Spinosaurus (meaning "spined lizard") is an extinct genus of large spinosaurid theropod dinosaur that inhabited early to middle Cretaceous (Cenomanian); albeit there are significant discoveries that state the theropod could lived as long as Early Campanian of Late Creteceous[1], Northern Africa, states such as Morocco, Egypt, Tunusia, Libya; approximately 99 to 93.5 (although the theropod could survived as much as around 80 million years)[1] million years ago.
The type and only genus is S. aegyptiacus (meaning "spined lizard from Egypt"), though there is a possible specimen from Morocco that could prove another species, being S. maroccanus.
The first known remains were found in Egypt by the German paleontologist Ernst Stromer in 1912, then described and named in 1915. The original holotype remains were destroyed in World War II in a bombing raid, in 1944 by the British RAF.
Fortunately, additional material from other individuals have been found and come to light in the 21st century, though lots of jaw pieces and other material are sold and kept in private collections, lost to science.
The contemporary spinosaurid genus Sigilmassasaurus has been synonymized by some authors with S. aegyptiacus, and more recently others proposed it to be a distinct taxon yet again with a new mid-cervical vertebra. However, recent scientific publication does not synonymize Sigilmassasaurus with Spinosaurus.[2]
Paleontologists David W.E. and Thomas R. Holtz, Jr. conclude that Spinosaurus was more akin to a generalist wading animal species instead of highly specialized aquatic species in a recent paper. The interpretations arise from inconsistencies with the pursuit predator model by Ibraham et.al.[3][4][5] Their findings and conclusions are further supported and solidified by additonal research and publications.[6][7][8][9]
Spinosaurus were amongst the largest known of all carnivorous dinosaur theropods, even larger than Tyrannosaurus rex and Giganotosaurus, recent estimates put the length at 13.6 - 14.7 - 15 meters and analyzed a mass of 7.3 to 8.5 tonnes (for the larger specimens); this puts Spinosaurus in the current top 6 most massive theropods.
History[]
The first remains have been officially discovered in Egypt in 1912 and named by paleontologist Ernst Stromer, in April 24th, 1994 however, the original remains were destroyed in World War II. The name; Spinosaurus means, spine lizard in Latin. It gets its name from the sail on its Dorsal vertebrae.[10][11]
Discovery and naming[]
Naming of species[]
Plate I in Stromer (1915) showing S. aegyptiacus holotype elements
The first described remains of Spinosaurus were found in the Bahariya Valley of Egypt in 1912, and were named by German paleontologist Ernst Stromer in 1915.[12] Fragmentary additional remains from Bahariya, including vertebrae and hindlimb bones, were designated by Stromer as "Spinosaurus B" in 1934.[13]
S. aegyptiacus
S. marocannus
S.? sp.
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Stromer considered them different enough to belong to another species, and this has been borne out; with the advantage of more expeditions and material, it appears that they either pertain to Carcharodontosaurus[14] or to Sigilmassasaurus.[15] Some of the Spinosaurus fossils were damaged during transport back to the Deutsches Museum, in Munich, Germany, and the remaining bones were completely lost due to Allied bombing in 1944.[16]
Two species of Spinosaurus have been named: Spinosaurus aegyptiacus (meaning "Egyptian spine lizard") and Spinosaurus marocannus (meaning "Moroccan spine lizard"). S. marocannus was originally described by Dale Russell as a new species based on the length of its neck vertebrae.[15] Later authors have been split on this topic, some considering the length of the vertebrae to be variable from individual to individual and therefore regarding S. marocannus as invalid or a synonym of S. aegyptiacus,[14][17][16] and others retaining it as valid.[18]
Specimens[]
Stromer's original reconstruction of S. aegyptiacus, 1915
Digital skeletal reconstruction of Spinosaurus, showing known bones based on the holotype (red), proposed neotype (blue), and referred specimens (yellow), according to Sereno and colleagues
Six partial specimens of Spinosaurus have been described. The probable size of these individual spinosaurs can be estimated using comparison to known material from other spinosaurid dinosaurs. The estimates below are based on the Theropod Database[17] and Dal Sasso et al, 2005.[16]
IPHG 1912 VIII 19, described by Stromer in 1915, from the Bahariya Formation, was the holotype.[12] This specimen, from a subadult individual, was destroyed in World War II. However, detailed drawings and descriptions of the specimen remain. The individual is estimated to have been around 14 meters (46 ft) long and to have weighed about 6.7 tonnes (7.4 short tons). The material consisted of a maxilla (upper jaw) fragment, an incomplete dentary (lower jaw) measuring 75 centimetres (30 in) long, (the skull is estimated to have been 1.45 meters (5 ft) long with a mandible approximately 1.34 meters (4 ft) long), nineteen teeth, two incomplete cervical vertebrae, seven back vertebrae, dorsal ribs, gastralia, and eight caudal centra. This was the specimen that Rauhut thought was chimeric.
