an extinct cephalopod mollusc with a bullet-shaped internal shell that is typically found as a fossil in marine deposits of the Jurassic and Cretaceous periods 箭石(有子弹内壳的头足类软体动物,已绝种,其化石多见于侏罗纪和白垩纪时期的海洋沉积中)
Order Belemnoidea, class Cephalopoda: many genera 箭石目,头足纲: 多属
语源
early 17th cent.: from modern Latin belemnites, based on Greek belemnon 'dart'