Cambrian
adjective geology specialized uk/ˈkæm.bri.ən/ us/ˈkæm.bri.ən/
寒武纪的（寒武纪，距今约5.43亿至4.9亿年前的地质时期，无脊椎动物开始大量出现。）
from or referring to the period of time between about 543 and 490 million years ago, in which many different types of invertebrates (= animals with no back bone) first appeared
the Cambrian period 寒武纪时期
Cambrian rocks 寒武纪时期的岩石
the Cambrian
noun [ S ] ukus
寒武纪
the Cambrian period