171-598: *disputed validity; = Spinosaurus ? Spinosauridae (or spinosaurids ) is a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera . Spinosaurid fossils have been recovered worldwide, including Africa , Europe , South America and Asia . Their remains have generally been attributed to the Early to Mid Cretaceous . Spinosaurids were large bipedal carnivores . Their crocodilian -like skulls were long, low and narrow, bearing conical teeth with reduced or absent serrations . The tips of their upper and lower jaws fanned out into
342-516: A baryonychine from Niger , on the basis of a partial skeleton found in 1997. In 2004, partial jaw bones were recovered from the Alcântara Formation , these were referred to a new genus of spinosaurine named Oxalaia in 2011 by Alexander Kellner . On 2021 a recent discovery in Isle of Wight an island off the south coast of England, remains of a spinosaurid which is said to be of a new species
513-573: A carcharodontosaurid similar to Acrocanthosaurus and a dentary from Baryonyx or Suchomimus . The analysis was rejected in at least one subsequent paper. NMC 50791, held by the Canadian Museum of Nature , is a mid-cervical vertebra which is 19.5 centimeters (7.7 in) long from the Kem Kem Beds of Morocco . It is the holotype of Spinosaurus maroccanus, as described by Russell in 1996. Other specimens referred to S. maroccanus in
684-508: A sail-like structure , although some authors have suggested that the spines were covered in fat and formed a hump. The hip bones of Spinosaurus were reduced, and the legs were very short in proportion to the body. Its long and narrow tail was deepened by tall, thin neural spines and elongated chevrons , forming a flexible fin or paddle-like structure. Spinosaurus is known to have eaten fish, and most scientists believe that it hunted both terrestrial and aquatic prey. Evidence suggests that it
855-455: A semiaquatic lifestyle for some members of this clade . This is further indicated by various anatomical adaptations, such as retracted eyes and nostrils; and the deepening of the tail in some taxa, which has been suggested to have aided in underwater propulsion akin to that of modern crocodilians . Spinosaurs are proposed to be closely related to the megalosaurid theropods of the Jurassic. This
1026-466: A 2007 paper using scaling based on skull length, challenged previous estimates of the size of Spinosaurus , finding the length too great and the weight too small. Based on estimated skull lengths of 1.5 to 1.75 m (4 ft 11 in to 5 ft 9 in), their estimates include a body length of 12.6 to 14.3 m (41 to 47 ft) and a body mass of 12 to 20.9 t (13.2 to 23.0 short tons). The lower estimates for Spinosaurus would imply that
1197-544: A 2020 study on variation within Spinosaurus considers these differences in morphology to be indicative of variation in skull morphology within a single species, as is the case in Allosaurus. Some scientists have considered the genus Sigilmassasaurus a junior synonym of Spinosaurus . In Ibrahim and colleagues (2014), the specimens of Sigilmassasaurus was referred to Spinosaurus aegyptiacus together with "Spinosaurus B" as
1368-660: A European origin for spinosaurids in 2021, with an expansion to Asia and Gondwana during the first half of the Early Cretaceous. In contrast to Sereno, these authors suggested there had been at least two dispersal events from Europe to Africa, leading to Suchomimus and the African part of Spinosaurinae. Spinosaurid teeth resemble those of crocodiles, which are used for piercing and holding prey. Therefore, teeth with small or no serrations, such as in spinosaurids, were not good for cutting or ripping into flesh but instead helped to ensure
1539-513: A condition not observed in MSNM V4047 which has been referred to as a specimen of Spinosaurus , and thus adding a new possible diagnostic feature of Oxalaia . They also suggested that the premaxilla of Oxalaia is wider in the posterior portion than that of MSNM V4047, and that the lateral morphology of its rostrum was distinguished from other spinosaurines based on their morphometric analysis. In 2023, Isasmendi and colleagues considered Oxalaia as
1710-467: A cooling wind, the animal would quite effectively cool itself in the warm climate of Cretaceous Africa. However, Bailey (1997) was of the opinion that a sail could have absorbed more heat than it radiated. Bailey proposed instead that Spinosaurus and other dinosaurs with long neural spines had fatty humps on their backs for energy storage, insulation, and shielding from heat. Many elaborate body structures of modern-day animals serve to attract members of
1881-498: A distinct genus, though a very close relative of Spinosaurus , the two unified in the tribe Spinosaurini, coined in the study. The 2020 study indicates synonymy between Spinosaurus and Sigilmassasaurus , and considered specimens previously referred to Sigilmassasaurus as those of Spinosaurus . For instance, the referral of an isolated quadrate (specimen MHNM.KK376) to Sigilmassasaurus brevicollis , based on its difference from other specimens assigned to Spinosaurus aegyptiacus ,
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#17328550501512052-468: A dorsal neural arch (SAM 128), belonged to S. maroccanus . Although it was originally ascribed to S. maroccanus , based on their examination of this cranial material, the 2016 study considered the difference between the two species to be not taxonomically significant and either ontogenetic or intraspecific, and thus tentatively assigned the specimen to S. aegyptiacus . The 2017 study considered MNHN SAM 124 to belong to same taxon as MSNM V4047. BM231 (in
2223-722: A great scheme for a National Museum of Natural History, which eventually resulted in the removal of the natural history collections of the British Museum to a new building at South Kensington : the British Museum (Natural History) (now the Natural History Museum ). He retained office until the completion of this work, in December 1883, when he was made a knight of the Order of the Bath . Owen always tended to support orthodox men of science and
2394-415: A greater reliance on its sense of smell and had a more piscivorous lifestyle than Irritator and baryonychines. Direct fossil evidence shows that spinosaurids fed on fish as well as a variety of other small to medium-sized animals, including dinosaurs. Baryonyx was found with scales of the prehistoric fish Scheenstia in its body cavity, and these were abraded, hypothetically by gastric juices. Bones of
2565-545: A heavy, pachyderm -like animal, as Owen was proposing, but had slender forelimbs. Owen was granted right of first refusal on any freshly dead animal at the London Zoo. His wife once arrived home to find the carcass of a newly deceased rhinoceros in her front hallway. At the same time, Sir Thomas Mitchell 's discovery of fossil bones, in New South Wales , provided material for the first of Owen's long series of papers on
2736-494: A high degree of similarity with those of other non-maniraptoriform theropods. Lengthwise atop their skulls ran a thin and shallow sagittal crest that was usually tallest near or above the eyes, either becoming shorter or disappearing entirely towards the front of the head. Spinosaurus 's head crest was comb-shaped and bore distinct vertical grooves, while those of Baryonyx and Suchomimus looked like small triangular bumps. Irritator ' s median crest stopped above and behind
2907-407: A hydrodynamic fulcrum and hydrodynamically stabilizing the trunk along the dorsoventral axis, Spinosaurus ’ sail would also have compensated for the inertia of the lateral neck by tail movements and vice versa not only for predation but also for accelerated swimming. This behavior might also have been one reason for Spinosaurus ’ muscular chest and neck reported by Ibrahim and colleagues (2014). It
3078-462: A malicious, dishonest and hateful individual. He has been described in one biography as being a "social experimenter with a penchant for sadism. Addicted to controversy and driven by arrogance and jealousy". Deborah Cadbury stated that Owen possessed an "almost fanatical egoism with a callous delight in savaging his critics." An Oxford University professor once described Owen as "a damned liar. He lied for God and for malice". Gideon Mantell claimed it
3249-486: A maximum body length of 14 m (46 ft) and a maximum body mass of 7.4 t (8.2 short tons) by constructing a CT-based 3D skeletal model "with the axial column in neutral pose." They argued that the 2D graphical reconstruction of the aquatic hypothesis by Ibrahim and his colleagues in 2020 overestimated the presacral column length by 10%, ribcage depth by 25%, and forelimb length by 30% over dimensions based on CT-scanned fossils; these proportional overestimates shift
3420-521: A monophyletic Megalosauroidea inside a more inclusive Carnosauria that is made up of both allosauroids and megalosauroids. The first spinosaurid fossil , a single conical tooth, was discovered circa 1820 by British paleontologist Gideon Mantell in the Wadhurst Clay Formation . In 1841 , naturalist Sir Richard Owen mistakenly assigned it to a crocodilian he named Suchosaurus (meaning "crocodile lizard"). A second species, S. girardi ,
3591-622: A new spinosaur was announced with the name of Riojavenatrix lacustris . Originally discovered in La Rioja in 2005, it is the 5th spinosaur species to be discovered in the Iberian Peninsula. It was found to have lived 120 million years ago and was around 7-8 metres long with a 1.5 metric ton body mass. Although reliable size and weight estimates for most known spinosaurids are hindered by the lack of good material, all known spinosaurids were large animals. The smallest genus known from good material