S. marocannus jaw fossil, Muséum national d'Histoire naturelle, Paris
CMN 50791, described by Russell in 1996, from the Kem Kem Beds of Morocco, is the holotype of Spinosaurus marocannus. The material it is based on includes a mid-cervical vertebra which is 19.5 centimetres (7.7 in) long, an anterior dorsal neural arch, an anterior dentary, and a mid-dentary. MNHN SAM 124, described by Taquet and Russell in 1998 from Algeria, consists of partial premaxillae, partial maxillae, vomers, and a dentary fragment. They came from an individual estimated to have been about 14 meters (46 ft) long and to have weighed about 6.7 tonnes (7.4 short tons). The skull is estimated at approximately 1.42 meters (5 ft) long. Office National des Mines nBM231, described by Buffetaut and Ouaja in 2002, consists of an anterior dentary from the Chenini Formation of Tunisia, which is very similar to existing material of S. aegyptiacus.[19]
Comparison between the snouts MNSM V4047 and MNHN SAM 124, holotype of S. maroccanus
The Dal Sasso specimen of S. aegyptiacus, 2008
MSNM V4047, described by Cristiano Dal Sasso of the Civic Natural History Museum in Milan and his colleagues in 2005 from the Moroccan Kem Kem Beds, consists of premaxillae, partial maxillae, and partial nasals, which together measure 98.8 centimetres (38.9 in) long. The massive skull is estimated at 1.75 meters (6 ft) long, and the entire animal is estimated to have been around 16 to 18 metres (52 to 59 ft) in length and weighed around 7 to 9 tonnes (7.7 to 9.9 short tons). UCPC-2, also described by Dal Sasso et al. in 2005, consists of a 'fluted crest' from the region in front of the eyes.[16]
Other known specimens consist mainly of very fragmentary remains and scattered teeth. For example, teeth from the Echkar Formation of Niger have been referred to S. aegyptiacus.[20] Possible material belonging to Spinosaurus has also been reported from the Turkana Grits of Kenya and the Cabao Formation of Libya (which dates to the Hauterivian stage), though the assignment of the later to the genus Spinosaurus is tentative.[21][22]
Notable Specimens[]
- "EMB1MORO": A specimen which has been suggested to be a Spinosaurus embryo, given the informal name "S. dorsojuvencus" by C.E. Goo, who is known for the Petrified Embryology series. The author suggests cervical scutes are present. However, the specimen, collected in Morocco, is likely not a Spinosaurus, and probably not even animal remains at all. Most paleontologists dismiss these, as they appear to be a product of pareidolia rather than genuine fossils[23].
- NMC 41852 or NMC 42852 : a humerus, claimed by Cau et. al to be comparable to Limaysaurus and placed it as a a rebbachisaur, later determined by Ibrahim et al. (2014) to be a spinosaur affinity. If its assignment to Spinosaurus is confirmed, it would extend the weight limit of the theropod even more, 10+ tons.[24]
Description[]
The most notable feature of Spinosaurus was a row of tall spines that adorned its back, which are believed to have supported a sail in life, not unlike Ouranosaurus and the non-dinosaur Dimetrodon. It has been theorized that this "sail" would have been used for display purposes, to attract mates and intimidate rival spinosaurs.
Spinosaurus, like its relatives Baryonyx and Suchomimus, had sleek jaws like those of species of long snouted crocodilians (such as orinoco crocodiles and Australian freshwater crocodiles) and gharials, along with a long neck, both adaptions suited for seizing aquatic prey, which comprised a part of their diets (evidence exists that suggests spinosaurids also ate other animals, including pterosaurs and other dinosaurs).
Spinosaurus, as it was commonly depicted prior to 2014
Also like Baryonyx and Suchomimus, it bore massive, hook-like claws on its hands.
In 2020, it was described that Spinosaurus possessed a somewhat paddle-like tail, suggested by the authors of the paper to have been for underwater propulsion. It has also been suggested that the tail may have acted as a secondary display structure.
Size[]
Size comparison of selected giant theropod dinosaurs, S. aegyptiacus in red
Since its discovery, Spinosaurus has been a top contender for longest and largest theropod dinosaur, though this fact did not reach the public consciousness until its depiction in the film Jurassic Park III and the description of a new specimen in 2005. Both Friedrich von Huene[25] and Donald F. Glut,[26] decades apart, listed it as among the most massive theropods or the most massive in their surveys, at upwards of 6 tons in weight and 14.7 meters (49 ft) in length. In 1988, Gregory S. Paul also listed it as the longest theropod at 14.7 meters (49 ft), but gave a lower mass estimate.[27] More recent estimates, based on new specimens, list Spinosaurus at 16 to 18 meters (52 to 59 ft) long and 7 to 9 tonnes (7.7 to 9.9 short tons) in weight.[16]
Estimated size of the largest known, holotype, neotype, and smallest known specimen with a human
François Therrien and Donald Henderson, in a 2007 paper using scaling based on skull length, challenged previous estimates, finding the length too great and the weight too small. Their estimates include a length of 12.6 - 14.3 meters and a mass of 12 to 20.9 tonnes (13 to 23 short tons).[28] Their study has been criticized for the choice of large theropods used for comparison (most of the skeletons of large theropods used to set the initial equations are of tyrannosaurids and carnosaurs, which have a different build than spinosaurids) and for issues relating to their spinosaurid skull reconstructions.[29] Resolution awaits more complete remains.
Legs[]
Life restoration of Spinosaurus as a largely aquatic animal
In 2014, material was described revealing that its legs were much shorter than those of its relatives, to such a degree that some have proposed that it was restricted to a quadrupedal gait when on land; others have suggested that it assumed a stance not unlike that of a pangolin. The find and the Spinosaurus specimen in question (named FSAC-KK 11888) have been questioned - some have proposed that the legs belong to a younger Spinosaurus than the rest of the specimen in the Ibrahim study (which would mean that it is chimeric, a mix of separate spinosaurs). Regardless of whether or not FSAC-KK 11888 is a chimera, Spinosaurus still would have had significantly proportionately shorter legs than its relatives in life.
Sail[]
Reconstructed replicas of the holotype vertebrae, National Geographic Museum, Washington, D. C.
Spinosaurus sails were unusual, although other dinosaurs of the same time and area, namely the ornithopod Ouranosaurus and the sauropod Amargasaurus, 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 analogous (not homologous) to that of the Permian synapsid Dimetrodon, which lived before the dinosaurs even appeared; these similarities are due to parallel evolution. The sail may also have been more hump-like than sail-like; as noted by Jack Bowman Bailey most recently, spinosaur spines are not thin rods but broad front to back, rather like those of some types of buffalo, and so may have supported a thicker, fatty structure as opposed to a skin sail.[30]
Life restoration
The function of these sails is uncertain; scientists have proposed several hypotheses including heat regulation and display. In addition, such a prominent feature on its back could also make it appear even larger than it was, intimidating other animals. 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 Ouranosaurus both lived in or at the margins of an earlier version of the Sahara Desert, 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 (Haldane's principle), 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.[31]
Elaborate body structures of many modern-day animals usually serve to attract members of the opposite sex during mating. It is quite possible that the sails of these dinosaurs were used for courtship, in a way similar to a peacock's tail. Stromer speculated that males and females may have differed in the size of the neural spine.[12] If this was the case, the sails may have been brightly colored, but this is purely speculative.
