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| {{WikiProject Dinosaurs Collaboration}} | |||
| {{Taxobox | |||
| | color = pink | |||
| | name = ''Spinosaurus'' | |||
| | fossil_range = mid ] | |||
| | image = spinosaurus.jpg | |||
| | image_width = 200px | |||
| | regnum = ]ia | |||
| | phylum = ] | |||
| | classis = ] | |||
| | superordo = ] | |||
| | ordo = ] | |||
| | subordo = ] | |||
| | superfamilia = ] | |||
| | familia = ] | |||
| | subfamilia = ] | |||
| | genus = '''''Spinosaurus''''' | |||
| | genus_authority = ], 1915 | |||
| | subdivision_ranks = ] | |||
| | subdivision = | |||
| *''S. aegyptiacus'' (]) | |||
| *?''S. marocannus'' <small>Russell, 1996</small> | |||
| }} | |||
| '''''Spinosaurus''''' (meaning 'spine lizard') was a ] of ] ] that lived in what is now ], from the ] to early ] ] of the ] ], about 95 to 93 ] years ago. It is unclear whether there are one or two species. The best known is ''S. aegyptiacus'' from ], though a second species (''S. marocannus'') has been recovered from ]. | |||
| The distinctive "spines" of these animals (long extensions of the ]e) grew up to 2 m (6.6ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some have suggested they were covered in muscle and formed a hump or ridge. According to a ] by paleontologist ] of the Civic Natural History Museum in ] and his colleagues in 2006, it is the largest of all ] ]s, even larger than '']'' and '']''. If the estimates are correct, ''Spinosaurus'' would be the longest ], measuring 15 to 17.4 ] (49.2 to 57.1 feet) long, around 6 meters (20 feet) tall, and reached ]s up to 9 ]s.<ref name="dalsassoetal06">dal Sasso, C., S. Maganuco, E. Buffetaut and M. A. Mendez (2006). "New information on the skull of the enigmatic theropod ''Spinosaurus'', with remarks on its sizes and affinities." ''Journal of Vertebrate Paleontology'', '''25'''(4): 888-896.</ref> | |||
| ''Spinosaurus'' gives its name to a family of dinosaurs, the ], of which other members include '']'' (probably synonymous with ''Irritator'') and '']'' from ], '']'' from southern ], '']'' from ] in central ], and '']'', known from fragmentary remains in ]. | |||
| ==Description== | |||
| Although ''Spinosaurus'' is well-known to dinosaur enthusiasts due to its unusual features, it is mostly known from remains that have been destroyed, aside from a few more recently discovered teeth and skull elements. Jaw and skull material published in 2006 show that it had one of the longest skulls of any carnivorous dinosaur, estimated at about 175 ] (5.7 ]).<ref name="dalsassoetal06"/> | |||
| Aside from its 'sail', notable characteristics of ''Spinosaurus'' include: | |||
| * A long, narrow snout, similar to other Spinosaurids and, like them, filled with conical teeth. | |||
| * One enlarged, hook-like claw on each of its front limbs, perhaps for catching fish. | |||
| * Relatively short legs and long 'arms', leading some paleontologists to suggest it may have been quadrupedal, rather than strictly bipedal (though it was undoubtedly capable of at least facultative bipedality). | |||
| Much of this is speculation based on ''Baryonyx'' and other spinosaurids, as no limb material has ever been attributed to ''Spinosaurus'' itself. | |||
| ==Discovery and species== | |||
| Originally found in the ] of ] in ], it was named by German paleontologist ] in ].<ref name = "Stromer15">Stromer E (1915) Wirbeltier-Reste der baharije-Stufe (unterstes Cenoman).3. Das Origianl des Theropoden ''Spinosaurus aegyptiacus'' nov. gen. et nov. spec. ''Abhandl. K. Bayer. Akad. Wiss. Math.-phys. Kl.'' '''28''': 1-32</ref> Some of the fossils were damaged during transport back to the ], ], ] and the remaining bones were completely lost due to Allied ] in ]. | |||
| Two species of ''Spinosaurus'' have been named: ''Spinosaurus aegyptiacus'' ("Egyptian spine lizard") and ''Spinosaurus marocannus'' ("Moroccan spine lizard"). ''S. marocannus'' was originally described by Russell as a new species based on the length of its neck vertebrae. However, several later authors considered the length of the neck vertebrae to be variable from individual to individual and therefore consider ''S. marocannus'' to be a synonym of ''S. aegyptiacus'' . | |||
