modern mammals.