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#17328550501513762-467: A phylogenetic analysis incorporating a general range of theropods, but mostly focusing on Spinosauridae. The results of the analysis appear below: Megalosauridae [REDACTED] Baryonyx [REDACTED] "Spinosaurus B" MSNM V4047 FSAC-KK 11888 See also the phylogenetic results in the 2022 article describing Iberospinus . Spinosaurids appear to have been widespread from the Barremian to
3933-657: A relatively complete skeleton was excavated from the Smokejacks pit in Surrey , England . These remains were described by British paleontologists Alan J. Charig and Angela C. Milner in 1986 as the holotype of a new species, Baryonyx walkeri. After the discovery of Baryonyx, many new genera have since been described, with the majority from very incomplete remains. However, other finds bear enough fossil material and distinct anatomical features to be assigned with confidence. Paul Sereno and colleagues described Suchomimus in 1998 ,
4104-465: A secondary palate that made them more resistant to torsion. In contrast, the primitive and typical condition for theropods was a tall, narrow snout with blade-like (ziphodont) teeth with serrated carinae. The skull adaptations of spinosaurids converged with those of crocodilians ; early members of the latter group had skulls similar to typical theropods, later developing elongated snouts, conical teeth, and secondary palates. These adaptations may have been
4275-453: A shoal of fish or squid, sailfish also raise their sails to make themselves appear larger. When they slash or wipe their bills through shoaling fish by turning their heads, their dorsal sail and fins are outstretched to stabilize their bodies hydrodynamically (Lauder & Drucker, 2004). Domenici and colleagues (2014) postulate that these fin extensions enhance the accuracy of tapping and slashing. The sail can reduce yaw rotation by counteracting
4446-411: A significantly smaller pelvis (hip bone) than that of other giant theropods, with the surface area of the ilium (main body of the pelvis) half that of most members of the clade. The hind limbs were short, at just over 25 percent of the total body length, with the tibia (calf bone) being longer than the femur (thigh bone). Unlike in other theropods, the hallux (or fourth toe) of Spinosaurus touched
4617-401: A space on the inside of the snout, the authors speculated that Spinosaurus had pressure receptors inside the space that allowed it to hold its snout at the surface of the water to detect swimming prey species without seeing them. A 2013 study by Andrew R. Cuff and Emily J. Rayfield concluded that bio-mechanical data suggests that Spinosaurus was not an obligate piscivore and that its diet
4788-514: A specimen of Spinosaurus . As a spinosaurid, Spinosaurus would have had a long, muscular neck, curved in a sigmoid , or S-shape. Its shoulders were prominent, and the forelimbs large and stocky, bearing three clawed digits on each hand. The first finger (or "thumb") would have been the largest. Spinosaurus had long phalanges (finger bones), and only somewhat recurved claws , suggesting that its hands were longer compared to those of other spinosaurids. Very tall neural spines growing on
4959-444: A spoon-shaped structure similar to a rosette , behind which there was a notch in the upper jaw that the expanded tip of the lower jaw fit into. The nostrils of spinosaurids were retracted to a position further back on the head than in most other theropods, and they had bony crests on their heads along the midline of their skulls. Their robust shoulders wielded stocky forelimbs, with three-fingered hands that bore an enlarged claw on
5130-469: A statue of Darwin. A bust of Owen by Alfred Gilbert (1896) is held in the Hunterian Museum, London . A species of Central American lizard, Diploglossus owenii , was named in his honour by French herpetologists André Marie Constant Duméril and Gabriel Bibron in 1839. The Sir Richard Owen Wetherspoons pub in central Lancaster is named in his honour. Owen has been described by some as
5301-466: A strong grip on a struggling prey animal. Spinosaurid jaws were likened by Romain Vullo and colleagues to those of the pike conger eel , in what they hypothesized was convergent evolution for aquatic feeding. Both kinds of animals have some teeth in the end of the upper and lower jaws that are larger than the others and an area of the upper jaw with smaller teeth, creating a gap into which the enlarged teeth of
Spinosauridae - Misplaced Pages Continue
5472-580: A surgeon's apprentice in 1820 and was appointed to the Royal College of Surgeons in 1826. In 1836, Owen was appointed Hunterian professor at the Royal College, and in 1849, he succeeded William Clift as conservator of the Hunterian Museum . He held the latter office until 1856 when he became superintendent of the natural history department of the British Museum . He then devoted much of his energies to
5643-404: A trait commonly observed in animals which have a semi-aquatic feeding habit. Sir Richard Owen Sir Richard Owen KCB FRMS FRS (20 July 1804 – 18 December 1892) was an English biologist , comparative anatomist and palaeontologist . Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils . Owen produced
5814-489: A valid taxon based on the examination of its referred maxilla (MN 6119-V) which suggests that the position of its external naris would have been more anteriorly located, a condition similar to that of Irritator and baryonychines , differing from African spinosaurines including Spinosaurus aegyptiacus . Since its discovery, Spinosaurus has been a contender for the largest theropod dinosaur. Both Friedrich von Huene in 1926 and Donald F. Glut in 1982 listed it as among
5985-560: A vast array of scientific work, but is probably best remembered today for coining the word Dinosauria (meaning "Terrible Reptile " or "Fearfully Great Reptile"). An outspoken critic of Charles Darwin 's theory of evolution by natural selection , Owen agreed with Darwin that evolution occurred but thought it was more complex than outlined in Darwin's On the Origin of Species . Owen's approach to evolution can be considered to have anticipated
6156-456: A weight of 5 to 7 t (5.5 to 7.7 short tons; 4.9 to 6.9 long tons). The largest known genus is Spinosaurus , which was capable of reaching lengths of 14 m (46 ft) and weighed around 7.4 t (8.2 short tons; 7.3 long tons), making it the longest known theropod dinosaur and terrestrial predator . The closely allied Sigilmassasaurus may have grown to a similar or greater length, though its taxonomic relationship with Spinosaurus
6327-431: A wider distribution and supports the faunal exchange between South America and Africa during this time. However, subsequent studies have rejected the synonymy of Oxalaia with Spinosaurus aegyptiacus based on diagnostic features of the holotype (MN 6117-V) and the referred specimen (MN 6119-V). In 2021, Lacerda, Grillo and Romano noted that the anteromedial processes of the holotype maxillae (MN 6117-V) contact medially,
6498-411: A young Iguanodon , also abraded, were found alongside this specimen. If these represent Baryonyx ’s meal, the animal was, whether in this case a hunter, or a scavenger, an eater of more diverse fare than fish. Moreover, there is a documented example of a spinosaurid having eaten a pterosaur , as one Irritator tooth was found lodged within the fossil vertebrae of an ornithocheirid pterosaur found in
6669-425: Is Irritator , which was between 6 and 8 meters (20 and 26 feet) long and around 1 metric ton (1.1 short tons ; 0.98 long tons ) in weight. Ichthyovenator , Baryonyx , and Suchomimus ranged from 7.5 to 11 m (25 to 36 ft) long, and weighed between 1 and 5.2 t (1.1 and 5.7 short tons; 0.98 and 5.12 long tons). Oxalaia may have reached a length of between 12 and 14 m (39 and 46 ft) and
6840-585: Is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian stage of the Late Cretaceous period , about 100 to 94 million years ago . The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915 . The original remains were destroyed in World War II , but additional material came to light in
7011-480: Is a snout (consisting of partial premaxillae, partial maxillae, vomers , and a dentary fragment). Described by Taquet and Russell in 1998, the specimen is 13.4 to 13.6 centimeters (5.3–5.4 in) in width; no length was stated. The specimen was located in Algeria, and "is of Albian age." Taquet and Russell believed that the specimen, along with a premaxilla fragment (SAM 125), two cervical vertebrae (SAM 126–127), and
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7182-482: Is due to both groups sharing many features such an enlarged claw on their first manual ungual and an elongated skull. However, some propose that this group (which is known as the Megalosauroidea) is paraphyletic and that spinosaurs represent either the most basal tetanurans or as basal carnosaurs which are less derived than the megalosaurids. Some have proposed a combination of the two ideas with spinosaurs being in
7353-657: Is found. As per the findings, it is about 10 meters in length and weighed several tons. The prehistoric bones of the spinosaurid were found in a geological layer of rock known as the Vectis Formation in Compton Chine, it is the first identifiable theropod from the Vectis Formation. The study was led by Christopher Barker, a PhD doctoral student in vertebrate paleontology at the University of Southampton . In February 2024,
7524-569: Is marked by unserrated, straight teeth, and external nares which are further back on the skull than in baryonychines, and Baryonychinae, which contains the genera Baryonyx , Cristatusaurus , Suchosaurus , Suchomimus , Ceratosuchops , and Riparovenator, which is marked by serrated, slightly curved teeth, smaller size, and more teeth in the lower jaw behind the terminal rosette than in spinosaurines. Others, such as Siamosaurus , may belong to either Baryonychinae or Spinosaurinae, but are too incompletely known to be assigned with confidence. Siamosaurus
