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47-570: The Fernie Formation consists of marine sediments that were deposited in the Sundance Sea . Deposition took place throughout most of the Jurassic period, starting during the Hettangian stage in some parts of northeastern British Columbia and continuing until the mid-Tithonian , as determined from its fossil assemblages, including ammonites , molluscs and microfossils . The sediments were sourced from

94-414: A Gonioteuthis was likely the result of a failed predation attempt. Two other Gonioteuthis guard specimens exhibit a double-pointed tip, probably stemming from some traumatic event. One belemnite guard also presents a double-pointed tip, with one of the points projecting higher than the other, probably a sign of an infection or settlement of a parasite. A Neoclavibelus guard features a large growth on

141-595: A 25-foot (8 m) long pliosaur similar to Liopleurodon . Its fossils have been found in Alaska and Wyoming, which were both covered by the Sundance Sea when it was alive. During the periods of recession, dinosaurs and other Jurassic terrestrial animals frequented the shores, as evidenced by the Red Gulch Dinosaur Tracksite near Shell, Wyoming . Belemnite Belemnitida (or belemnites )

188-436: A belemnite. Belemnites had a radula – the "tongue" embedded in the buccal mass , the first part of a gastropod digestive system – similar to open ocean predatory cephalopods. The radula had rows of seven teeth, consistent with modern predatory squid. The statocysts – which give a sense of balance and function much like the cochlea of the ear – were large, much like in modern fast-moving squid. Like other cephalopods,

235-419: A few belemnites also had aragonite guards, and the alveolar side of the guards of belemnitellids may have also been of aragonite. The pro-ostracum probably supported the soft parts of the belemnite, similar to the gladius of squid, and completely surrounded the phragmocone. The phragmocone was divided by septa into chambers, much like the shells of cuttlefish and nautiluses . The chambered phragmocone

282-447: A group that includes squid and octopuses , and are often grouped into the superorder Belemnoidea , though the higher classification of cephalopods is volatile and there is no clear consensus on how belemnites are related to modern coleoids. Guards can give information on the climate, habitat, and carbon cycle of the ancient waters they inhabited. Guards have been found since antiquity and have become part of folklore. The belemnite cone

329-459: A group, seemed to feature a reduction of the projection of the otherwise conical phragmocone into the pro-ostracum. That of the most ancient order Aulacocerida is orthoconic (none projects), Phragmoteuthida three-quarters projects, Belemnitida a quarter, and the most developed Diplobelida an eighth. The first mention of belemnites in writing comes from the Greek philosopher Theophrastus , who lived in

376-419: 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

423-414: A protective material that may have allowed the embryo to survive at greater depths and colder temperatures, develop into adults faster, and allow juveniles and adults to venture into deeper waters. Further, the protoconch would have allowed them to form limbs before reaching the phragmocone stage, and thus inhabit the open ocean earlier. These may have allowed belemnites to colonize a range of habitats across

470-414: A protoconch, a developing guard, and a solid guard. The developing guard tightly surrounded the protoconch. The embryonic shell consisted of an ovoid protoconch and several chambers. The protoconch had two layers, and several compartments - called "protoconch pockets" - formed between the layers, which may have stored gas or liquid in life to stay buoyant. The protoconch and guard were probably made of chitin,

517-400: A protoconch. The phragmocone, thus, developed after hatching. Ammonites are thought to have done the same, implying a similar reproductive strategy, and, considering both reached cosmopolitan distributions , a rather efficient one. Belemnite hatchling protoconches are estimated to have been generally around 1.5 to 3 mm (0.059 to 0.118 in). The guards of Megateuthis elliptica are

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564-410: A single female may have laid between 100 and 1,000 eggs. Hatchlings were either miniature forms of adults or went through a larval stage. According to the latter model, the egg was formed by the protoconch and a single-layered shell wall. During the larval stage, the protoconch became internal and the guard began to form. The embryo of Passaloteuthis , the most well-studied among belemnite embryos, had

611-427: A strongly hooked uncinus was designed to stab prey at a constant angle. It would force and sink in deeper if the prey tried to move away from the belemnite. Hook shapes and forms vary from species to species. In Chondroteuthis , large hooks were common near the mouth, and were either used for surrounding small prey or ramming into large prey; however, these large hooks were not present in a small specimen, indicating it

