Definitions for "Belemnite"
A conical calcareous fossil, tapering to a point at the lower extremity, with a conical cavity at the other end, where it is ordinarily broken; but when perfect it contains a small chambered cone, called the phragmocone, prolonged, on one side, into a delicate concave blade; the thunderstone. It is the internal shell of a cephalopod related to the sepia, and belonging to an extinct family. The belemnites are found in rocks of the Jurassic and Cretaceous ages.
A conical fossil tapering to a point at one end 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. Found in seas and oceans of the Mesozoic era, between 66-245 million years ago. View our collection of Opal Belemnites.
an extinct (in early Tertiary) marine organism with a cone-shaped shell.