7695-526: Is possible similar relatives have not yet been discovered. In 2015, the German biophysicist Jan Gimsa and colleagues suggested that this feature could also have aided aquatic movement by improving manoeuvrability when submerged, and acted as fulcrum for powerful movements of the neck and tail (similar to those of sailfish or thresher sharks ). Spinosaurus Spinosaurus ( / ˌ s p aɪ n ə ˈ s ɔːr ə s / ; lit. ' spine lizard ' )
7866-552: Is stored in the Natural History Museum, London . FSAC-KK 11888 is a partial subadult skeleton recovered from the Kem Kem beds of North Africa. It was described by Ibrahim and colleagues in 2014 and designated as the neotype specimen, though Evers and colleagues rejected the neotype designation for FSAC-KK-11888 in 2015. It includes cervical vertebrae, dorsal vertebrae, neural spines, a complete sacrum, femora, tibiae, pedal phalanges, caudal vertebra, several dorsal ribs, and fragments of
8037-640: Is the longest known terrestrial predator from the fossil record, with an estimated length of up to 14 meters (46 ft) and body mass of up to 7.4 metric tons (8.2 short tons) (similar to the weight of an African elephant ). The closely related genus Sigilmassasaurus may have reached a similar or greater size, though its taxonomy is disputed. Direct fossil evidence and anatomical adaptations indicate that spinosaurids were at least partially piscivorous (fish-eating), with additional fossil finds indicating they also fed on other dinosaurs and pterosaurs . The osteology of spinosaurid teeth and bones has suggested
8208-581: Is the most extreme example and a fish specialist; Australian freshwater crocodiles , which have similarly shaped skulls to gharials, also specialize more on fish than sympatric, broad snouted crocodiles and are opportunistic feeders which eat all manner of small aquatic prey, including insects and crustaceans . Thus, spinosaurids' snouts correlate with piscivory; this is consistent with hypotheses of this diet for spinosaurids, in particular baryonychines, but it does not indicate that they were solely piscivorous. Further study by Andrew R. Cuff and Rayfield in 2013 on
8379-544: Is theorized to be probable that the Spinosaurus 's feet were webbed . The upward-projecting neural spines of spinosaurid vertebrae (backbones) were very tall, more so than in most theropods. In life, these spines would have been covered in skin or fat tissue and formed a sail down the animal's back, a condition that has also been observed in some carcharodontosaurid and ornithopod dinosaurs. The eponymous neural spines of Spinosaurus were extremely tall, measuring over 1 m (3 ft 3 in) in height on some of
8550-440: Is uncertain. This consistency in large body size among spinosaurids could have evolved as a byproduct of their preference for semiaquatic lifestyles, as without the need to compete with other large theropod dinosaurs for food, they would have been able to grow to massive lengths. Spinosaurid skulls —similar in many respects to those of crocodilians—were long, low and narrow. As in other theropods, various fenestrae (openings) in
8721-410: Is unclear whether Spinosaurus was primarily a terrestrial predator or a piscivore , as indicated by its elongated jaws, conical teeth and raised nostrils. The hypothesis of spinosaurs as specialized fish eaters has been suggested before by A. J. Charig and A. C. Milner for Baryonyx . They base this on the anatomical similarity with crocodilians and the presence of digestive acid-etched fish scales in
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#17328550501518892-518: The BA meeting, where William Flower performed the dissection). Visual evidence of the supposedly missing structures ( posterior cornu and hippocampus minor ) was used, in effect, to indict Owen for perjury: Owen had argued that the absence of those structures in apes was connected with the lesser size to which the ape brains grew, but he then conceded that a poorly developed version might be construed as present without preventing him from arguing that brain size
9063-519: The Cenomanian stages of the Cretaceous period , about 130 to 95 million years ago. Possibly the earliest remains of spinosaurids are known from the Middle Jurassic of Niger and India, the latter of which otherwise has no remains of spinosaurids. They shared features such as long, narrow, crocodile-like skulls; sub-circular teeth, with fine to no serrations; the terminal rosette of the snout; and
9234-521: The Great Exhibition of 1851 , but 33 were eventually produced when the Crystal Palace was relocated to Sydenham , in south London. Owen famously hosted a dinner for 21 prominent men of science inside the hollow concrete Iguanodon on New Year's Eve 1853. However, in 1849, a few years before his death in 1852, Gideon Mantell had realised that Iguanodon , of which he was the discoverer, was not
9405-507: The Kem Kem Group suggested the Brazilian spinosaurine Oxalaia to be a potential junior synonym of Spinosaurus aegyptiacus . This was based on looking at the specimens assigned to Oxalaia , and the supposed autapomorphies of this taxon to be insignificant and fall within the hypodigm of Spinosaurus aegyptiacus . If supported by future studies, this would imply Spinosaurus aegyptiacus had
9576-735: The Kem Kem beds in Morocco and Oxalaia from the Alcântara Formation in Brazil , though other researchers propose both genera to be distinct taxa . Spinosaurus is the longest known terrestrial carnivore ; other large carnivores comparable to Spinosaurus include theropods such as Tyrannosaurus , Giganotosaurus and Carcharodontosaurus . The most recent study suggests that previous body size estimates are overestimated, and that S. aegyptiacus reached 14 m (46 ft) in length and 7.4 t (8.2 short tons) in body mass. The skull of Spinosaurus
9747-505: The Museo di Storia Naturale di Milano ), described by Dal Sasso and colleagues in 2005 as Spinosaurus cf. S. aegyptiacus , consists of a snout (premaxillae, partial maxillae, and partial nasals) 98.8 centimeters (38.9 in) long from the Kem Kem Beds. An isolated fish vertebra, tentatively referred to Onchopristis , has been associated with the tooth alveolus of this specimen. Similarly,
9918-817: The Romualdo Formation of Brazil. This may represent a predation or a scavenging event. A fossil snout referred to Spinosaurus was discovered with a vertebra from the sclerorhynchid Onchopristis embedded in it. In the Sao Khua Formation of Thailand, isolated tooth crowns from Siamosaurus have been found in association with sauropod remains, indicating possible predation or scavenging. The Portuguese Iberospinus fossils were also found associated with isolated Iguanodon teeth, and those cases are listed; along with other such associations as support for opportunistic feeding behaviour in spinosaurids. A 2018 study by Auguste Hassler and colleagues of calcium isotopes in
10089-628: The Royal Botanic Gardens, Kew botanical collection (see Attacks on Hooker and Kew ), orchestrated by Acton Smee Ayrton : Owen's lost scientific standing was not due solely to his underhanded dealings with colleagues; it was also due to serious errors of scientific judgement that were discovered and publicized. A fine example was his decision to classify man in a separate subclass of the Mammalia (see Man's place in nature ). In this, Owen had no supporters at all. Also, his unwillingness to come off
10260-402: The Spinosaurus holotype specimen BSP 1912 VIII 19 discovered in the archives in 2000. On the basis of a photograph of the lower jaw and a photograph of the entire specimen as mounted, Smith concluded that Stromer's original 1915 drawings were slightly inaccurate. In 2003, Oliver Rauhut suggested that Stromer's Spinosaurus holotype was a chimera , composed of vertebrae and neural spines from
10431-643: The University of Chicago Paleontological Collection consists mainly of two narrow connected nasals with a fluted (ridged) crest from the region between the eyes. The specimen, which is 18.0 centimeters (7.1 in) long, was located in an early Cenomanian part of the Moroccan Kem Kem Beds in 1996 and described in the scientific literature in 2005 by Cristiano Dal Sasso of the Civic Natural History Museum in Milan and colleagues. MSNM V4047 (in
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#173285505015110602-414: The crown was often ornamented with longitudinal grooves or ridges. The coracoid bones of the shoulders in spinosaurids were robust and hook shaped. The arms were relatively large and well-built; the radius (long bone of the forearm) was stout and usually only half as long as the humerus (upper arm bone). Spinosaurid hands had three fingers, typical of tetanurans , and wielded an enlarged ungual on
10773-410: The dentaries (tooth bearing bones of the mandible) fit into, with a notch behind the expansion of the dentary. The maxillae (main upper jaw bones) were long and formed a low branch under the nostrils that connected to the rear of the premaxillae. The teeth at the frontmost part of the maxillae were small, becoming significantly larger soon after and then gradually decreasing in size towards the back of
10944-415: The dorsal (back) vertebrae. Suchomimus had a lower, ridge-like sail across the majority of its back, hip, and tail region. Baryonyx showed a reduced sail, with a few of the rearmost vertebral spines being somewhat elongated. Ichthyovenator had a sinusoidal (wave-like) sail that was separated in two over the hips, with the upper ends of some neural spines being broad and fan-shaped. A neural spine from
11115-409: The hallux (first toe) being reduced and elevated off the ground— Spinosaurus walked on four functional toes, with an enlarged hallux that came in contact with the ground. The unguals of its feet, in contrast with the deeper, smaller and recurved unguals of other theropods, were shallow, long, large in relation to the foot, and had flat bottoms. Based on comparisons with those of modern shorebirds , it
