How large was the sinosauropteryx?
Sinosauropteryx
"Sinosauropteryx" was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of .
Chinshakiangosaurus
Like all sauropods, it was a large, quadrupedal herbivore with long neck and tail. The body length of the only specimen is estimated at 12 to 13 meters. The remains consists of the dentary (the tooth bearing bone of the mandible) including teeth as well as several parts of the postcranium. By now, only the dentary and the teeth were studied extensively; the remaining skeleton still awaits a proper description.
Sinosaurus
Shaojin Hu (1993) assigned specimen KMV 8701 to "Dilophosaurus sinensis". In 2013, a study by Currie et al., confirmed that "D. sinensis" was the same animal as "Sinosaurus triassicus" On the other hand, Wang "et al." (2017) stated that it needs to be further investigated whether "D. sinensis" is indeed a junior synonym of "S. triassicus", and noted that the two species are different at least in the anatomy of the premaxilla. The authors tentatively assigned "D. sinensis" to the genus "Sinosaurus", but retained it as a species distinct from "Sinosaurus triassicus". Specimen KMV 8701 consists of a skull (measuring 525 mm), and is nearly complete. The specimen KMV 8701 is about long, meaning "Sinosaurus" was about that length. KMV 8701 has been assigned now to "Sinosaurus", but the specimen still lacks sufficient description and preparation. In 2012, a new specimen of "Sinosaurus" was described, and was found to represent a new species.
Museum of the Rockies
Apart from housing one of the largest collections of dinosaur fossils in the world and the largest in the United States, the museum is also home to one of the world's largest "Tyrannosaurus" skulls (MOR 008) – narrowly surpassing that of the Chicago Field Museum's specimen, Sue. The museum's Siebel Dinosaur Complex, designed by curator Horner, is home to one of the first identified female dinosaurs, an ovulating "T. rex". Curator Horner, who served as an adviser to the "Jurassic Park" films, was one of the lead scientists involved in the 2005 discovery of soft tissue remains in the thigh bone of a "Tyrannosaurus", which were later brought to the museum. The museum has also been involved in a number of other finds, including a baby "Triceratops" in Jordan, Montana, in 2006, and "Yoshi's Trike" (MOR 3027), a large "Triceratops" specimen with 125 cm long horns, discovered in 2010.
Timeline of United States discoveries
Torosaurus was a herbivorous dinosaur that lived during the Late Cretaceous Period about 70 million years ago in what is now North America. Torosaurus had an enormous head that measured 8 feet (2.5 m) in length. Its skull is one of the largest know up to date, no other land animal has ever had a skull larger than Torosaurus. Torosaurus frill made up about one-half the total skull length. The first fossils of Torosaurus were discovered in 1889, in Wyoming by John Bell Hatcher. The American paleontologist Othniel Charles Marsh would later name the specimen "Torosaurus latus", in recognition of the bull-like size of its skull and its large eyebrow horns. Ever since, the specimen has been in display at the Peabody Museum in New Haven, Connecticut.
Shuangbaisaurus
"Shuangbaisaurus" had a relatively robust (compared to "Sinosaurus") skull, with a length of and a length/height ratio of 2.84, not including the thin paired crests that were present at least above the eye sockets. These crests are incompletely preserved, but appeared to have been formed mostly from the frontal bone, as well as possibly the postorbital and prefrontal bones. The crests may have extended further forward, over the nasal and lacrimal bones. Similar crests are seen in "Dilophosaurus" and "Sinosaurus"; however, the crests of "Sinosaurus" do not extend over the eyes, thus differentiating it from "Shuangbaisaurus".
Nanuqsaurus
"Nanuqsaurus" has been estimated to have been about six meters (twenty feet) long, about half the length of "Tyrannosaurus rex". This diminutive size was postulated by Fiorillo and Tykoski as being an adaptation to its high-latitude habitat.