Finally, it is quite possible that the sail combined 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.
Posture[]
Although traditionally depicted as a biped, it has been suggested since the mid-1970s that Spinosaurus was at least an occasional quadruped.[31][26] This has been bolstered by the discovery of Baryonyx, a relative with robust arms.[32] Bailey (1997) was sympathetic to a possible quadrupedal posture,[30] leading to new restorations of it as such.[32] This hypothesis has fallen out of favor, at least as a typical gait, though spinosaurids may have crouched in a quadrupedal posture.[33]
Classification[]
Specimen MNBH EGA1 which may belong to Spinosaurus
Spinosaurus gives its name to a family of dinosaurs, the Spinosauridae, of which other members include Baryonyx from southern England, Irritator and Angaturama (which is probably synonymous with Irritator) from Brazil, Suchomimus from Niger in central Africa, and possibly Siamosaurus, which is known from fragmentary remains in Thailand. Spinosaurus is closest to Irritator, which shares its unserrated straight teeth, and the two are included in the subfamily Spinosaurinae.[18] In 2003, Oliver Rauhut suggested that Stromer's Spinosaurus holotype was a chimera, composed of back vertebrae from a carcharodontosaurid similar to Acrocanthosaurus and a dentary from a large theropod similar to Baryonyx.[34] This analysis, however, has been rejected in recent papers.[18][16]
Restoration of various spinosaurids that did not live in the same time or space
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Paleobiology[]
1915 illustration of S. aegyptiacus dorsal vertebrae
Many have suggested that several of Spinosaurus's anatomical traits, including its unusually small hind legs and its possibly-webbed feet, were adaptations for swimming in deep water, a suggestion bolstered by the description of a Spinosaurus tail, which was thin, flexible and bore a "sail", and would very likely have been used as a means of propulsion like the tail of a crocodilian.[35][36] A 2022 paper bolstered the notion of a largely-aquatic Spinosaurus, indicating that it and one of its relatives, Baryonyx, possessed very dense bones, a trait found in several animals that aids their ability to dive underwater. The same paper found that another spinosaurid, Suchomimus, had less dense bones than Spinosaurus and Baryonyx and likely spent more of its time on land than either of its relatives. [37][38]
The proposed largely aquatic lifestyle of Spinosaurus has been contested. It has been suggested that Spinosaurus may have been too buoyant to dive properly and that it may have been an ineffective swimmer, and it has been noted that some Spinosaurus fossils have been excavated from locales that would have been far inland when the genus was still extant. Regardless of whether or not it was adapted for active underwater life, it has still been suggested that it would have spent much of its time in and around shallow water. [39]
Diet[]
Tooth from Morocco in various views
Its unclear that the Spinosaurus was whether a highly specialized piscivore (obligate fish eater) or a generalist carnivore. All known evidence for Spinosaurus dietary preferences, directly comes from the relative spinosauridae species, for example: Baryonyx had shown clear indication for generalist behavior, as one specimen's fossilized rib cage has been found to contain prehistoric species of fish, as well as the remains of a sub-adult Iguanodont, the iberian Baryonyx specimens have also found with direct association to Iguanodonts[40]; more examples include another spinosaurid, a more closer relative to Spinosaurus, the Irritator has been found, that either attacked, or ate a large pterosaur [41] and has been suspected to be a dominant predatory theropod of its environment. [42]
Additionally, there has been the discovery of another spinosaurid, a south Asian spinosaurinae known as Siamosaurus, has been directly consumed sauropods, it's uncertain that if this event was a scavenging situation or a true hunting.[43]
S. aegyptiacus head based on the 2005 reconstruction by Cristiano Dal Sasso
Dal Sasso and colleagues in 2009 reported results of X-ray computed tomography of the MSNM V4047 snout. As the foramina on the outside all communicated with a space on the inside of the snout, the authors had speculated that Spinosaurus had pressure receptors inside its snout used at the surface of the water to detect swimming prey species without seeing them, similar to how modern crocodilians with the same attributes catch fish.
Although this theory remains somewhat speculative with no further confirmation from any other publications.
A study in 2013 by Andrew R. Cuff and Emily J. Rayfield did concluded that bio-mechanical data suggests that Spinosaurus was not an obligate piscivore and that its diet was more closely associated with each individual's size. The characteristic rostral morphology of Spinosaurus allowed its jaws to resist bending in the vertical direction, but its jaws were poorly adapted with respect to resisting lateral bending compared to other members of this group Baryonychidae like Baryonyx and modern alligators, thus theorizing Spinosaurus could probably prey more regularly on aquatic prey than it did on terrestrial animals, although it is indeed considered predators of the former, too. Based on the direct paleontological fossil discoveries that Spinosaurus could be a generalist predator that hunted variety of prey item, like aquatic animals such as massive, multi-ton fish species; such as Mawsonia and Onchopristis, the inhabitant crocodylimorphs, as well as the terrestrial animals, such as larger pterosaurs, such as Alanqa, Anhanguera as well as, small to medium-sized dinosaurs, such as Ouranosaurus.
It is also possible that the Spinosaurus could be an additional scavenger, as well as a predator; similiar to most known modern carnivores.[44]
Aquatic habits[]
Restoration of Spinosaurus attacking the sawskate Onchopristis
The debate whether that the Spinosaurus was entirely aquatic, terrestrial or amphibious, switched between both habitats is to this day an active subject of debate.