11286-421: The neotype and Spinosaurus maroccanus was considered as a nomen dubium following the conclusions of the other papers. A 2015 re-description of Sigilmassasaurus disputed these conclusions, and considered the genus valid, with inclusion of S. maroccanus as a synonym of Sigilmassasaurus instead. This conclusion was further supported in 2018 by Arden and colleagues, who consider Sigilmassasaurus to be
11457-779: The status quo . The royal family presented him with the cottage in Richmond Park and Robert Peel put him on the Civil List . In 1843, he was elected a foreign member of the Royal Swedish Academy of Sciences . In 1844 he became an associated member of the Royal Institute of the Netherlands. When this Institute became the Royal Netherlands Academy of Arts and Sciences in 1851, he joined as a foreign member. In 1845, he
11628-613: The supercontinent Pangea , but split with the opening of the Tethys Sea . Spinosaurines would then have evolved in the south (Africa and South America: in Gondwana ) and baryonychines in the north (Europe: in Laurasia ), with Suchomimus the result of a single north-to-south dispersal event . Buffetaut and the Tunisian palaeontologist Mohamed Ouaja also suggested in 2002 that baryonychines could be
11799-545: The Cenomanian age. Additionally, in 2024, a complete posterior cervical vertebra (specimen NHMUK PV R 38358) was assigned to Sigilmassasaurus brevicollis . Since the National Museum of Brazil fire in 2018 engulfed the palace housing the museum, with specimens of Oxalaia possibly being destroyed, any classification should remain tentative. In a 2020 paper written by Symth et al. in assessing spinosaurine specimens from
11970-439: The Cenomanian anywhere in the world. They attributed the disappearance of spinosaurids and other shifts in the fauna of Gondwana to changes in the environment, perhaps caused by transgressions in sea level . Malafaia and colleagues stated in 2020 that Baryonyx remains the oldest unquestionable spinosaurid, while acknowledging that older remains had also been tentatively assigned to the group. Barker and colleagues found support for
12141-609: The François Therrien and colleagues agreed that spinosaur forelimbs were probably used for hunting larger prey items, given that their snouts could not resist the bending stress. In a 2017 review of the family, David Hone and Holtz considered possible functions in digging for water sources or hard to reach prey, as well as burrowing into soil to construct nests. Theropod heads are often decorated with some form of crest, horn, or rugose structure, which in life, would have been extended by keratin. Though there has been little discussion on
12312-613: The Iberian region was a stepping stone between Europe and Africa, which is supported by the presence of baryonychines in Iberia. The direction of the dispersal between Europe and Africa is still unknown, and subsequent discoveries of spinosaurid remains in Asia and possibly Australia indicate that it may have been complex. In 2016, the Spanish palaeontologist Alejandro Serrano-Martínez and colleagues reported
12483-458: The Kem Kem region of southeastern Morocco, provided by François Escuillié and are deposited in the collections of the Muséum d’Histoire Naturelle of Marrakech. Only MHNM.KK376 is assigned to Sigilmassasaurus brevicollis , while the other five specimens are assigned to S. aegyptiacus , since the quadrates show two different morphologies, suggesting the existence of two spinosaurines in Morocco. However,
12654-647: The Nature of Limbs in 1849. At the end of On the Nature of Limbs , Owen suggested that humans ultimately evolved from fish as the result of natural laws, which resulted in Owen being criticized in the Manchester Spectator for denying that species such as humans were created by God. Owen, as president-elect of the British Association , announced his authoritative anatomical studies of primate brains, claiming that
12825-632: The Royal Society's Zoological Council for plagiarism . Another reason for his criticism of the Origin , some historians claim, was that Owen felt upstaged by Darwin and supporters such as Huxley, and his judgment was clouded by jealousy. Owen in Darwin's opinion was Owen also resorted to the same subterfuge he used against Mantell, writing another anonymous article in the Edinburgh Review in April 1860. In
12996-510: The Zoo began to publish scientific proceedings, in 1831, he was the most prolific contributor of anatomical papers. His first notable publication, however, was his Memoir on the Pearly Nautilus (London, 1832), which was soon recognized as a classic. Thenceforth, he continued to make important contributions to every department of comparative anatomy and zoology for a period of over fifty years. In
13167-411: The advantage of more expeditions and material, it appears that they pertain either to Carcharodontosaurus or to Sigilmassasaurus . S. maroccanus was originally described by Dale Russell in 1996 as a new species based on the length of its neck vertebrae. Specifically, Russell claimed that the ratio of the length of the centrum (body of vertebra) to the height of the posterior articular facet
13338-545: The ancestors of spinosaurines, which appear to have replaced the former in Africa. Milner suggested in 2003 that spinosaurids originated in Laurasia during the Jurassic, and dispersed via the Iberian land bridge into Gondwana, where they radiated . In 2007, Buffetaut pointed out that palaeogeographical studies had demonstrated that Iberia was near northern Africa during the Early Cretaceous, which he found to confirm Milner's idea that
13509-687: The animal was shorter and lighter than Carcharodontosaurus and Giganotosaurus . The Therrien and Henderson study has been criticized for the choice of theropods used for comparison (e.g., most of the theropods used to set the initial equations were tyrannosaurids and carnosaurs , which have a different build than spinosaurids), and for the assumption that the Spinosaurus skull could be as little as 1.5 m (4 ft 11 in) in length. In 2014, Ibrahim and his colleagues suggested that Spinosaurus aegyptiacus could reach over 15 m (49 ft) in length. In 2022, however, Paul Sereno and his colleagues suggested that Spinosaurus aegyptiacus reached
13680-448: The animal were found. Owen envisioned a resemblance of the animal to the living arthropod Limulus . Most of his work on reptiles related to the skeletons of extinct forms and his chief memoirs, on British specimens, were reprinted in a connected series in his History of British Fossil Reptiles (4 vols. London 1849–1884). He published the first important general account of the great group of Mesozoic land-reptiles, and he coined
13851-512: The animal; or for display purposes, such as intimidating rivals and predators, or attracting mates. Many elaborate body structures of modern-day animals serve to attract members of the opposite sex during mating. It is possible that the sail of Spinosaurus was used for courtship, in a way similar to a peacock 's tail. In 1915, Stromer speculated that the size of the neural spines may have differed between males and females. In 2012, French paleontologist Ronan Allain and colleagues suggested considering
14022-410: The article, Owen was critical of Darwin for not offering many new observations, and heaped praise (in the third person) upon himself, while being careful not to associate any particular comment with his own name. Owen did praise, however, the Origin 's description of Darwin's work on insect behaviour and pigeon breeding as "real gems". Owen was also a party to the threat to end government funding of
14193-438: The back vertebrae of Spinosaurus formed the basis of what is usually called the animal's " sail ". The lengths of the neural spines reached over 10 times the diameters of the centra (vertebral bodies) from which they extended. The neural spines were slightly longer front to back at the base than higher up, and were unlike the thin rods seen in the pelycosaur finbacks Edaphosaurus and Dimetrodon , contrasting also with
14364-452: The brains of all human races were really of similar size and intellectual ability, and that the fact that humans had brains that were twice the size of large apes like male gorillas, even though humans had much smaller bodies, made humans distinguishable. He was the first director in Natural History Museum in London and his statue was in the main hall there until 2009, when it was replaced with
14535-480: The center of mass anteriorly when translated to a flesh model, and thus the estimate from Ibrahim and his colleagues cannot be considered a reliable body size estimate. Its skull had a narrow snout filled with straight conical teeth that lacked serrations. There were six or seven teeth on each side of the very front of the upper jaw, in the premaxillae , and another twelve in both maxillae behind them. The second and third teeth on each side were noticeably larger than
14706-598: The classification that has long been accepted. Among Mollusca , he described not only the pearly nautilus but also Spirula (1850) and other Cephalopoda , both living and extinct, and it was he who proposed the universally-accepted subdivision of this class into the two orders of Dibranchiata and Tetrabranchiata (1832). In 1852 Owen named Protichnites – the oldest footprints found on land. Applying his knowledge of anatomy, he correctly postulated that these Cambrian trackways were made by an extinct type of arthropod , and he did this more than 150 years before any fossils of
14877-527: The collection of the Office National des Mines, Tunis) was described by Buffetaut and Ouaja in 2002. It consists of a partial anterior dentary 11.5 centimeters (4.5 in) in length from an early Albian stratum of the Chenini Formation of Tunisia . The dentary fragment, which included four alveoli and two partial teeth, was "extremely similar" to existing material of S. aegyptiacus . UCPC-2 in