Sinosaurus
Specimen IVPP V504, referred to "Sinosaurus", a maxilla with four teeth, was collected by Lee in the 1940s, in the Dull Purplish Beds of Shawan Member of the Lufeng Formation, that were deposited during the Hettangian stage of the Jurassic period, approximately 201-199 million years ago. Several other discoveries were made in the Shawan Member: parts of two skeletons attributed to "Sinosaurus" were discovered by Sou in 1956, specimen IVPP V279 (tooth) was discovered by C.C. Young in 1938, in dark red clayish sandstone, and specimen IVPP V381 (several teeth) was discovered by C.C. Young, in blue mudstone. The "D. sinensis" remains, KMV 8701, a nearly complete skeleton, now referred to "Sinosaurus", were recovered in the Shawan Member of Lufeng Formation. This material was discovered in 1987 in the Dull Purplish Beds that were deposited during the Hettangian stage of the Early Jurassic, approximately 201-199 million years ago.
Trix (dinosaur)
The decision to use replicas from Sue for filling several missing body parts such as the feet, was made due to Sue being roughly the same length and robusticity, and the fact that they both have been estimated to be very old for a "Tyrannosaurus". Most estimates suggest sizes from 12 (39.5 ft) to 12,5 meters in length (41 ft).
Alamosaurus
"Alamosaurus" was a gigantic quadrupedal herbivore with a long neck and tail and relatively long limbs. Its body was at least partly covered in bony armor.The total length of "Alamosaurus" is estimated to be long. Though most of the complete remains come from juvenile or small adult specimens, three fragmentary specimens, SMP VP−1625, SMP VP−1850 and SMP VP−2104, suggest that adult "Alamosaurus" could have grown to enormous sizes comparable to the largest known dinosaurs like "Argentinosaurus", which has been estimated to weigh . Scott Hartman estimates "Alamosaurus" being slightly shorter at and is equal in weight to other massive titanosaurs such as "Argentinosaurus" and "Puertasaurus". However, he says that at the moment, scientists do not know whether the massive tibia belongs to an "Alamosaurus" or a completely new species of sauropod.
Though no skull has ever been found, rod-shaped teeth have been found with "Alamosaurus" skeletons and probably belonged to this dinosaur. The vertebrae from the middle part of its tail had elongated centra. "Alamosaurus" had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from "Saltasaurus", "Malawisaurus", "Aeolosaurus", and "Gondwanatitan". "Venenosaurus" also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns. "Alamosaurus" had more robust radii than "Venenosaurus".
Saltasaurus
"Saltasaurus" was one such titanosaur sauropod, and lived around 70 million years ago. When it was first discovered, in 1975, it forced palaeontologists to reconsider some assumptions about sauropods as "Saltasaurus" possessed crocodile-like armour (osteoderms) 10 to 12 centimetres (4 to 5 in) in diameter. Previously, it had been assumed that size alone was sufficient defence for the massive sauropods. Since then, palaeontologists have investigated the possibility that other sauropods may also have had armour; for example, the Argentinian "Laplatasaurus".
Ankylosaurus
"Ankylosaurus" was the largest-known ankylosaurine dinosaur and possibly the largest ankylosaurid. In 2004 the American paleontologist Kenneth Carpenter estimated that the individual with the largest-known skull (specimen CMN 8880), which is long and wide, was about long and had a hip height of about . The smallest-known skull (specimen AMNH 5214) is long and wide, and Carpenter estimated that it measured about long and about tall at the hips. In 2017, based on comparisons with more complete ankylosaurines, the Canadian paleontologists Victoria Arbour and Jordan Mallon estimated a length of for CMN 8880 and for AMNH 5214. Though the latter is the smallest specimen of "Ankylosaurus", its skull is still larger than those of any other ankylosaurins. A few other ankylosaurs reached about in length. Because the vertebrae of AMNH 5214 are not significantly larger than those of other ankylosaurines, Arbour and Mallon considered their upper range estimate of nearly for large "Ankylosaurus" too long, and suggested a length of instead. Arbour and Mallon estimated a weight of for AMNH 5214 and tentatively estimated the weight of CMN 8880 at . Benson and colleagues also estimated the weight for the animal of AMNH 5214 at in 2014.
Dicraeosauridae
Dicraeosaurids are characterized by their relatively small body size, short necks, and long neural spines. They are 10–13 meters in body length. They share thirteen unambiguous synapomorphies including dorsal vertebrae without pleurocoels, the presence of a ventrally directed prong on the squamosal, and a subtriangular-shaped dentary symphysis.
