Of,belonging to,or characteristic of the geologic time,rock series,and sedimentary deposits of the fourth epoch of the Tertiary Period,characterized by the development of grasses and grazing mammals.

• 中新世的与以草本植物和食草哺乳动物的发展为特征的第三纪第四世的地质时代、岩系和沉积层有关的，属于这一世的