The first thesis about the Spinosaurus, debuts that this theropod was likely a semi aquatic animal. This conclusion has been established by the 2014 fossil discoveries that gave Spinosaurus highly differentiated anatomical features [45], this conclusion has been bolstered by recent discovery as a highly elongated and dense tail, that might, potentially; helped animal to swim against the current of the Rivers. Studies of the tail, specimens recovered and analyzed by Ibrahim, Pierce, Lauder, and Sereno, in 2018 indicate that Spinosaurus had a keeled tail that was well adapted to propelling the animal through water.[46]
The second consensus that Spinosaurus was likely a terrestrial theropod arises from conducted research that refutes the semi-aquatic thesis for Spinosaurus, such as; a 2018 research, done by paleontologist Donald Henderson, the research has studying the buoyancy in lungs of crocodilians and comparing it to the lung placement in Spinosaurus, it was discovered that Spinosaurus could not sink or dive below the water surface. It was also capable of keeping its entire head above the water surface while floating, much like other non-aquatic theropods. Furthermore, the study found that Spinosaurus had to continually paddle its hind legs to prevent itself from tipping over onto its side, something that no known extant semi-aquatic animal species do not need to perform. The research conducted that Spinosaurus probably did not hunt completely submerged in water as previously hypothesized, but instead would have spent majority of its life on land or around water [47][48][49] however; these studies of the tail vertebrae of Spinosaurus refute Henderson's proposal that Spinosaurus mainly inhabited areas of land near and in shallow water and was too buoyant to submerge.
The elongated neural spines, which run to the end of the tail on both dorsal and ventral sides, indicate that Spinosaurus was able to swim in a similar manner to modern crocodilians. Through experimentation by Lauder and Pierce, the tail of Spinosaurus was found to have eight times as much forward thrust as the tails of terrestrial theropods like Coelophysis and Allosaurus, as well as being twice as efficient at achieving forward thrust. This discovery indicates that Spinosaurus may have had a lifestyle comparable to modern alligators and crocodiles, that this animal might have capable of remaining in water for long periods of time while hunting. [50] A more recent research concluded in 2022, by Ibrahim et al used bone density in a wealth of theropods to determine that Spinosaurus had bones about as dense as modern avians such as the penguins. In penguins, this specific structure is used to optimize buoyancy while diving. They entered it and other spinosaurs into a comprehensive dataset including crocodilians, ceteaceans, mosasaurs, sauropterygians (including ichthyosaurs), pinnipeds, placodontians, birds and pterosaurs but excluding Oxalaia and Sigilmassasaurus based on presumed synonymy. They found that it and possibly Baryonyx fall firmly into diver morphology and bear evidence of subaqueous feeding, where the latter was likely ancestral to Spinosauridae and likely secondarily lost in Suchomimus. The study was received well by others, although some paleontologists; like Donald M. Handerson remains skeptical about its conclusion.[51][52][53][54]
Additionally; there is also the research conducted at 2010, the scientists directly looked to the oxygen isotope ratios of spinosaurid bones, by comparing Isotope ratios from teeth from Baryonyx, Irritator, Siamosaurus, and Spinosaurus were compared with isotopic compositions from contemporaneous theropods, turtles, and crocodilians. The study found that, among theropods, spinosaurid isotope ratios were closer to those of turtles and crocodilians. However; Siamosaurus specimens tended to have the largest difference from the ratios of other theropods. Spinosaurus tended to have the least difference, this strongly suggests that the different species of Spinosaurids have had differentiated preferences for their habitats. Spinosaurus specimens show similar isotope ratios to other terrestrial theropods. This meant different species of spinosaurids have had differentiated habitat preferences. [55][56][57]
Although there are a number of counter thesis against the extended tail spines usage for propulsion, and in water; as well.[58][59]
A study and analysis conducted in 2021; indicated that the degree of aquatic habitation speculations attributed to Spinosaurus is not consistent, or valid, as well as the features attributed to this theropod indicate a more terrestrial lifestyle akin to wading avians such as the skua, pelicans, shoebills, giant petrels, storks or herons; instead of hyper specialized aquatic to semi aquatic species like dolphins and gharials. [60][61][62][63][64][65][66]
A study conducted in 2022 is criticized by Donald M. Handerson, as quoted: “I don’t doubt that Spinosaurus has very dense bones … [but] is it adding enough mass to help the animals sink?” asks Don Henderson, a paleontologist at Canada’s Royal Tyrrell Museum of Palaeontology whose 2018 study of Spinosaurus suggested that the animal would have been very buoyant.
“If you watch penguins swimming, as soon as they stop flapping their wings, they start to bob up to the surface,” Henderson says. “I just cannot see how Spinosaurus can stay underwater without extreme effort.”
Not every animal with dense bones lives an aquatic or even partially aquatic lifestyle. Elephants and extinct sauropod dinosaurs, for example, have dense limb bones to support their large weights. However, these weight-bearing “graviportal” bone structures visibly differ from the “osteosclerotic” ones that penguins and other diving creatures have. Highly dense bones can give animals a unique edge when it comes to staying in the water for extended periods without eliminating their ability to navigate dry terrain.
“While a penguin or a crocodile are capable of swimming and diving underwater, they are also able to walk on land,” Fabbri says. Though Spinosaurus and Baryonyx would have had an easier time hanging out in water than other dinosaurs, they also must have come up onto land from time to time. The first known fossil of Baryonyx contains fish scales as well as the bones of a juvenile plant-eating dinosaur—perhaps a sign of the predator’s opportunism both on land and in the water.
Flesh model of S. aegyptiacus used for a 2022 buoyancy study
Spinosaurid expert Tom Holtz, a paleontologist at the University of Maryland who wasn't involved with the study, says that the new data could have implications far beyond Spinosaurus and Baryonyx.[67]
The 2022 publication, in addition to Mr. Handerson is also criticized by Dr. David Hone; he said that the paper is: '' Apropos of absolutely nothing, Hone & Holtz (2021) "Standing in deeper water or even partially submerged (benefitting from reduced pneumaticity and pachyostotic bone) would allow them to forage for benthic prey". He also added; none of the points their publication and research has raised are mentioned and several claims we rebutted or even tested with data are repeated.[68][69]
Dave Hone also made a through analysis and documentary upload where here discusses about the Spinosaurids being more comparable to modern wading avians, instead of semi aquatic animals like crocodilians or hippos. He also cited that the Spinosaurus had an extremely anti-hydrodynamic body structure, where he commented on the fact that animal's nostrils are placed akin to more terrestrial animals, the structure of the sail being highly handicapping for swimming as wall as the tail's shape reminiscent of animals such as basilisk lizards and sailfin lizards and the tail's structure being ill fated for swimming.[70]
They have also published a paper referred to as: Spinosaurids as ‘subaqueous foragers’ undermined by selective sampling and problematic statistical inference. They have explained that the 2022 publication's inference and interpretation of subaqueous foraging among spinosaurids is undermined by selective bone sampling, inadequate statistical procedures, and use of inaccurate ecological categorizations.[71] The publication received positive comeback.[72]
The author of the 2022 publication has also aired an official paper in response.[73] The Earlier paper's publisher responsed as: '' We could really use some kind of comprehensive synthesis paper looking at all the lines of evidence and with clear definitions of terms and what exactly is being proposed. That should help clear things up.''[74]
Further adding to the Hone & Holtz, Mr. Handerson's argument; there is another study conducted by Nathan P. Myhrvold, Paul C. Sereno & co. that goes in depth to the theory and the sample analysis published by Nizar et. al. and explains The noticeable errors of using bone compactness and the pFDA for enunciating an entire lifestyle for a clade of Theropods, the Spinosaurids in general.[75]
Additional research comes with direct correlation with earlier researches findings about sampling and isotope inconsistencies as well as direct bias. [76][9]
The publication made by Stephanie Baumgart et. al. and her team.