| Five partial specimens of ''Spinosaurus'' have been found, the first having been destroyed during ] (luckily, detailed drawings and descriptions of the specimen remain). The probable size of these individual spinosaurs can be estimated using comparison to known material from other ] dinosaurs. In 2002, some dentary material from Tunisia which is very similar to existing material of ''S. aegyptiacus'' was described.<ref name = "BufOua02">Buffetaut, E & Ouaja, M (2002) A new specimen of ''Spinosaurus'' (Dinosauria, Theropoda) from the Lower Cretaceous of Tunisia, with remarks on the evolutionary history of the Spinosauridae. ''Bulletin de la Société Géologique de France'' '''173''' 415-421; DOI: 10.2113/173.5.415</ref> | |||
| * '''IPHG 1912 VIII 19''' (Stromer, 1915)<ref name = "Stromer15"/> (destroyed during allied bombing in WWII) | |||
| ** '''Size:''' 17.4 m, 12-19 tons (subadult) | |||
| ** '''Material:''' (skull ~1.45 m) maxillary fragment, incomplete dentary (mandible ~1.34 m), nineteen teeth (62, 126 mm), two incomplete cervical vertebrae, seven dorsal vertebrae (190-210 mm), dorsal ribs, gastralia, eight caudal centra. | |||
| * '''CMN 50791''' (Russell, 1996) | |||
| ** '''Material:''' mid cervical vertebra (195 mm), anterior dorsal neural arch, anterior dentary, mid dentary. | |||
| ** '''Note:''' ] of ''Spinosaurus marocannus''. | |||
| * '''MNHN SAM 124''' (Taquet and Russell, 1998) | |||
| ** '''Size:''' ~17 m, ~11-18 tons (adult) | |||
| ** '''Material:''' (skull ~1.42 m) partial premaxillae, partial maxillae, vomers, dentary fragment. | |||
| * '''Office National des Mines nBM231''' (Buffetaut and Ouaja, 2002)<ref name = "BufOua02"/> | |||
| ** '''Material:''' anterior dentary. | |||
| * '''MSNM V4047''' (Dal Sasso ''et al.'', 2006)<ref name="dalsassoetal06"/> | |||
| ** '''Size:''' ~21 m, ~20-32 tons | |||
| ** '''Material:''' (skull ~1.75 m) premaxillae, partial maxillae, partial nasals | |||
| In 2003, Rauhut suggested that Stromer's ''Spinosaurus'' holotype was a ], consisting of dorsal vertebrae from a ] similar to '']'' and a dentary from a large theropod similar to '']''.<ref name ="Rauh03">{{cite journal | author = Rauhut, O.W.M. | year = ] | title = The interrelationships and evolution of basal theropod dinosaurs | journal = Special Papers in Palaeontology | volume = 69 | pages = 1-213}}</ref> This analysis, however, has been rejected by dal Sasso and most other researchers. | |||
| ==Paleobiology== | |||
| ''Spinosaurus'' has some unusual features which have been the subject of debate thus far: | |||
| ===Size=== | |||
| Since its discovery, ''Spinosaurus'' has held the record for longest, and possibly largest, theropod dinosaur (though this fact did not reach the public consciousness until its depiction in the film '']'' and the description of a new specimen in 2006). Both Huene<ref name = "vH26">von Huene, F. R. (1926). "The carnivorous saurischia in the Jura and Cretaceous formations principally in Europe." ''Rev. Mus. La Plata'', '''29''', 35-167</ref> and Glut<ref>Glut, D.F. (1982). ''The New Dinosaur Dictionary''. Citadel Press, Secaucus, New Jersey.</ref> listed it as the most massive theropod in their surveys, at upwards of 6 tons in weight and 15 meters (50 feet) in length. In 1988, Paul also listed it as the longest theropod at 15 meters (50 feet), but gave a lower mass estimate.<ref name = "Paul88">Paul, G.S. (1988). ''Predatory Dinosaurs of the World.'' New York: Simon and Schuster. 464 pp.</ref> The most recent estimates, based on new specimens list ''Spinosaurus'' at 16 - 18 metres (53.3 to 60 feet) long and 7.5 - 9 tons in weight.<ref name="dalsassoetal06"/> At least one survey, as-yet unpublished, suggest that ''Spinosaurus'' reached sizes of 12 - 19 tons in weight. These high-end weight estimates were based on the fact that the vertebrae of ''Spinosaurus'' are unusually massive compared to theropods of comparable size (implying an extremely large overall mass), and that the ] specimens are apparently sub-adult. However the author of these estimates has recently reduced them to similar sizes suggested by dal Sasso et al. | |||
| ===Sail=== | |||
| ''Spinosaurus'' sails were unusual, although other dinosaurs of the same time and area, namely the ] '']'' and the ] ''],'' might have developed a similar structural adaptation of their dorsal vertebrae (however, this is not uncontroversial; see the articles about these animals for more information). The sail is possibly ] (not ]) to that of the ] ], '']'', which lived before the dinosaurs even appeared (these similarities are presumably due to ]). | |||