Sinosaurus
"Dilophosaurus sinensis" was shown to be a junior synonym of "Sinosaurus" in 2003. It is possibly closer to the Antarctic theropod "Cryolophosaurus", based on the fact that the anterior end of the jugal does not participate in the internal antorbital fenestra and that the maxillary tooth row is completely in front of the eye socket. "D. sinensis" was exhibited in 1998 at Dinofest in Philadelphia. Although the skull of "D. sinensis" sports large nasolacrimal crests superficially like those reconstructed in "D. wetherilli", features elsewhere in the skeleton suggest it is closer to tetanuran theropods. Rauhut (2003) regarded "D. sinensis" as a basal tetanuran most closely related to "Sinosaurus" and "Cryolophosaurus". Lamanna "et al." (1998b) examined the material ascribed to "D. sinensis" and found it to be synonymous with "Sinosaurus triassicus". This cladistic finding was confirmed in 2003 by Dong.
Liaoningopterus
The genus is based on holotype IVPP V-13291, a crushed partial skull and skeleton including the jaws, teeth, a cervical vertebra, and bones of the finger supporting the wing. It was a large pterosaur — the largest known from China at the time of description — with a skull length estimated at 61 cm (24 in), and a wingspan estimated at five metres (16.4 ft). The skull was long and low, bearing low crests close to the tip of the beak on both lower and upper jaws. The snout crest was twelve centimetres long, was symmetrical in form and had a maximum height of seventeen millimetres. The edge of the upper jaw was very straight. The teeth were only found at the anterior end of the jaws. They were elongated but robust, generally increasing in size from the back to the front. The fourth tooth in the upper jaw is with a length of 81 millimetres the largest known for any pterosaur. It is exceptional in size compared to the other teeth of "Liaoningopterus" also, the longest tooth in the lower jaw having a length of 41 millimetres. Tooth length in the specimen is very variable, which the authors explained by the presence of recently erupted replacement teeth. There were twenty pairs of teeth in the upper jaws and thirteen or fourteen pairs in the lower jaws.
Largest organisms
The Permian era "Cotylorhynchus", from what is now the southern United States, probably was the largest of all synapsids (most of which became extinct 250 million years ago), at and 2 tonnes. The largest carnivorous synapsid was "Anteosaurus" from what is now South Africa during Middle Permian era. "Anteosaurus" was long, and weighed about .The largest living reptile, a representative of the order Crocodilia, is the saltwater crocodile ("Crocodylus porosus") of Southern Asia and Australia, with adult males being typically long. The largest confirmed saltwater crocodile on record was long, and weighed about . Unconfirmed reports of much larger crocodiles exist, but examinations of incomplete remains have never suggested a length greater than . Also, a living specimen estimated at and has been accepted by the Guinness Book of World Records. However, due to the difficulty of trapping and measuring a very large living crocodile, the accuracy of these dimensions has yet to be verified. A specimen named Lolong caught alive in the Philippines in 2011 (died February 2013) was found to have measured in length.
Pneumatoraptor
"Pneumatoraptor" differs from other theropods in having a narrow shoulder blade that is nearly circular in cross section, as well as having a large opening in the bone to house a hollow air sac cavity. The bone is small, indicating that the animal was only about half the size of the related "Sinornithosaurus" or 0.73 m (2.2 ft). The shoulder girdle is L-shaped, showing it to be a member of the group Paraves, which also includes the dromaeosaurids, troodontids, and birds. While the "Pneumatoraptor" remains are too incomplete to tell which, if any, of these specific groups it belongs to, many of the bones features are similar to dromaeosaurids.
Sigilmassasaurus
Several large theropods (more than one tonne) are known from the Cenomanian of northern Africa, raising questions about how such animals would have coexisted. Species of "Spinosaurus", the largest known theropod, has been found in both Morocco and Egypt, as has the huge "Carcharodontosaurus". Two smaller theropods, "Deltadromeus" and "Bahariasaurus", have also been found in Morocco and Egypt, respectively, and may be closely related or possibly the same genus. "Sigilmassasaurus", from Morocco, and "Spinosaurus B", from Egypt, represent a fourth type of large predator. This situation resembles that in the Late Jurassic Morrison Formation of North America, which boasts up to five theropod genera over one tonne in weight, as well as several smaller genera. Differences in head shape and body size among the large North African theropods may have been enough to allow niche partitioning as seen among the many different predator species found today in the African savanna.