658-490: 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

705-413: Is composed of three parts. Going from arms to tip, these are the tongue-shaped pro-ostracum; the conical, chambered phragmocone ; and the spear-shaped guard at the very tip. The guard is attached to the phragmocone in a socket called the alveolus. The cone, in life, would have been encased in muscle and connective tissue . They had calcite guards, and aragonite pro-ostraca and phragmocones, though

752-411: Is volatile with no clear consensus. Coleoidea is sometimes divided into Neocoleoidea (containing all modern cephalopods) and Paleocoleoidea (containing Belemnoidea ), so belemnites would be a sister group of modern cephalopods. However, this grouping is probably paraphyletic —it does not contain a common ancestor and all its descendants—and, thus, invalid. According to some authors, belemnites were

799-655: The Monteith Formation in northeastern British Columbia . It rests disconformably on Triassic units in the west, and unconformably on upper Paleozoic units such as the Schooler Creek Group and the Montney Formation farther east. The Fernie Formation has the following subdivisions from top to base: Sundance Sea The Sundance Sea was an epeiric sea that existed in North America during

846-484: The Triassic–Jurassic extinction event . They may have laid between 100 and 1,000 eggs. Some species may have been adapted to speed and swam in the turbulent open ocean , whereas others resided in the calmer littoral zone (nearshore) and fed off the seafloor. The largest belemnite known, Megateuthis elliptica , would have measured up to 3.11 metres (10.2 ft) in total body length. Belemnites were coleoids ,

893-624: The clade Belemnoidea and included the families Belemnitidae , Asteroconites , and Xiphoteuthis . The guard—also known as the rostrum, scabbard, gaine, and sheath —is the part of the animal most likely to be fossilized. Guards are difficult to distinguish at the species level, and, consequently, synonyms are common and inflate the group's apparent diversity. Preserved hooks can be used to distinguish belemnite species as each species has unique hook shapes. However, scolecodont segmented worm fossils have been mistaken for belemnite hooks and vice versa. Preserved fossil guards are used to measure

940-735: The longitude of Calgary . The formation is exposed in outcrops in the Kootenay region of southeastern British Columbia , in the foothills and front ranges of the Canadian Rockies in southwestern Alberta, and as far north as the Peace River Country in northeastern British Columbia. The Fernie Formation is conformably overlain by the Morrissey Formation in the south, by the Nikanassin Formation in central Alberta and by

987-450: The 4th and 3rd century BCE , in his book De Animalibus Quæ Dicuntur Invidere who described it as lyngurium , lynx urine which had been buried and solidified. Pliny the Elder , in the first century CE, did not believe in lyngurium and called the gemstone a belemnite for the first time—though not recognizing it as a fossil. The name is from Ancient Greek βέλεμνον bélemnon meaning dart for

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1034-417: The Jurassic progressed. This was probably due to pressure to become more streamlined and increase swimming efficiency, coevolving with increasingly faster predators and competitors. Their early evolution and apparent abundance were likely important in reconstructing marine ecosystems after the Triassic–Jurassic extinction event , providing an ample food source for marine reptiles and sharks. Belemnoidea, as

1081-402: The Sundance Sea. Crinoids and bivalves would have dotted the seafloor. Ophthalmosaurus , a large 20-foot (6 m) long ichthyosaur , swam in the seas using its large, long jaws to catch belemnite 'squid'. Pantosaurus , a 15–20 foot (4.5–6 m) long cryptoclidid plesiosaur , went after the easier-to-catch fish. The largest marine reptile in the Sundance Sea was Megalneusaurus ,

1128-470: The ancient isotopic signature of the waters the individual inhabited in life, which gives information on the climate, habitat, and carbon cycle . Belemnites were cephalopods . Having no outer shells, they are classified into the subclass Coleoidea. In 1994, American geologist Peter Doyle defined Coleoidea as composed of three superorders: Decapodiformes (squid and cuttlefish ), Octopodiformes (octopuses), and Belemnoidea; with Belemnoidea containing

1175-599: The east during the deposition of the lower and middle units of the Fernie, where the coarser facies occur in the eastern part of the formation. In the uppermost Fernie, the coarsest material is found in the west, however, indicating a shift to sources in the west and south. The Fernie Formation is composed primarily of brown and dark gray to black shales that range from massive with conchoidal fracture to laminated and highly fractured or papery. Phosphatic sandstone and limestone , including cherty limestone , occur locally in