They found out found that the attributed evidence isn't strong enough for Spinosaurus swimming submerged underwater. Spinosaurus more likely mostly hangs out on the shore.
Consistent with wading lifestyle. Their team wanted to add spinosaur specimens to the dataset, to see how a wider range of specimens impact the 2022 results. We focused on bone compactness (Cg) of a cross-sectional slice of bone, the ratio of bone area in the slice to the total area of the slice.
If they would have used the CT data, bone presence/absence is marked by how radiodense the bone material is. Black in a scan is low density material like air. White is the densest thing in the view, like the densest part of the bone. But lots of variation in density. The co-authors and I wanted to get a bone compactness (Cg) value of this Spinosaurus bone from CMN, so I sat down with the scan.[77]
The trouble was, the author wasn't sure where to set the overall threshold. They came up with 3 options, all of which looked reasonable, but had a huge range in Cg; and then, how much variation is there going to be within an individual? Within species? Between species?
They looked at Suchomimus and Spinosaurus leg bones and found quite the range. Which is most representative? Too much variation.[78] Ultimately, given amount of immense variation in the specimens and in data collection techniques, their team concluded that previously attributed evidence isn’t strong enough to put Spinosaurus swimming and diving entirely submerged. Spinosaurus still more than likely mostly hung out on shore.[76][79] Dave Hone et. al. additionally pointed out as; there are loads of little things that don't match up well with the idea of it swimming well (and some big ones) and lots of little things that better fit the wading hypothesis and this is one of them.[80]
- Additionally isotopes being rationed and researched; as earlier with the original isotope study; that they found out that it's a key thing that the pro-swimming side keep ignoring. While most of the signatures do point to croc / turtle etc. lifestyles, some have a fully terrestrial one that's inseparable from other regular genuses and species of theropods. So some specimens were literally spending months at a time on land (estimated tooth turn over of at least 60 days) with a terrestrial food source.[81][82][83]
Locomotion[]
Reconstructed skeleton with traditional, long-legged posture
A 2024 article co-authored by Sereno stated that the previous calculations by Sereno that were used to argue quadrupedality for Spinosaurus had erroneously shifted the center of mass in front of the hips.
Reconstructed foot, note straight claws and large hallux
They instead suggested that the dinosaur fit the criteria of being a graviportal (or slow-moving) biped. Thus rendering earlier quadrupedal or semi-quadruped theories ever more invalidated.[79][84]
Function of sail[]
It is uncertain of the function of this dinosaur's sail or hump, scientists have proposed several hypotheses including display, and heat regulation. The prominent feature the sail was could've made the animal seem even larger than it was, intimidating other animals.[85]
The structure may have been used for thermoregulation, if the structure contained abundant blood vessels, the animal could have used the sail's large surface area to absorb heat, but this would imply that the animal was only partly warm-blooded at best and lived in climates where night-time temperatures were cool or low and the sky usually not cloudy. It is also quite possible that it could've used it's sail 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 (Haldane's principle), face far greater problems of dissipating excess heat at higher temperatures, than gaining it at lower. The sails of large dinosaurs added considerably to the skin area of their bodies, but with very minimum increase of volume. In addition, if the sail was turned away from the sun, or positioned at about a 90-degree angle towards a cooling wind, the animal would quite effectively cool itself in the warm climate of Cretaceous Africa.[85]
Nevertheless, Bailey (1997) was of the opinion that a sail could have absorbed more heat than it would have radiated. And Bailey proposed instead that Spinosaurus and other dinosaurs with long neural spines had fatty humps on their backs for energy insulation, storage, and shielding from heat. It is possible that the sail of Spinosaurus was used for courtship, in a way similar to a peacock's tail. Stromer speculated that the size of the neural spines may have differed between males and females.[86]
Reconstructed skeleton in National Geographic Museum
Gimsa and colleagues (2015) proposed that the dorsal sail of Spinosaurus would be analogous to the dorsal fins of sailfish and served a hydrodynamic purpose. Gimsa and others pointed out that the more basal spinosaurids with longer legs round or crescent-shaped dorsal sails, whereas in Spinosaurus, the dorsal neural spines form a shape that was roughly rectangular, similar in shape to the dorsal fins of sailfish. They thus argue that Spinosaurus used its dorsal neural sail in the same manner as sailfish, and that it also employed its long, narrow tail to stun prey like a modern thresher shark. The sail might have possibly reduced yaw rotation by counteracting the lateral force in the direction opposite to the slash as suggested by Gimsa and colleagues (2015).[87]
However recent research has determined that the Sail of Spinosaurus creates quite a noticeable obstacle for Sumbmerged swimming and diving hypotheses proposed earlier. Firstly; David Hone and Thomas Holtz published a paper that they argue that the general body shape of Spinosaurus is poorly adapted for the attributed entirely submerged, aquatic lifestyle, drawing on the amount of water drag and aquatic instability from the sail, as well as the rigid trunk and seemingly scarcely-muscled tail. Animals like crocodilians require a flexible body in order to move through the water and make sharp turns when chasing prey, and this is directly contradicted by Hone and Holtz's findings.[49]
Shape of sail[]
The sail of Spinosaurus isn't complete in any specimen, they're all partial and incomplete. The new reconstructions of Spinosaurus by Ibraham in 2014 and 2020 reconstruct the sail as roughly square, with a light dip roughly in the middle of the sail. Because the sail of the FSAC-KK 11888 is not very well complete, with only one complete anterior neural spine, and the other 5 anterior spines being incomplete, and the posterior part of the FSAC-KK 11888 sail is unknown.[29] The sail could have been round or have a big notch in the back somewhere, which Scott Hartman made a speculative skeletal proposing this.
