Silurian
adjective geology specialized uk/saɪˈlʊə.ri.ən/ us/sɪˈlʊr.i.ən/
志留纪的（迄今约4亿4500万至4亿2000万年前的地质时间段，此时期有颌骨的鱼类以及陆地上的植物和小型动物第一次出现）
from or referring to the period of time between about 445 and 420 million years ago, in which fish with jaws (= mouth bones) and some plants and small animals on land first appeared
the Silurian period 志留纪
Silurian rocks 志留纪岩石
the Silurian
noun [ S ]
志留纪
the Silurian period