phragmacone

A noun referring to the thin, conical, chambered internal shell of a belemnite, which may be either straight or curved.

• 🇨🇳指箭石类头足动物内部呈圆锥形、由分隔的房室组成的薄壳，可以是直的或弯曲的。

1. Internal shell of a belemnite C2 formal scientific

   The thin, conical, chambered internal shell (either straight or curved) of a belemnite, an extinct cephalopod.

   • The fossilized phragmacone was carefully extracted from the limestone.
   • Paleontologists studied the chambers of the phragmacone to understand the belemnite's buoyancy.
   • The curved phragmacone of this specimen suggests a distinct species.

   🇨🇳箭石的内壳