Paleoecology[]
Restoration of Spinosaurus with contemporaneous animals of the Bahariya Formation
The environment inhabited by Spinosaurus is only partially understood, and covers a great deal of what is now northern Africa. Those Spinosaurus that lived in what is now Egypt, for example, may have contended with shoreline conditions on tidal flats and channels, living in mangrove forests alongside similarly large dinosaurian predators Bahariasaurus and Carcharodontosaurus, giant titanosaur sauropod Paralititan, smaller titanosaur Aegyptosaurus, 10 meter (33 ft) long crocodilian Stomatosuchus, and the coelacanth Mawsonia.[88]
JPInstitute.com Description[]
The star of "Jurassic Park III," the Spinosaurus is one of the strangest of the large meat-eaters. What makes it so different is the large sail on its back, formed by spines that grew as tall as six feet. No one knows exactly why it had these on its back, but it is possible that they helped to regulate body temperature, or maybe they were used as a display during courtship. The other really interesting thing about this huge dinosaur was its diet - it seems to be designed to eat mostly fish!
The teeth of Spinosaurus are designed differently from any of the large carnivores. They are long and conical-shaped, the kind found on reptiles that eat mostly fish. How could something this large be so specially designed to eat mostly fish? It probably lived along the shore where fairly large fish were abundant. Of course, it could also have eaten just about anything else it could catch.
What is interesting is that there were two other dinosaurs living at the same time and in the same vicinity as Spinosaurus who also had large sails on their backs. What was it about this region that gave rise to this body type?
At one time, there was an almost complete specimen on display in a museum in Germany. However, it was completely destroyed and lost forever during the bombing of Germany in WWII.
Dinosaur Field Guide Description[]
Spinosaurus ("'spine lizard") is one of the most spectacular dinosaurs ever found. It was an enormous meat-eating dinosaur, as big as Tyrannosaurus rex. But its jaws and teeth were very different from T. rex's The jaws were long and slender, and the teeth were cone-shaped, like those of a crocodile. Its most distinctive feature, however, was the huge sail-like fin on its back. This sail was made from the spines that come out of the top of the backbones of dinosaurs and all other backboned animals. If you feel down your spine from the bottom of your head, you'll feel a series of bumps (especially at the base of the neck). These bumps are the same bumps on the top of backbones of dinosaurs. The spines of Spinosaurus, though, were tremendous: The longest one found was over 5 feet (1.7 m) tall! What would have been the purpose of such a sail? Although Spinosaurus lived in a swampy coastal environment, the sail would not have been used like the sail of a boat. Instead, it may have served to let Spinosaurus cool itself down if it got too hot. The skin on the sail, like all skin, would have been filled with blood vessels. Hot blood pumped into the sail would be cooled off, especially if there was a breeze; African elephants use blood vessels in their ears for this purpose. Also, the sail might have been used to show off to other Spinosaurus, either to attract a mate or to defend its territory. Additionally, the dinosaur may have used its sail to make itself look bigger. Living in the same environment as Spinosaurus were a couple of other giant predators, Carcharodontosaurus and Deltadromeus. If a Spinosaurus turned itself sideways toward an attacker, it would suddenly look much larger, and so the other predator might think twice about attacking. Modern cats do something similar: When they get scared, they puff up their fur to make themselves look larger.
Fun Facts[]
Old pictures of Spinosaurus showed it incorrectly with a Tyrannosaurus-like skull.
Trivia[]
Spinosaurus is not the only dinosaur with a sail. Ouranosaurus (a relative of Iguanodon) also had a sail. The sail-backed Dimetrodon of the Permian Period was not a dinosaur. It was, in fact, a primitive synapsid (or protomammai), more closely related to the ancestors of mammals.
Gallery[]
Appearance in other media[]
Jurassic Park[]
- Spinosaurus has become an iconic dinosaur and its fame started with the film, Jurassic Park III, the first Jurassic Park film not based on a Michael Crichton book. Spinosaurus was portrayed as the main "villain" that caused destruction in its path. In an infamous scene, this Spinosaurus was seen fighting a Tyrannosaurus rex and defeating it. A Spinosaurus fossil Skeleton was seen in Jurassic World where it was destroyed by the Tyrannosaurus, Rexy, during the Isla Nublar Incident of 2015. It is also one of the dinosaurs included in the Holoscape of Innovation Center, though it is unknown if Spinosaurus actually lives in Jurassic World. Spinosaurus also apparently into cruelty after the Isla Nublar Incident of 2015 before Jurassic World: Fallen Kingdom, on Isla Nublar, though it's unknown if there were any surviving populations left. However, it was planned to be in Jurassic World: Fallen Kingdom has a rematch with the T. rex before being cut from the film entirely. Spinosaurus also appears in most of the Jurassic Park expanded the universe, including games and toy lines.
- Spinosaurus appears in the game Jurassic World: Evolution. It is based on the Jurassic Park III variant.
- Spinosaurus does appear in the game Jurassic World: Alive with the same design as it does in Jurassic Park III.
- Spinosaurus appears in the game Jurassic World: The Game.
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Read more Spinosaurus on Jurassic Park Wiki |
The Land Before Time[]
- Spinosaurus also appears in the 12th episode of The Land Before Time television series but is inaccurately shown with only two fingers. It was also a minor antagonist in the Land Before Time XII: the Great Day of the Flyers.