1222-489: The guard's shape. Subsequent authors either considered it to be lyngurium or amber . The first mention of a belemnite representing a fossil was made in 1546 by German mineralogist Georgius Agricola , and subsequent authors gave several hypotheses to its nature in life, including them being shellfish , sea urchin spines, sea cucumbers , coral polyps , or some internal shell. In 1823, English naturalist John Samuel Miller classified belemnites as cephalopods, comparing

1269-473: The hectocotyli feature a pair of enlarged hooks—mega-onychites—to latch onto the female at a safe distance to prevent getting stuck with one of her hooks. Like squid, the positioning of the mega-onychites could have been either at the tip or origin of the arm depending on the species. Copulation probably involved the male depositing spermatophores into the female's internal mantle chamber. Like other cephalopods, belemnites may have laid floating egg masses, and

1316-513: The largest among belemnites, measuring 60 to 70 cm (24 to 28 in) in length and up to 50 mm (2.0 in) in diameter. The Cretaceous Neohibolites is one of the smallest known with a guard length of around 3 cm (1.2 in). In the New Zealand Belemnopsis , four major annual growth stages were preserved in the guard, giving belemnites a lifespan of about three to four years. The mesohibolitid belemnites, using

1363-473: The lower parts of the formation ; siltstone , sandstone , coquinas and oolitic limestone interbeds can occur in the center; glauconitic sandstone and siltstone can be present in the upper parts. The Fernie Formation reaches a maximum thickness of 400 metres (1,310 ft) near Mount Allan in Alberta, and typically is about 70 to 150m (230 to 492 ft) thick. It thins toward the east, disappearing at about

1410-421: The material. The chitinous hooks are subdivided into three sections: The base - which can be either flat or concave - the shaft - which projects either upward at an incline either straight or bent - and the uncinus - which can be hook- or saber -like. Overall, they were fish-hook shaped, and probably only the uncinus was exposed. Different hook shapes were probably specialized for certain tasks, for example,

1457-641: The mid-to-late Jurassic Period of the Mesozoic Era. It was an arm of what is now the Arctic Ocean , and extended through what is now western Canada into the central western United States. The sea receded when highlands to the west began to rise. The Sundance Sea did not occur at a single time; geological evidence suggests that the Sea was actually a series of five successive marine transgressions —each separated by an erosional hiatus —which advanced and receded from

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1504-529: The middle Jurassic onward. The terrestrial sediments of the Morrison Formation —eroded from rising highlands to the west—were deposited on top of the marine Sundance sediments as the sea regressed for the last time late in the Jurassic. The Sundance Sea was rich in many types of animals. Gryphaea was extremely common, and shark teeth have been found. In addition to fish , belemnites and to an extent ammonites have been found in sediments from

1551-437: The midsection of the arm, possibly because the midsection is where maximum power could be exerted when grabbing, or bigger hooks on the extremities of the arm increased the risk of losing the arm. Having two rows of hooks covering the entire breadth of the arm, a belemnite could have had between 100 and 800 hooks in total. Some hooks have a spur just above the base, but this may be a distortion from fossilization or preparation of

1598-411: The newly discovered phragmocone remains to that of a nautilus, and concluding a resemblance to Sepia cuttlefish . He also erected the genus Belemnites with 11 species. This classification was confirmed when the first impressions of belemnite soft body anatomy were described by English paleontologist Richard Owen in 1844. In 1895, German paleontologist Karl Alfred Ritter von Zittel organized

1645-570: The octopus-like Prototeuthina and the belemnoid Phragmoteuthida . However, there is a dubious Permian occurrence, the Palaeobelemnopsidae , reported from Southern China. By the Early Jurassic, belemnites were probably quite common, having spread out into the western Laurasian coasts as well as Gondwanan waters to the south. Guard shapes in the early Jurassic ranged from conical to spearheaded but spearheaded became more prevalent as

1692-400: The orders Aulacocerida , Diplobelida , and Belemnitida. Also, the order Phragmoteuthida is sometimes believed to be a sister group to Belemnoidea, but Doyle considered it to be a stem-group to Decapodiformes and Octopodiformes. † Aulacocerida † Diplobelida † Belemnitida † Phragmoteuthida Octopodiformes Decapodiformes However, the higher classification of cephalopods