Dinosaur coloration
In 2010 Dr. Mike Benton from the University of Bristol analyzed the remains of "Sinosauropteryx", "Confuciusornis", "Caudipteryx", and "Sinornithosaurus" from the Yixian and also discovered melanosomes. It was determined that "Sinosauropteryx" had orange feathers and that its tail was striped. Given the feathers were brightly colored and ill-suited for flight it is hypothesized that this species used its feathers for display. A 2017 study also reported that the body coloration of "Sinosauropteryx" extended to the face, creating a raccoon-like "mask" around the eyes.
Sinonyx
"Sinonyx" was about 1.5 m (5 ft) long, about the size of a modern grey wolf with a large elongated head, short legs and tiny hooves on all of its toes. It was built for stamina and strength and was well equipped to take care of itself by killing slower-moving prey or scavenging along sea shores. The tooth count was the primitive mammalian number (44) and the teeth were differentiated as are the heterodont teeth of today's mammals. The molars were very narrow shearing teeth, especially in the lower jaw, but possessed multiple cusps. The large skull had an extended occipital bone and large sagittal crest that contained a tiny brain. The large sagittal crest indicates a powerful bite, for these are the bones which anchor muscle to the lower jaw or mandible; with the increased surface area indicating a large muscle mass.
Pachycephalosauria
Pachycephalosaurs were bipedal ornithischians characterized by their thickened skulls. They had a bulky torso with an expanded gut cavity and broad hips, short forelimbs, long legs, a short, thick neck, and a heavy tail. Large orbits and a large optic nerve point to pachycephalosaurs having good vision, and uncharacteristically large olfactory lobes indicate that they had a good sense of smell relative to other dinosaurs.They were fairly small dinosaurs, with most falling in the range of 2–3 meters (6.6-9.8 feet) in length and the largest, "Pachycephalosaurus wyomingensis," estimated to measure 4.5 meters (14.8 feet) long and weigh 450 kilograms (990 pounds). The characteristic skull of pachycephalosaurs is a result of the fusion and thickening of the frontals and parietals, accompanied by the closing of the supratemporal fenestra. In some species this takes the form of a raised dome; in others, the skull is flat or wedge-shaped. While the flat-headed pachycephalosaurs are traditionally regarded as distinct species or even families, they may represent juveniles of dome-headed adults. All display highly ornamented jugals, squamosals, and postorbitals in the form of blunt horns and nodes. Many species are only known from skull fragments, and a complete pachycephalosaur skeleton is yet to be found.
Sinosauropteryx
The specimen NIGP 127587 was preserved with the remains of a lizard in its gut region, indicating that small, fast-moving animals made up part of the diet of "Sinosauropteryx prima". Numerous lizards of this type have been found in the same rocks as "Sinosauropteryx". These lizards have been interpreted as most likely belonging to the genus "Dalinghosaurus". "Dalinghosaurus" was probably a fast-running lizard adapted to living in open habitats, much like "Sinosauropteryx" itself.
Sauropelta
"Sauropelta" was a heavily built quadrupedal herbivore with a body length of approximately . The skull was triangular when viewed from above, with the rear end wider than the tapering snout. One skull measured 35 centimeters (13.75 in) in width at its widest point, behind the eyes. Unlike some other nodosaurids, the roof of the skull was characteristically flat, not domed. The roof of the skull was very thick and covered in flat, bony plates that are so tightly fused that there appear to be no sutures (boundaries) like the ones seen in "Panoplosaurus", "Pawpawsaurus", "Silvisaurus", and many other ankylosaurs. This could also be an artifact of preservation or preparation. As in other ankylosaurs, thick triangular scutes projected from the postorbital bone, above and behind the eyes, as well as the jugal bone, below and behind the eyes. More typically for nodosaurids, leaf-shaped teeth lined both upper and lower jaws, used for cutting plant material. The front end of the skull is unknown, but there would have been a sharp bony ridge (tomium) at the end of both upper and lower jaws, as seen in other ankylosaurs. This ridge probably would have supported a keratinous beak.