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Read more Spinosaurus on Land Before Time Wiki |
Links[]
References[]
- ↑ 1.0 1.1 https://onlinelibrary.wiley.com/doi/abs/10.1111/1475-4983.00181
- ↑ https://journals.library.ualberta.ca/vamp/index.php/VAMP/article/view/29370
- ↑ https://www.nytimes.com/2021/01/26/science/spinosaurus-underwater-dinosaur.html
- ↑ https://www.livescience.com/spinosaurus-dinosaur-mediocre-swimmer.html
- ↑ https://www.seattletimes.com/nation-world/was-this-dinosaur-more-subaquatic-killer-or-giant-wading-bird/
- ↑ https://www.biorxiv.org/content/10.1101/2023.05.04.539484v1.full.pdf
- ↑ https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0298957
- ↑ https://sciencenews.strategian.com/public_html/2024/03/06/spinosaurus-didnt-swim-after-its-supper-study-claims/
- ↑ 9.0 9.1 https://archive.md/jS5Ww
- ↑ https://www.researchgate.net/publication/228733136_New_information_regarding_the_holotype_of_Spinosaurus_aegyptiacus_Stromer_1915
- ↑ https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.zobodat.at/pdf/Abhandlungen-Akademie-Bayern_NF_33_0001-0102.pdf&ved=2ahUKEwi25unX1OeEAxWkQfEDHfPRDG8QFnoECA0QAQ&usg=AOvVaw2s4_ICNFaeV7TZCo7LcSWM
- ↑ 12.0 12.1 12.2 Stromer, E. (1915). "Wirbeltier-Reste der baharije-Stufe (unterstes Cenoman).3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen. et nov. spec" (in German). Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften Mathematisch-physikalische Klasse Abhandlung 28: 1–32.
- ↑ Stromer, E. (1934). "Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltierreste der Baharîje-Stufe (unterstes Cenoman). 13. Dinosauria" (in German). Abhandlungen der Bayerischen Akademie der Wissenschaften Mathematisch-naturwissenschaftliche Abteilung, Neue Folge 22: 1–79.
- ↑ 14.0 14.1 Sereno, P.C.; Beck, A.L.; Dutheil, D.B.; Gado, B.; Larsson, H.C.E.; Lyon, G.H.; Marcot, J.D.; Rauhut, O.W.M.; Sadleir, R.W.; Sidor, C.A.; Varricchio, D.D.; Wilson, G.P; and Wilson, J.A. (1998). "A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids". Science 282: 1298–1302. doi:10.1126/science.282.5392.1298. PMID 9812890.
- ↑ 15.0 15.1 Russell, D.A. (1996). "Isolated dinosaur bones from the Middle Cretaceous of the Tafilalt, Morocco". Bulletin du Muséum National d'Histoire Naturelle, Paris, 4e série, section C 18' (2-3): 349–402.
- ↑ 16.0 16.1 16.2 16.3 16.4 16.5 Cite error: Invalid
<ref>tag; no text was provided for refs nameddalsassoetal05 - ↑ 17.0 17.1 Mortimer, M. (2004). "Megalosauroidea". The Theropod Database. University of Washington. http://web.archive.org/20090410083316/home.comcast.net/~eoraptor/Megalosauroidea.htm#Spinosaurusaegyptiacus. Retrieved on 2008-08-14.
- ↑ 18.0 18.1 18.2 Holtz, Jr., T.R., Molnar, R.E, and Currie, P.J. (2004). "Basal Tetanurae". The Dinosauria (second edition). University of California Press. pp. 71–110. ISBN 0-520-24209-2.
- ↑ 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
- ↑ Brusatte, S. and Sereno, P.C. (2007). "A new species of Carcharodontosaurus (Dinosauria: Theropoda) from the Cenomanian of Niger and its implications for allosauroid phylogeny." Journal of Vertebrate Paleontology, 25: 40A.
- ↑ Template:Cite book
- ↑ Dalla Vecchia (1995). "Second record of a site with dinosaur skeletal remains in Libya (northern Africa)." Natura Nascosta, 11: 16-21.
- ↑ https://petrifiedembryology.wordpress.com/petrified-embryology-volume-3-the-frozen-baby-dinosaurs-spinosaurus-dorsojuvencus/
- ↑ https://www.science.org/doi/abs/10.1126/science.1258750
- ↑ von Huene, F.R. (1926). "The carnivorous saurischia in the Jura and Cretaceous formations principally in Europe". Rev. Mus. La Plata 29: 35–167.
- ↑ 26.0 26.1 Glut, D.F. (1982). The New Dinosaur Dictionary. Secaucus, NJ: Citadel Press. pp. 226–228. ISBN 0-8065-0782-9.
- ↑ Paul, G.S. (1988). Predatory Dinosaurs of the World. New York: Simon and Schuster. 464 pp.
- ↑ Therrien, F.; and Henderson, D.M. (2007). "My theropod is bigger than yours...or not: estimating body size from skull length in theropods". Journal of Vertebrate Paleontology 27 (1): 108–115. doi:10.1671/0272-4634(2007)27[108:MTIBTY]2.0.CO;2.
- ↑ Mortimer, Mickey (2007-03-25). "Comments on Therrien and Henderson's new paper". Dinosaur Mailing List. http://dml.cmnh.org/2007Mar/msg00292.html. Retrieved on 2007-07-04.
- ↑ 30.0 30.1 Bailey, Jack Bowman (1997). "Neural spine elongation in dinosaurs: sailbacks or buffalo-backs?". Journal of Paleontology 71 (6): 1124–1146.
- ↑ 31.0 31.1 Halstead, L.B. (1975). The Evolution and Ecology of the Dinosaurs. London: Eurobook Limited. pp. 1–116. ISBN 0856540188.
- ↑ 32.0 32.1 Glut, Donald F. (2000). "Spinosaurus". Dinosaurs: The Encyclopedia. 1st Supplement. Jefferson, North Carolina: McFarland & Company, Inc.. pp. 329–333. ISBN 0-7864-0591-0.
- ↑ Charig, Alan J.; and Milner, Angela C. (1997). "Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey". Bulletin of the Natural History Museum, Geology Series 53 (1): 11–70.