15048-594: The complementary clade of all taxa closer to Baryonyx walkeri than to Spinosaurus aegyptiacus . Examinations by Marcos Sales, Cesar Schultz, and colleagues (2017) indicate that the South American spinosaurids Angaturama , Irritator , and Oxalaia were intermediate between Baronychinae and Spinosaurinae based on their craniodental features and cladistic analysis. This indicates that Baryonychinae may in fact be non-monophyletic. Their cladogram can be seen below. Baryonyx [REDACTED] The cladogram below depicts
15219-883: The condition observed in some other spinosaurids, though to a more extreme degree. Coupled with the also elongated chevron bones on the underside of the caudals, this resulted in a deep and narrow tail with a paddle or fin-like shape, comparable to the tails of newts and crocodilians . Spinosaurus gives its name to the dinosaur family Spinosauridae , which includes two subfamilies: Baryonychinae and Spinosaurinae. Baryonychinae includes Baryonyx from southern England and Suchomimus from Niger in central Africa . Spinosaurinae includes Spinosaurus , Siamosaurus , Ichthyovenator , Irritator , Angaturama (which may be synonymous with Irritator ), Sigilmassasaurus and Oxalaia (both of which may be synonymous with Spinosaurus ). The spinosaurines share unserrated straight teeth that are widely spaced (e.g., 12 on one side of
15390-473: The construction of the spinosaurid skull, and concluded that their mode of feeding was to use extremely quick, powerful strikes to seize small prey items using their jaws, whilst employing the powerful neck muscles in rapid up-and-down motion. Due to the narrow snout, vigorous side-to-side motion of the skull during prey capture is unlikely. Based on the size and positions of their nostrils, Marcos Sales and Cesar Schultz in 2017 suggested that Spinosaurus possessed
15561-527: The dentary fragment of Spinosaurus aegyptiacus , MPDM 31, is associated with the rostral tooth of Onchopristis . Like UCPC-2, it is thought to have come from the early Cenomanian. Arden and colleagues in 2018 tentatively assigned this specimen to Sigilmassasaurus brevicollis given its size. However, this assignment was later rejected by other researchers who considered the uniqueness of this specimen to be based on misinterpretations and poor preservation of another specimen, NHMUK R16665, another snout stored that
15732-790: The diet of spinosaurines from this environment may have included—in addition to pterosaurs—terrestrial and aquatic crocodyliforms , juveniles of their own species, turtles, and small to medium-sized dinosaurs. This would have made spinosaurines apex predators within this particular ecosystem. A 2024 study by D'Amore et al., further vindicates the theory that spinosaurids were similar in niche to generalist or macro-generalist crocodilians. This study likewise suggests their jaws and teeth were well-suited to quick strikes and deep, puncturing bites, but not for slicing flesh or crushing bones. In particular, baryonychine spinosaurids probably did little oral processing of their prey when feeding, but by comparison, spinosaurines were found to be quite capable of processing
15903-524: The discovery of the Iguanodon , completely excluding any credit for the original discoverer of the dinosaur, Gideon Mantell . This was not the first or last time Owen would falsely claim a discovery as his own. It has also been suggested by some authors that Owen even used his influence in the Royal Society to ensure that many of Mantell's research papers were never published. Owen was finally dismissed from
16074-761: The disputed Spinosaurus maroccanus (meaning "Moroccan spine lizard"). The first described remains of Spinosaurus were found and described in the early 20th century. In 1912, Richard Markgraf discovered a partial skeleton of a giant theropod dinosaur in the Bahariya Formation of western Egypt. In 1915, German paleontologist Ernst Stromer published an article assigning the specimen to a new genus and species, Spinosaurus aegyptiacus . Fragmentary additional remains from Bahariya, including vertebrae and hindlimb bones, were designated by Stromer as " Spinosaurus B " in 1934. Stromer considered them different enough to belong to another species, and this has been borne out. With
16245-422: The dorsal neural spines formed a shape that was roughly rectangular, similar in shape to the dorsal fins of sailfish. They therefore 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 . Sailfish employ their dorsal fins for herding schools of fish into a " bait ball " where they cooperate to trap
16416-436: The early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The type species is S. aegyptiacus from Egypt and Morocco . Although a potential second dubious species, S. maroccanus , has been recovered from Morocco, this dubious species is likely a junior synonym of S. aegyptiacus . Other possible junior synonyms include Sigilmassasaurus from
16587-458: The extinct mammals of Australia, which were eventually reprinted in book-form in 1877. He described Diprotodon (1838) and Thylacoleo (1859), and extinct species kangaroos and wombats of gigantic size. Most fossil material found in Australia and New Zealand was initially sent to England for expert examination, and with the assistance of the local collectors Owen became the first authority on
16758-402: The eyes in a bulbous, flattened shape. However, given that no fully preserved skulls are known for the genus, the complete shape of Irritator 's crest is unknown. Cristatusaurus and Suchomimus (a possible synonym of the former) both had narrow premaxillary crests. Angaturama (a possible synonym of Irritator ) had an unusually tall crest on its premaxillae that nearly overhung the tip of
16929-570: The fact that the median tubercle and median suture is present in BSPG 2011 I 115 but absent in FSAC-KK-18122, so the presence or absence of such feature should not be used to taxonomically separate isolated spinosaurid remains. Regardless of the synonymy of Sigilmassasaurus with Spinosaurus , some authors consider the possibility that there could be a second distinct spinosaurid in North Africa during
17100-486: The findings of Arden and colleagues (2018): Praia das Aguncheiras taxon Baryonyx walkeri [REDACTED] Eumeralla taxon Gara Samani taxon The function of the dinosaur's sail or hump is uncertain; scientists have proposed several hypotheses including heat regulation and display. In addition, such a prominent feature on its back could make it appear even larger than it was, intimidating other animals. The structure may have been used for thermoregulation . If
17271-406: The first digit . In many species , the upwards-projecting neural spines of the vertebrae (backbones) were significantly elongated and formed a sail on the animal's back (hence the family's etymology), which supported either a layer of skin or a fatty hump. The genus Spinosaurus , from which the family, one of its subfamilies (Spinosaurinae) and tribes (Spinosaurini) borrow their names,
17442-572: The first finger (or "thumb"), which formed the bony core of a keratin claw. In genera like Baryonyx and Suchomimus , the phalanges (finger bones) were of conventional length for large theropods, and bore hook-shaped, strongly curved hand claws. Based on fragmentary material from the forelimbs of Spinosaurus , it appears to have had longer, more gracile hands and straighter claws than other spinosaurids. The hindlimbs of Suchomimus and Baryonyx were somewhat short and mostly conventional of other megalosauroid theropods. Ichthyovenator 's hip region
17613-405: The fish into a certain area where the sailfish can snatch the fish with their bills. The sail could have possibly reduced yaw rotation by counteracting the lateral force in the direction opposite to the slash as suggested by Gimsa and colleagues (2015). Spinosaurus anatomy exhibits another feature that may have a modern analogy: its long tail resembled that of the thresher shark, employed to slap
17784-701: The former features are shared with their megalosaurid relatives. They also suggested that the spinosaurines and baryonychines diverged before the Barremian age of the Early Cretaceous. Several theories have been proposed about the biogeography of the spinosaurids. Since Suchomimus was more closely related to Baryonyx (from Europe) than to Spinosaurus —although that genus also lived in Africa—the distribution of spinosaurids cannot be explained as vicariance resulting from continental rifting . Sereno and colleagues proposed that spinosaurids were initially distributed across
17955-418: The former too. In 2022, Sakamoto estimated that Spinosaurus had an anterior bite force of 4,829 newtons and a posterior bite force of 11,936 newtons. Based on this estimate, he asserted that the jaws of Spinosaurus are adapted for generating relatively faster shutting speeds with less muscle input force, indicating that the animal likely killed its prey with fast-snapping jaws rather than slow-crushing bites,
18126-475: The generic level. Six main partial specimens of Spinosaurus have been described. BSP 1912 VIII 19, described by Stromer in 1915 from the Bahariya Formation, was the holotype . The material consisted of the following items, most of which were incomplete: right and left dentaries and splenials from the lower jaw measuring 75 centimeters (30 in) long; a straight piece of the left maxilla that
18297-426: The ground, and the phalanges of the toe bones were unusually long and well-built. At their ends were shallow claws that had flat bottoms. This type of foot morphology is also seen in shorebirds , indicating that Spinosaurus 's feet evolved for walking across unstable substrate and that they may have been webbed . From the caudal vertebrae of the tail projected significantly elongated, thin neural spines, akin to
