The enamel of Creodonta, Arctocyonidae, and Mesonychidae (Mammalia), with special reference to the appearance of Hunter-Schreger-Bands

The enamel structure of 16 creodont genera was examined by light microscopy and for 3 by scanning electron microscopy. All creodonts have prismatic enamel where prisms decussate in layers forming Hunter-Schreger-Bands (HSB). As only limited material was accessible to sectioning, the main emphasis is given to the appearance of HSB. As in other carnivorous mammals three types of HSB can be distinguished: undulating HSB, acute-angled HSB and zigzag HSB, which differ in their waviness in the horizontal course. Within the evolution of creodonts the amount of zigzag HSB in the teeth increased in hyaenodontids and oxyaenids respectively. This can be attributed to different loading conditions of the teeth due to various food types and the resulting bite forces. Tendencies to ossiphagous feeding habits correlate with zigzag HSB. The same general trends can be seen in 5 examined genera of the Arctocyonidae and Mesonychidae.