Belemnitida

Common card · No. 206717

Belemnitida (or belemnites) is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous (and possibly the Eocene). Unlike squid, belemnites had a mineralized internal skeleton that made up the cone. The parts are, from the arms-most to the tip, the tongue-shaped pro-ostracum, the conical phragmocone, and the pointed guard. The calcitic guard is the most common belemnite remain. Belemnites, in life, are thought to have had 10 hooked arms and a pair of fins on the guard. The chitinous hooks were usually no bigger than 5 mm (0.20 in), though a belemnite could have had between 100 and 800 hooks in total, using them to stab and hold onto prey. Belemnites were an important food source for many Mesozoic marine creatures, both the adults and the planktonic juveniles and they likely played an important role in restructuring marine ecosystems after they rose to ecological prominence in the aftermath of the Triassic–Jurassic extinction event. While highly abundant...

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