18468-509: The head crests of spinosaurs, Hone and Holtz in 2017 considered that their most likely use was for displaying to potential mates or as a means of threatening rivals and other predators. Such has been suggested for theropod cranial structures before, which may have been aided by unusual or bright coloration to provide further visual cues. Many theories have been proposed over the years for the use of spinosaurid dorsal sails, such as thermoregulation ; to aid in swimming; to store energy or insulate
18639-539: The high diversity in neural spine elongation observed in theropod dinosaurs, as well as histological research done on the sails of synapsids (stem mammals), the sinusoidal sail of Ichthyovenator was likely used for courtship display or recognising members of its own species . In a 2013 blog post, Darren Naish considered the latter function unlikely, favouring the hypothesis of sexual selection for Ichthyovenator ' s sail because it appears to have evolved on its own, without very close relatives. Naish also notes it
18810-426: The holotype of Vallibonavenatrix shows a similar morphology to those of Ichthyovenator , indicating the presence of a sail in this genus as well. One partial skeleton possibly referable to Angaturama also had elongated neural spines on its hip region. The presence of a sail in fragmentary taxa like Sigilmassasaurus is unknown. In members of the subfamily Spinosaurinae, like Ichthyovenator and Spinosaurus ,
18981-509: The human brain had structures that ape brains did not and that therefore humans were a separate sub-class, starting a dispute which was subsequently satirised as the Great Hippocampus Question . Owen's main argument was that humans have much larger brains for their body size than other mammals including the great apes. In 1862 (and later occasions) Huxley took the opportunity to arrange demonstrations of ape brain anatomy (e.g. at
19152-483: The issues that have gained greater attention with the recent emergence of evolutionary developmental biology . Owen was the first president of the Microscopical Society of London in 1839 and edited many issues of its journal – then known as The Microscopic Journal . Owen also campaigned for the natural specimens in the British Museum to be given a new home. This resulted in the establishment, in 1881, of
19323-454: The jaw. Analysis of the teeth of spinosaurids and their comparison to the teeth of tyrannosaurids suggest that the deep roots of spinosaurids helped to better anchor the teeth of these animals and distribute the stress against lateral forces generated during bites in predation and feeding scenarios. Despite their highly modified skulls, analysis of the endocasts of Baryonyx walkeri and Ceratosuchops inferodios reveals spinosaurid brains shared
19494-617: The large claws, and subsequently probing for viscera with its long snout. In their 1997 article, Charig and Milner rejected this hypothesis, pointing out that in most cases, a carcass would have already been largely emptied out by its initial predators. Later research has also ruled out this sort of specialized scavenging. In 1986, Charig and Milner suggested that the robust forelimbs and giant thumb claws would have been Baryonyx 's primary method of capturing, killing, and tearing apart large prey; whereas its long snout would have been used mostly for fishing. A 2005 study by Canadian paleontologist
19665-404: The lateral force in the direction opposite to the slash. This means that prey is less likely to recognize the massive trunk as being part of an approaching predator (Marras and colleagues, 2015; Webb & Weihs 2015). Spinosaurus exhibited the anatomical features required to combine all three hunting strategies: a sail for herding prey more efficiently, as well as flexible tail and neck to slap
19836-513: The lower jaw fit, with the full structure called a terminal rosette. In the past, spinosaurids have often been considered piscivores (fish-eaters) in the main, based on comparisons of their jaws with those of modern crocodilians. In 2007, British paleontologist Emily J. Rayfield and colleagues conducted biomechanical studies on the skull of Baryonyx , which had a long, laterally compressed skull, comparing it to gharial (long, narrow, tubular) and alligator (flat and wide) skulls. They found that
20007-492: The maxilla), as opposed to the baryonychines, which have serrated curved teeth that are numerous (e.g., 30 on one side of the maxilla). An analysis of Spinosauridae by Arden and colleagues (2018) named the clade Spinosaurini and defined it as all spinosaurids closer to Spinosaurus aegyptiacus than to Irritator challengeri or Oxalaia quilombensis ; it also found Siamosaurus suteethorni and Icthyovenator laosensis to be members of Spinosaurinae. The subfamily Spinosaurinae
20178-403: The meat of relatively large vertebrate prey. None of these findings suggest any spinosaurids from either subfamily were restricted only to fish and small aquatic vertebrates. The use of the robust forelimbs and giant recurved claws of spinosaurs remains a debated topic. Charig and Milner speculated in 1986 that Baryonyx may have crouched by the riverbank and used its claws to gaff fish out of
20349-489: The most massive theropods in their surveys, at 15 m (49 ft) in length and upwards of 6 t (6.6 short tons) in weight. In 1988, Gregory S. Paul also listed it as the longest theropod at 15 m (49 ft), but gave a lower mass estimate of 4 t (4.4 short tons). In 2005, Dal Sasso and colleagues assumed that Spinosaurus and the related Suchomimus had the same body proportions in relation to their skull lengths, and thereby calculated that Spinosaurus
20520-550: The name Dinosauria from Greek δεινός ( deinos ) "terrible, powerful, wondrous" + σαύρος ( sauros ) "lizard". Owen used 3 genera to define the dinosaurs: the carnivorous Megalosaurus , the herbivorous Iguanodon and armoured Hylaeosaurus ' , specimens uncovered in southern England. With Benjamin Waterhouse Hawkins , Owen helped create the first life-size sculptures depicting dinosaurs as he thought they might have appeared. Some models were initially created for
20691-409: The neural spines of the caudal (tail) vertebrae were tall and reclined, accompanied by also elongated chevrons —long, thin bones that form the underside of the tail. This was most pronounced in Spinosaurus , in which the spines and chevrons formed a large paddle-like structure, deepening the tail significantly along most of its length. The family Spinosauridae was named by Stromer in 1915 to include
20862-399: The new term Spinosaurini for the clade of Sigilmassasaurus and Spinosaurus . Baryonyx walkeri [REDACTED] Eumeralla taxon Gara Samani taxon In 2021, Chris Barker, Hone, Darren Naish , Andrea Cau , Lockwood, Foster, Clarkin, Schneider, and Gostling described two new spinosaurid species, Ceratosuchops inferodios and Riparovenator milnerae . In the paper, they performed
21033-522: The newly discovered Baryonyx , before it was referred to Spinosauridae. Their subfamily was defined by Holtz and colleagues in 2004, as the complementary clade of all taxa closer to Baryonyx walkeri than to Spinosaurus aegyptiacus . Examinations in 2017 by Marcos Sales and Cesar Schultz indicate that the South American spinosaurids Angaturama and Irritator were intermediate between Baronychinae and Spinosaurinae based on their craniodental features and cladistic analysis. A study by Arden et al. 2018 named
21204-619: The now world-famous Natural History Museum in South Kensington , London. Bill Bryson argues that, "by making the Natural History Museum an institution for everyone, Owen transformed our expectations of what museums are for." While he made several contributions to science and public learning, Owen was a controversial figure among his contemporaries, both for his disagreements on matters of common descent and for accusations that he took credit for other people's work. Owen became
21375-658: The oldest known spinosaurid fossil, a tooth from the Middle Jurassic of Niger, which they found to suggest that spinosaurids originated in Gondwana, since other known Jurassic spinosaurid teeth are also from Africa, but they found the subsequent dispersal routes unclear. Some later studies instead suggested this tooth belonged to a megalosaurid . Candeiro and colleagues suggested in 2017 that spinosaurids of northern Gondwana were replaced by other predators, such as abelisauroids , since no definite spinosaurid fossils are known from after
21546-548: The opposite sex during mating. 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. Gimsa and colleagues (2015) suggest that the dorsal sail of Spinosaurus was analogous to the dorsal fins of sailfish and served a hydrodynamic purpose. Gimsa and others point out that more basal, long-legged spinosaurids had otherwise round or crescent-shaped dorsal sails, whereas in Spinosaurus ,
21717-616: The palaeontology of the region. While occupied with so much material from abroad, Owen was also busily collecting facts for an exhaustive work on similar fossils from the British Isles and, in 1844–1846, he published his History of British Fossil Mammals and Birds , which was followed by many later memoirs, notably his Monograph of the Fossil Mammalia of the Mesozoic Formations (Palaeont. Soc., 1871). One of his latest publications
21888-548: The postorbital part of the skull of MSNM V4047 had a shape similar to the postorbital part of the skull of Irritator , Dal Sasso and colleagues (2005) estimated that the skull of Spinosaurus was 1.75 meters (5.7 ft) long, but more recent estimates suggest a length of 1.6–1.68 meters (5.2–5.5 ft). The Dal Sasso and colleagues skull length estimate is questioned because skull shapes can vary across spinosaurid species and because MSNM V4047 may not belong to Spinosaurus itself, though recent studies have reconfirmed it as