- ↑ Rauhut, O.W.M. (2003). "The interrelationships and evolution of basal theropod dinosaurs". Special Papers in Palaeontology 69: 1–213.
- ↑ https://www.nature.com/articles/s41586-020-2190-3
- ↑ https://www.nationalgeographic.com/science/2020/04/spinosaurus-graphic-reconstructing-gigantic-aquatic-predator/
- ↑ https://www.nhm.ac.uk/discover/news/2022/march/spinosaurus-baryonyx-may-have-hunted-fish-underwater.html
- ↑ Subaqueous foraging among carnivorous dinosaurs | Nature
- ↑ Spinosaurus is not an aquatic dinosaur | eLife
- ↑ https://www.nhm.ac.uk/discover/how-did-baryonyx-change-what-we-knew-about-spinosaurs.html
- ↑ https://www.nature.com/articles/430033a
- ↑ https://paleorxiv.org/mjt95/
- ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734717/
- ↑ https://twitter.com/ivankay17/status/1354002825219624960
- ↑ https://www.nationalgeographic.com/science/phenomena/2014/09/11/the-new-spinosaurus/
- ↑ https://api.nationalgeographic.com/distribution/public/amp/science/2020/04/first-spinosaurus-tail-found-confirms-dinosaur-was-swimming
- ↑ https://blogs.scientificamerican.com/laelaps/spinosaurus-was-a-terrible-swimmer/
- ↑ https://royaltyrrellmuseum.wpcomstaging.com/2018/08/16/new-research-refutes-claims-that-spinosaurus-was-semi-aquatic/
- ↑ 49.0 49.1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6098948/
- ↑ https://api.nationalgeographic.com/distribution/public/amp/science/2020/04/spinosaurus-graphic-reconstructing-gigantic-aquatic-predator
- ↑ https://www.nature.com/articles/s41586-022-04528-0
- ↑ https://www.nationalgeographic.com/science/article/spinosaurus-had-penguin-like-bones-a-sign-of-hunting-underwater
- ↑ https://www.sciencenews.org/article/spinosaurus-bones-dinosaur-swim-paleontology
- ↑ https://phys.org/news/2022-03-dense-bones-spinosaurus-underwater.html
- ↑ https://pubs.geoscienceworld.org/gsa/geology/article-abstract/38/2/139/130188/Oxygen-isotope-evidence-for-semi-aquatic-habits?redirectedFrom=fulltext
- ↑ https://www.oieau.org/eaudoc/eaudoc/page/Oxygen-isotope-evidence-semi-aquatic-habits-among-spinosaurid-theropods-0
- ↑ https://www.researchgate.net/publication/222090629_Oxygen_isotope_evidence_for_semi-aquatic_habits_among_spinosaurid_theropods
- ↑ https://mobile.twitter.com/MarkWitton/status/1255814025931296769
- ↑ https://m.facebook.com/story.php?story_fbid=2539575042962116&id=100007289359441
- ↑ https://palaeo-electronica.org/content/2021/3219-the-ecology-of-spinosaurus
- ↑ https://archosaurmusings.wordpress.com/2021/01/26/the-evidence-for-spinosaurus-being-a-specialist-aquatic-predator-and-good-swimmer-is-weak/amp/?__twitter_impression=true
- ↑ https://twitter.com/Dave_Hone/status/1353959854835171334
- ↑ https://www.upi.com/Science_News/2021/01/26/Giant-dinosaur-hunted-from-the-shoreline-like-a-bird-not-an-aquatic-predator/4911611633287/
- ↑ https://www.nationalgeographic.com/science/article/did-the-river-monster-spinosaurus-hunt-like-a-stork
- ↑ https://edition.cnn.com/2021/01/26/world/spinosaurus-behavior-study-scli-intl-scn/index.html
- ↑ https://phys.org/news/2021-01-behaviour-giant-carnivorous-dinosaur-spinosaurus.html
- ↑ https://www.nationalgeographic.com/science/article/spinosaurus-had-penguin-like-bones-a-sign-of-hunting-underwater
- ↑ https://mobile.twitter.com/Dave_Hone/status/1506663165542686728
- ↑ https://mobile.twitter.com/Dave_Hone/status/1506875353125502977
- ↑ https://www.youtube.com/watch?v=TkBdxRkXbYM&t=2167s
- ↑ https://www.biorxiv.org/content/10.1101/2022.04.13.487781v1
- ↑ https://twitter.com/skeletaldrawing/status/1514777440626745363
- ↑ https://www.biorxiv.org/content/10.1101/2022.05.05.490811v1
- ↑ https://twitter.com/Dave_Hone/status/1523036298541293569
- ↑ https://www.biorxiv.org/content/biorxiv/early/2023/05/07/2023.05.04.539484.full.pdf
- ↑ 76.0 76.1 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0298957
- ↑ https://archive.md/jS5Ww
- ↑ https://twitter.com/Stephanopteryx/status/1765472382289080658
- ↑ 79.0 79.1 https://www.nytimes.com/2024/03/06/science/spinosaurus-dinosaur-fossil-dive.html
- ↑ https://twitter.com/Dave_Hone/status/1765479073260671329
- ↑ https://twitter.com/Dave_Hone/status/1765495775197335779
- ↑ https://twitter.com/Dave_Hone/status/1765495877202813359
- ↑ https://www.researchgate.net/publication/222090629_Oxygen_isotope_evidence_for_semi-aquatic_habits_among_spinosaurid_theropods
- ↑ https://archive.md/jS5Ww
- ↑ 85.0 85.1 https://www.jstor.org/stable/1306608
- ↑ Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen., nov. spec
- ↑ https://www.cambridge.org/core/journals/geological-magazine/article/riddle-of-spinosaurus-aegyptiacus-dorsal-sail/B19941405E1791A97230BCF003017B7B
- ↑ Smith, J.B.; Lamanna, M.C.; Lacovara, K.J.; Dodson, P.; Smith, J.R.; Poole, J.C.; Giegengack, R.; and Attia, Y. (2001). "A Giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt". Science 292 (5522): 1704–1706. doi:10.1126/science.1060561. PMID 11387472.