时间:2022-09-19 20:11:57
n.
【古生物学】箭石〔乌贼类化石〕。
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