22059-423: 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 large dinosaurs added considerably to the skin area of their bodies, with minimum increase of volume. Furthermore, if the sail was turned away from the sun, or positioned at a 90 degree angle towards
22230-403: The rest of the teeth in the premaxilla, creating a space between them and the large teeth in the front of the maxilla; large teeth in the lower jaw faced this space. The very tip of the snout holding those few large front teeth was expanded, and a small crest was present in front of the eyes. Using the dimensions of three specimens known as MSNM V4047, UCPC-2, and BSP 1912 VIII 19, and assuming that
22401-400: The result of a dietary change from terrestrial prey to fish. Unlike crocodiles, the post-cranial skeletons of baryonychine spinosaurids do not appear to have aquatic adaptations. Sereno and colleagues proposed in 1998 that the large thumb-claw and robust forelimbs of spinosaurids evolved in the Middle Jurassic, before the elongation of the skull and other adaptations related to fish-eating, since
22572-468: The results from the modeling were not scaled according to size, then both spinosaurids performed better than all the crocodilians in resistance to bending and torsion, due to their larger size. Thus, Cuff and Rayfield suggested that the skulls were not efficiently built to deal well with relatively large, struggling prey, but that spinosaurids may overcome prey simply by their size advantage, and not skull build. In 2002, Hans-Dieter Sues and colleagues studied
22743-553: The rib cage of the type specimen . Large fish are known from the faunas containing other spinosaurids, including the Mawsonia , in the mid-Cretaceous of northern Africa and Brazil. Direct evidence for spinosaur diet comes from related European and South American taxa. Baryonyx was found with fish scales and bones from juvenile Iguanodon in its stomach, while a tooth embedded in a South American pterosaur bone suggests that spinosaurs occasionally preyed on pterosaurs, but Spinosaurus
22914-485: The roof of their mouths that are also found in extant crocodilians, but not in most theropod dinosaurs. Oxalaia had a particularly elaborate secondary palate, while most spinosaurs had smoother ones. The teeth of spinosaurids were conical, with an oval to circular cross section and either absent or very fine serrations . Their teeth ranged from slightly recurved, such as those of Baryonyx and Suchomimus , to straight, such as those of Spinosaurus and Siamosaurus , and
23085-604: The sail of the Permian synapsid Dimetrodon , which lived before the dinosaurs even appeared, produced by convergent evolution . The structure may also have been more hump-like than sail-like, as noted by Stromer in 1915 ("one might rather think of the existence of a large hump of fat [ German : Fettbuckel ], to which the [neural spines] gave internal support") and by Jack Bowman Bailey in 1997. In support of his "buffalo-back" hypothesis, Bailey argued that in Spinosaurus , Ouranosaurus , and other dinosaurs with long neural spines,
23256-539: The same paper were two other mid-cervical vertebrae (NMC 41768 and NMC 50790), an anterior dentary fragment (NMC 50832), a mid-dentary fragment (NMC 50833), and an anterior dorsal neural arch (NMC 50813). Russell stated that "only general locality information could be provided" for the specimen, and therefore it could be dated only "possibly" to the Albian. MNHN SAM 124, housed at the Muséum National d'Histoire Naturelle ,
23427-459: The single genus Spinosaurus . The clade was expanded as more close relatives of Spinosaurus were uncovered. The first cladistic definition of Spinosauridae was provided by Paul Sereno in 1998 (as "All spinosauroids closer to Spinosaurus than to Torvosaurus "). Traditionally, Spinosauridae is divided into two subfamilies: Spinosaurinae, which contains the genera Icthyovenator , Irritator , Oxalaia , Sigilmassasaurus and Spinosaurus ,
23598-424: The skull aided in reducing its weight. In spinosaurs however, the antorbital fenestrae were greatly reduced, akin to those of crocodilians. The tips of the premaxillae (frontmost snout bones) were expanded in a spoon shape, forming what has been called a "terminal rosette " of enlarged teeth. Behind this expansion, the upper jaw had a notch bearing significantly smaller teeth, into which the also expanded tips of
23769-690: The skull. The body proportions of the specimen have been debated, as the hind limbs are disproportionately shorter in the specimen than in previous reconstructions. However, it has been demonstrated by multiple paleontologists that the specimen is not a chimera, and is indeed a specimen of Spinosaurus that suggests that the animal had much smaller hind limbs than previously thought. Other known specimens consist mainly of very fragmentary remains and scattered teeth. These include: MHNM.KK374, MHNM.KK375, MHNM.KK376, MHNM.KK377, MHNM.KK378 and MSNM V6896 are six isolated quadrates (skull bones) of different sizes that were collected by locals and acquired commercially in
23940-475: The skulls of Spinosaurus and Baryonyx did not recover similarities in the skulls of Baryonyx and the gharial that the previous study did. Baryonyx had, in models where the size difference of the skulls was corrected for, greater resistance to torsion and dorsoventral bending than both Spinosaurus and the gharial, while both spinosaurids were inferior to the gharial, alligator, and slender-snouted crocodile in resisting torsion and medio-lateral bending. When
24111-607: The snout with a small forward protrusion. Spinosaurid nostrils were set far back on the skull, at least behind the teeth of the premaxillae, instead of at the front of the snout as in most theropods. Those of Baryonyx and Suchomimus were large and started between the first and fourth maxillary teeth, while Spinosaurus 's nostrils were far smaller and more retracted. Irritator 's nostrils were positioned similarly to those of Baryonyx and Suchomimus , and were between those of Spinosaurus and Suchomimus in size. Spinosaurids had long secondary palates , bony and rugose structures on
24282-508: The species as valid without much comment, most researchers regard S. maroccanus as a nomen dubium (dubious name) or as a junior synonym of S. aegyptiacus . Some studies have referred the holotype and other referred specimens of S. maroccanus (NMC 50791 and MNHN SAM 124-128) as S. cf. aegyptiacus . The specimens previously ascribed as paratypes of S. maroccanus (NMC 41768 and NMC 50790) are reidentified as indeterminate spinosaurid specimens that are currently not identifiable at
24453-484: The spines were relatively shorter and thicker than the spines of pelycosaurs (which are known to have sails); instead, the dinosaurs' neural spines were similar to the neural spines of extinct hump-backed mammals such as Megacerops and Bison latifrons . In 2014, Ibrahim and colleagues instead posited that the spines were covered tightly by skin, similar to a crested chameleon , given their compactness, sharp edges, and likely poor blood flow . Spinosaurus had
24624-414: The sponges, Owen was the first to describe the now well-known Venus' Flower Basket or Euplectella (1841, 1857). Among Entozoa, his most noteworthy discovery was that of Trichina spiralis (1835), the parasite infesting the muscles of man in the disease now termed trichinosis (see also, however, Sir James Paget ). Of Brachiopoda he made very special studies, which much advanced knowledge and settled
24795-426: The structure 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 night-time temperatures were cool or low and the sky usually not cloudy. It is also possible that the structure was used to radiate excess heat from the body, rather than to collect it. Large animals, due to
24966-411: The structure of baryonychine jaws converged on that of gharials, in that the two taxa showed similar response patterns to stress from simulated feeding loads, and did so with and without the presence of a (simulated) secondary palate. The gharial, exemplar of a long, narrow, and tubular snout, is a fish specialist. However, this snout anatomy does not preclude other options for the spinosaurids. The gharial
25137-460: The teeth of North African theropods found that spinosaurids had a mixed diet of fish and herbivorous dinosaurs, whereas the other theropods examined ( abelisaurids and carcharodontosaurids ) mainly fed on herbivorous dinosaurs. This might indicate ecological partitioning between these theropods. Later in 2018, Tito Aureliano and colleagues presented a possible scenario for the food web of Brazilian Romualdo Formation. The researchers proposed that
25308-475: The thicker spines in the iguanodontian Ouranosaurus . Spinosaurus sails were unusual, although other dinosaurs, namely Ouranosaurus , which lived a few million years earlier in the same general region as Spinosaurus , and the Early Cretaceous South American sauropod Amargasaurus , might have developed similar structural adaptations of their vertebrae. The sail may be an analog of
25479-819: The tribe Spinosaurini to include Spinosaurus and Sigilmassasaurus , the latter of which's validity as a spinosaurid is debated. In 2021 Barker et al. named the new tribe Ceratosuchopsini within the Baryonychinae to encompass Suchomimus , Riparovenator , and Ceratosuchops . The 2017 study mentioned above indicates that Baryonychinae may in fact be non-monophyletic. Their cladogram can be seen below. Baryonyx [REDACTED] The next cladogram displays an analysis of Tetanurae simplified to show only Spinosauridae from Allain colleagues in 2012: Baryonyx [REDACTED] The 2018 phylogenetic analysis by Arden and colleagues, which included many unnamed taxa, resolved Baryonychinae as monophyletic, and also coined
