The feeding habits of mammals can be distinguished from the morphological types of teeth, such as deer, sheep, cattle and other herbivores, whose crowns are crescent-shaped teeth, just like ridge-shaped teeth; Tigers, dogs and other carnivores have a pair of obvious canine teeth, and the molars are in the shape of a three-cone (pen rack); The canine teeth of omnivores such as pigs, giant pandas and apes are degenerated, and the molars are mound-shaped. The change degree of molar crown morphology can relatively judge the order of biological evolution. For example, the more complex the crown type, the higher the degree of evolution of such creatures.
Mammalian tooth fossils are mainly produced in Neogene and the lower part of Quaternary, and the original species are from Paleogene, with more in North China and less in South China. Generally speaking, tooth fossils with high degree of fossilization, bright and dense enamel on the tooth surface and broken teeth can be used as ornamental stones. If they are attached to solid surrounding rock or rows of teeth are attached to the lower jaw, the value is higher (Figure 9.60).