Pliocene         
adjective  geology specialized uk/ˈplaɪ.ə.siːn/ us/ˈplaɪ.oʊ.siːn/
 上新世的(迄今约530万至180万年前的地质时间段,其间许多现代哺乳动物和现代人祖先开始出现)
from or referring to the period of time between around 5.3 million and 1.8 million years ago, in which many modern mammals and the first modern humans appeared
  the Pliocene epoch 上新世时代 
 the Pliocene
noun [ S ] ukus
 上新世
the Pliocene epoch (= part of a period of time in the earth's history)