25650-415: The unusually long neural spines not seen previously in any other theropod. In April 1944, the holotype of S. aegyptiacus was destroyed during an allied bombing raid in World War II . In 1934, Stromer referred a partial skeleton also from the Bahariya Formation to a new species of Spinosaurus; the specimen has since been alternatively assigned to another African spinosaurid, Sigilmassasaurus . In 1983,
25821-539: The water for stunning, injuring or killing prey. The submerged dorsal sail would have provided a strong centreboard-like counterforce for powerful sidewards movements of the strong neck and long tail, as performed by sailfish (Domenici and colleagues, 2014) or thresher sharks (Oliver and colleagues, 2013). While smaller dorsal sails or fins make the dorsal water volume better accessible for slashing, it can be speculated that their smaller stabilization effect makes lateral slashing less efficient (e.g. for thresher sharks). Forming
25992-451: The water to herd and stun shoals of fish before devouring them (Oliver and colleagues, 2013). The strategies that sailfish and thresher sharks employ against shoaling fish are more effective when the shoal is first concentrated into a ‘bait ball’ (Helfman, Collette & Facey, 1997; Oliver and colleagues, 2013; Domenici and colleagues, 2014). Since this is difficult for individual predators to achieve, they cooperate in this effort. When herding
26163-415: The water, similarly to grizzly bears . In 1987, British biologist Andrew Kitchener argued that with both its crocodile-like snout and enlarged claws, Baryonyx seemed to have too many adaptations for piscivory when one would have been enough. Kitchener instead postulated that Baryonyx more likely used its arms to scavenge the corpses of large dinosaurs, such as Iguanodon , by breaking into the carcass with
26334-643: Was semiaquatic ; how capable it was of swimming has been strongly contested. Spinosaurus 's leg bones had osteosclerosis (high bone density), allowing for better buoyancy control. Multiple functions have been put forward for the dorsal sail, including thermoregulation and display ; either to intimidate rivals or attract mates. It lived in a humid environment of tidal flats and mangrove forests alongside many other dinosaurs, as well as fish, crocodylomorphs , lizards, turtles, pterosaurs , and plesiosaurs . Two species of Spinosaurus have been named: Spinosaurus aegyptiacus (meaning "Egyptian spine lizard") and
26505-402: Was "a pity a man so talented should be so dastardly and envious". Richard Broke Freeman described him as "the most distinguished vertebrate zoologist and palaeontologist ... but a most deceitful and odious man". Charles Darwin stated that "No one fact tells so strongly against Owen ... as that he has never reared one pupil or follower." Owen famously credited himself and Georges Cuvier with
26676-431: Was 1.1 in S. aegyptiacus and 1.5 in S. maroccanus . Later authors have been split on this topic. Some authors note that the length of the vertebrae can vary from individual to individual, that the holotype specimen was destroyed and thus cannot be compared directly with the S. maroccanus specimen, and that it is unknown which cervical vertebrae the S. maroccanus specimens represent. Therefore, though some have retained
26847-533: Was 16 to 18 m (52 to 59 ft) in length and 7 to 9 t (7.7 to 9.9 short tons) in weight. The estimates were criticized because the skull length estimate was uncertain, and (assuming that body mass increases as the cube of body length) scaling Suchomimus, which was 11 m (36 ft) long and 3.8 t (4.2 short tons) in mass, to the range of estimated lengths of Spinosaurus would produce an estimated body mass of 11.7 to 16.7 t (12.9 to 18.4 short tons). François Therrien and Donald Henderson, in
27018-630: Was a little work entitled Antiquity of Man as deduced from the Discovery of a Human Skeleton during Excavations of the Docks at Tilbury (London, 1884). Sometime during the 1840s Owen came to the conclusion that species arise as the result of some sort of evolutionary process. He believed that there were a total of six possible mechanisms: Parthenogenesis , prolonged development, premature birth, congenital malformations, Lamarckian atrophy , Lamarckian hypertrophy and transmutation, of which he thought transmutation
27189-427: Was classified as a spinosaurine in 2018, but the results are provisional and not entirely conclusive. The subfamily Spinosaurinae was named by Sereno in 1998, and defined by Thomas Holtz and colleagues in 2004 as all taxa closer to Spinosaurus aegyptiacus than to Baryonyx walkeri . The subfamily Baryonychinae was named by Charig & Milner in 1986. They erected both the subfamily and the family Baryonychidae for
27360-410: Was described but not drawn; 20 teeth; 2 cervical vertebrae; 7 dorsal (trunk) vertebrae; 3 sacral vertebrae; 1 caudal vertebra; 4 thoracic ribs; and gastralia . Of the nine neural spines whose heights are given, the longest ("i," associated with a dorsal vertebra) was 1.65 meters (5.4 ft) in length. Stromer claimed that the specimen was from the early Cenomanian, about 97 million years ago. It
27531-621: Was destroyed in World War II , specifically "during the night of 24/25 April 1944 in a British bombing raid of Munich" that severely damaged the building housing the Paläontologisches Museum München (Bavarian State Collection of Paleontology). However, detailed drawings and descriptions of the specimen remain. Stromer's son donated Stromer's archives to the Paläontologische Staatssammlung München in 1995, and Smith and colleagues analyzed two photographs of
27702-646: Was elected as a member to the American Philosophical Society. He died at home on 15 December 1892 and is buried in the churchyard at St Andrew's Church , Ham , near Richmond, Surrey . While occupied with the cataloguing of the Hunterian collection, Owen did not confine his attention to the preparations before him but also seized every opportunity to dissect fresh subjects. He was allowed to examine all animals that died in London Zoo 's gardens and, when
27873-594: Was later named in 1897 . However, the spinosaurid nature of Suchosaurus was not recognized until a 1998 redescription of Baryonyx . The first fossils referred to a spinosaurid were discovered in 1912 at the Bahariya Formation in Egypt. Consisting of vertebrae , skull fragments, and teeth, these remains became the holotype specimen of the new genus and species Spinosaurus aegyptiacus in 1915 , when they were described by German paleontologist Ernst Stromer . The dinosaur's name meant "Egyptian spine lizard", in reference to
28044-408: Was likely to have been a generalized and opportunistic predator, possibly a Cretaceous equivalent of large grizzly bears , being biased toward fishing, though it undoubtedly scavenged and took many kinds of small or medium-sized prey. In 2009, Dal Sasso and colleagues. reported the results of X-ray computed tomography of the MSNM V4047 snout. As the foramina on the outside all communicated with
28215-457: Was long, low, and narrow, similar to that of a modern crocodilian , and bore straight conical teeth with no serrations . It would have had large, robust forelimbs bearing three-fingered hands, with an enlarged claw on the first digit . The distinctive neural spines of Spinosaurus , which were long extensions of the vertebrae (or backbones), grew to at least 1.65 m (5.4 ft) long and were likely to have had skin connecting them, forming
28386-451: 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 ( Baryonyx ) and modern alligators. This suggests that Spinosaurus preyed more regularly on fish than it did on land animals, although considered predators of
28557-428: Was named by Sereno in 1998, and defined by Holtz and colleagues (2004) as all taxa closer to Spinosaurus aegyptiacus than to Baryonyx walkeri . The subfamily Baryonychinae was named by Charig & Milner in 1986. They erected both the subfamily and the family Baryonychidae for the newly discovered Baryonyx , before it was referred to Spinosauridae. Their subfamily was defined by Holtz and colleagues in 2004, as
28728-461: Was reduced, having the shortest pubis (pubic bone) and ischium (lower and rearmost hip bone) in proportion to the ilium (main hip bone) of any other known theropod. Spinosaurus had an even smaller pelvis and hindlimbs in proportion to its body size; its legs composed just over 25 percent of the total body length. Substantially complete spinosaurid foot remains are only known from Spinosaurus . Unlike most theropods—which walk on three toes, with
28899-410: Was rejected by the 2020 study which noted that these differences in morphology are indicative of variation in skull morphology within a single species. The 2019 study assigned a juvenile specimen FSAC-KK-18122 to Sigilmassasaurus brevicollis based on its identical proportion to BSPG 2011 I 115 which was assigned to the taxon in a 2015 study, but this referral was also rejected in a 2020 study based on
29070-581: Was still the major way of distinguishing apes and humans. Huxley's campaign ran over two years and was devastatingly successful at persuading the overall scientific community, with each "slaying" being followed by a recruiting drive for the Darwinian cause. The spite lingered. While Owen had argued that humans were distinct from apes by virtue of having large brains, Huxley claimed that racial diversity blurred any such distinction. In his paper criticizing Owen, Huxley directly states: Owen countered Huxley by saying
29241-564: Was the least likely. Science historian Evelleen Richards has argued that Owen was likely sympathetic to developmental theories of evolution, but backed away from publicly proclaiming them after the critical reaction that had greeted the anonymously published evolutionary book Vestiges of the Natural History of Creation in 1844 (it was revealed only decades later that the book had been authored by publisher Robert Chambers ). Owen had been criticized for his own evolutionary remarks in his On
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