Belemnoids are an extinct group of marine cephalopod, very similar in many ways to the modern squid and closely related to the modern cuttlefish. Like them, the belemnoids possessed an ink sac, but, unlike the squid, they possessed ten arms of roughly equal length, and no tentacles. The name "belemnoid" comes from the Greek word βέλεμνον, belemnon meaning "a dart or arrow" and the Greek word είδος, eidos meaning "form".
Megateuthis gigantea is the largest known belemnite species, reaching about 50 mm and 700mm in maximum diameter and length of rostrum, respectively. The fossil remains were discovered in Europe and Asia.
Belemnotheutis is an extinct coleoid cephalopod genus from the middle and upper Jurassic, related to but morphologically distinct from belemnites. Belemnotheutis fossils are some of the best preserved among coleoids. Remains of soft tissue are well-documented in some specimens, even down to microscopic muscle tissue. In 2008, a group of paleontologists even recovered viable ink from ink sacs found in several specimens.
Aulacoceras is a genus of belemnite, an extinct group of cephalopods.
Belemnopsis is a genus of belemnite, an extinct group of cephalopods.
Brevibelus is a genus of belemnite, an extinct group of cephalopods.
Conoteuthis is a genus of belemnite, an extinct group of cephalopods.
Dicoelites is a genus of belemnite, an extinct group of cephalopods.
Diplobelus is a genus of belemnite, an extinct group of cephalopods.
Gonioteuthis is a genus of belemnite, an extinct group of cephalopods. It grew to a body length of 8 inches and fed on small marine animals. Fossils of Gonioteuthis have been found in the Netherlands, Germany, and Sweden in rocks dated to the late Cretaceous Period, specifically 85 to 70 million years ago.
Hibolites is a genus of belemnite, an extinct group of cephalopods.
Mesoteuthis is a genus of belemnite, an extinct group of cephalopods.
Neohibolites is a genus of belemnite, an extinct group of cephalopods.
Parapassaloteuthis is a genus of belemnite, an extinct group of cephalopods.
Permoteuthis is a genus of belemnite, an extinct group of cephalopods.
Rhabdobelus is a genus of belemnite, an extinct group of cephalopods.
Salpingoteuthis is a genus of belemnite, an extinct group of cephalopods.
Rhabdiferoceras is an extinct genus of orthocerids belonging to the Baltoceratidae that lived in what would be North America during the Cassinian Stage at the end of the Early Ordovician, existing for approximately two million years from about 474 -472 mya.
Belemnitida is an extinct order of squid-like cephalopods that existed from the Late Triassic to Late Cretaceous. Unlike squid, belemnites had an 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 pointy 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 is a genus of an extinct group of cephalopods belonging to the order Belemnitida. These cephalopods existed in the Early Jurassic period from the Hettangian age to the Toarcian age (175.6–183.0). They were fast-moving nektonic carnivores.
