柯林斯詞典index fossil 1. N a fossil species that characterizes and is used to delimit a geological zone 標(biāo)準(zhǔn)化石 (Also called zone fossil) 返回 index fossil劍橋詞典a fossil that is found in many places and comes from the same time in history , so that scientists can use it to decide how old certain rocks are 標(biāo)準(zhǔn)化石 返回 index fossil