a conical calcareous fossil tapering to a point at one end and with a conical cavity at the other end containing (when unbroken) a small chambered phragmocone from the shell of any of numerous extinct cephalopods of the family Belemnitidae
例句
用作名词(n.)
Any of various mineral concretions, such as a belemnite, formerly supposed to be thunderbolts.很多矿物结核如箭石过去被认为是雷石。