1739-856: The phragmocone was large, implying a small mantle cavity and thus less jet propulsion efficiency. Like some modern squid, belemnites may have mainly used large fins to coast along currents . Two Acanthoteuthis specimens with preserved soft anatomy elements had a pair of rhomboid fins near the top of their guards; however, the specimens had different-sized fins, possibly owing to sexual dimorphism , age, or distortion during fossilization. These specimens appeared to have had similar adaptations to modern squid for speed and may have been able to reach similar maximum speeds of 1.1 to 1.8 km/h (0.68 to 1.12 mph) like modern migrating Todarodes flying squid . Belemnites had 10 hooked arms of, more or less, equal length with suckers. The hooks were rarely larger than 5 mm (0.20 in), and increased in size toward

1786-630: The rest of the world by the Pliensbachian stage 190 mya. However, the 2012 discovery of early Asian forms classified into the family Sinobelemnitidae —now moves this to around 234 mya in the Carnian stage of the Late Triassic . Belemnites probably originated in the Asian part of the Panthalassic Ocean around the eastern coasts of the ancient continent of Laurasia in a cephalopod radiation , alongside

1833-529: The same methods, had a lifespan of about a year. In Megateuthis , the guard was demonstrated to have fully developed after one or two years, and growth spurts followed the lunar cycle . Belemnite guards have sometimes been found with fractures with signs of healing. It has been interpreted in the past that these are evidence of digging, with belemnites using their guard to dig up prey on the seafloor; however, belemnites are now generally interpreted to have been open ocean predators. A deformed, zigzag-like guard of

1880-427: The side likely stemming from a parasitic infection. A Hibolithes guard shows a large ovoid bubble near the base, likely deriving from a parasitic cyst . A Goniocamax guard has several blister-like formations, thought to have come from a polychaete flatworm infection. The calcitic guards were desirable habitats for boring parasites indicated by the diversity of trace fossils left on some guards, including

1927-426: The skin was likely thin and slippery. The eyeballs were likely thicker, stronger, and more convex than in other cephalopods. The mantle cavity of cephalopods serves to contain the gills, gonads , and other organs; also, water is siphoned into and expelled out of the mantle cavity via a tube opening near the arms of the animal, the hyponome , for jet propulsion . Though the hyponome was well-developed in belemnites,

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1974-549: The sponge Entobia , worm Trypanites , and barnacle Rogerella . Belemnites, being coleoids , derive from the orthoconic (conical) Devonian belemnoid order Aulacocerida , which, in turn, is derived from the Devonian Bactritida . Belemnites were traditionally thought to have evolved in northern Europe in the Hettangian stage of the Early Jurassic 201.6–197 million years ago (mya) and later spread to

2021-406: The surface, though modern cephalopods generally stay completely submerged. Though unlikely, it is possible fossilization increased the perceived density of the guard, and it may have been up to 20% more porous in life. Fins may have been attached to the guard, or the guard may have lent support for large fins. Including arms, guards could have accounted for one-fifth to one-third of the total length of

2068-465: The tip of the phragmocone beneath the guard is a tiny, cup-like protoconch , the remains of the embryonic shell. The dense guard probably served to counterbalance the weight of the soft parts in the mantle cavity near the arms on the opposite end of the animal, analogous to the camera of nautiloids . This would have allowed the animal to move horizontally through the water. The guard may have also served to cut through waves while swimming at

2115-494: The world. Much like in cuttlefish, nautiluses, and ammonites , the number and successive size of the chambers of the phragmocone are used to analyze the growth of an individual over their life. Successive belemnite chambers tend to increase in size exponentially. Unlike other cephalopods, there is no decreasing trend of chamber size in the earliest stages. The decreasing trend generally coincides with hatching, meaning embryonic belemnites had no or few chambers and hatched only with

2162-555: Was either a juvenile—and the development of different hooks coincided with a difference in prey selection - or the specimen was a female and the hooks were used by males for male-on-male combat or during copulation. In modern hook-bearing squid species, only matured males have hooks, indicating a reproductive purpose. It is possible the hooks, being analogous to suckers, could move. The males, like in modern squid, probably had one or two hectocotyli - long, modified arms used in copulation or combat with other males. Instead of several hooks,

2209-410: Was probably the center of buoyancy , and so was positioned directly above the center of mass for stability purposes. Concerning buoyancy, belemnites may have behaved much like modern ram's horn squid , having the chambers of the phragmocone flooded and slowly releasing more seawater via the siphuncle tube as the animal increases in size and weight over its lifetime to maintain neutral buoyancy . At

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