| The purpose of these sails is uncertain; scientists have proposed several hypotheses: | |||
| ] | |||
| *'''Heat regulator'''. If the sail contained abundant blood vessels, the animal could have used the sail's large surface area to absorb heat. This would imply that the animal was only partly warm-blooded at best and lived in climates where nighttime temperatures were cool or low and the sky usually not cloudy. It is thought that ''Spinosaurus'' and '']'' both lived in or at the margins of an earlier version of the ], which could explain this. It is also possible that the sail was used to radiate excess heat from the body, rather than to collect it. Large animals, due to the relatively small ratio of surface area of their body compared to the overall volume (]), face far greater problems of dissipating excess heat at higher temperatures than gaining it at lower. Sails of these dinosaurs added considerably to the skin area of the body, with minimum increase of volume. Furthermore, if the sail was turned away from the sun, or positioned at a 90 degree angle towards a cooling wind, the animal would quite effectively cool itself in the warm climate of Cretaceous Africa. | |||
| *'''Sexual display'''. Elaborate body structures of many modern-day animals usually serve to attract members of opposite sex during mating. It is quite possible that the sails of these dinosaurs were used for courtship, in a way similar to a ]'s tail. If this was the case, the sails may have been brightly colored, but this is purely speculative. | |||
| *'''Intimidating device'''. The sail was possibly used to intimidate rivals or frighten enemies, making the animal appear to be bigger than it was. The dinosaur could display its sail as a final warning signal, before it would resort to open attack, like modern-day ]s use their tail. | |||
| Finally, since things in nature rarely develop for a singular reason, it is quite possible that the sail combined all these functions, acting normally as a heat regulator, becoming a courting aid during the mating season, being used to cool itself and, on occasions, turning into an intimidating device when an animal was feeling threatened. Conjecture may even allow that the sail may have changed colour, during any of these functions. | |||
| ===Feeding ecology=== | |||
| It is unclear whether ''Spinosaurus'' was primarily a cursorial predator or a fisher, as indicated by its elongated jaws, conical teeth and raised nostrils. The only direct evidence for spinosaur diet comes from related ]an and ]n species. '']'' was found with both fish scales and bones from juvenile '']'' in its stomach, while a tooth embedded in a South American ] bone suggests that spinosaurs occasionally preyed on these flying archosaurs.<ref>Buffetaut, E., D. Martill & F. Escuillié (2004). "Pterosaurs as part of a spinosaur diet." ''Nature'', '''430''': 33.</ref> ''Spinosaurus'' was likely to have been a more generalized and opportunistic predator, possibly a Cretaceous equivalent of large ]s, being biased toward fishing, though it undoubtedly scavenged and took many kinds of small-to medium-sized prey.<ref name = "Paul88"/> | |||
| ==In popular culture== | |||
| ]''.]] | |||
| ''Spinosaurus'' was featured as the main antagonist in the 2001 film '']''. It was portrayed as larger and more powerful than '']'', in a scene depicting a battle between the two resurrected predators where ''Spinosaurus'' emerges victorious by snapping the tyrannosaur's neck. In reality, no such battle could ever have taken place, since ''Spinosaurus'' and ''Tyrannosaurus'' lived thousands of miles and millions of years apart. <!--Please do not add in stuff about why the Rex should have won in JP3. We're trying to keep things as objective as possible by not mentioning the Rex's jaw force, seeing as we're just mentioning the facts shown in the movie and don't know how powerful the Spino was . Thanks for leaving it alone.--> ''Spinosaurus'' did, however, share its habitat with two other theropods that equalled or exceeded ''Tyrannosaurus'' in size: the massive ] '']'', and the large but relatively lightweight '']''. | |||
| After appearing in '']'', ''Spinosaurus'' was featured in a wide variety of merchandise related to the ''Jurassic Park'' films, including a number of video games such as '']'' from ]. ''Spinosaurus'' was also featured in the television documentary '']''. | |||
| ==References== | |||
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