Einiosaurus
"Einiosaurus" was a herbivorous dinosaur. In 2010 Gregory S. Paul estimated its body length at 4.5 meters, its weight at 1.3 tonnes. Its snout is narrow and very pointed. It is typically portrayed with a low, strongly forward and downward curving nasal horn that resembles a bottle opener, though this may only occur in some adults. The supraorbital (over-the-eye) horns are low, short and triangular in top view if present at all, as opposed to the chasmosaurines, such as "Triceratops", which have prominent supraorbital horns. A pair of large spikes, the third epiparietals, projects backwards from the relatively small frill. Smaller osteoderms adorn the frill edge. The first epiparietals are largely absent.
Sinosauropteryx
"Sinosauropteryx" was anatomically similar to "Compsognathus", differing from its European relatives in its proportions. The skull of "Sinosauropteryx" was 15% longer than its thigh bones, unlike in "Compsognathus", where the skull and thigh bones are approximately equivalent in length. The arms of "Sinosauropteryx" (humerus and radius) were only 30% the length of its legs (thigh bone and shin), compared to 40% in "Compsognathus". Additionally, "Sinosauropteryx" had several features unique among all other theropods. It had 64 vertebrae in its tail. This high number made its tail the longest relative to body length of any theropod. Its hands were long compared to its arms, about 84% to 91% of the length of the rest of the arm (humerus and radius), and half the length of the foot. The first and second digits were about the same length, with a large claw on the first digit. The first fingers were large, being both longer and thicker than either of the bones of the forearm. The teeth differed slightly (they were heterodont) based on position: those near the tips of the upper jaws (on the premaxillae) were slender and lacked serrations, while those behind them (on the maxillae) were serrated and laterally compressed. The teeth of the lower jaws were similarly differentiated.
Coronosaurus
"Coronosaurus" is a medium-sized centrosaurine ceratopsid. Gregory S. Paul in 2010 estimated its body length at five meters, its weight at two tonnes. It had as an adult inflated supraorbital horncores — the "brow horns" above the eye sockets — but not elongated as in "Zuniceratops", chasmosaurines, and more basal centrosaurines (like "Albertaceratops" and "Diabloceratops"), that project laterally (to the sides) over the orbit. As a sub-adult its postorbital horncores are pyramidal in shape with a slight lateral inflection of the distal, upper, one half.
Sinocalliopteryx
Like many other theropods of the Yixian Formation, "Sinocalliopteryx" was preserved with "protofeathers," simple filamentous integument (hairlike structures covering the skin), very similar to that found in "Sinosauropteryx". The integument of "Sinocalliopteryx" differ in length across the body, with the longest protofeathers covering the hips, base of the tail, and back of the thighs. These longest protofeathers measured up to ten centimeters (4 in) in length. Protofeathers were also found on the metatarsus (upper part of the foot). While these were not nearly as long or modern as the corresponding feathers of "four-winged" dinosaurs such as "Microraptor" and "Pedopenna", they do indicate that foot-feathers or similar structures first arose in dinosaurs much more basal or "primitive" than previously known.
Sauropoda
Neosauropoda is quite plausibly the largest clade of dinosaurs ever to have existed, with a few exceptions. Most exceptions are hypothesized to be caused by island dwarfism, although there is a trend in Titanosauria towards a smaller body size. The titanosaurs, however, have also been some of the largest sauropods ever. Other than titanosaurs, a clade of diplodocoids, a group of giants, called Dicraeosauridae, is diagnosed by a small body size. No sauropods were very small, however, for even "dwarf" sauropods are larger than , a size reached by only about 10% of all mammalian species.
Dinosaur size
Size has been one of the most interesting aspects of dinosaur science to the general public and to scientists. Dinosaurs show some of the most extreme variations in size of any land animal group, ranging from the tiny hummingbirds, which can weigh as little as three grams, to the extinct titanosaurs, which could weigh as much as .
Sauropodomorpha
One of the earliest known sauropodomorphs, "Saturnalia", was small and slender (1.5 metres, or 5 feet long); but, by the end of the Triassic, they were the largest dinosaurs of their time, and throughout the Jurassic and Cretaceous they kept on growing. Ultimately the largest sauropods, like "Supersaurus", "Diplodocus hallorum", "Patagotitan", and "Argentinosaurus", reached in length, and 60,000–100,000 kilograms (65–110 US short tons) or more in mass.
Dinosaur Walk Museum
Parasaurolophus: The Parasaurolophus, like the T-Rex, lived during the Cretaceous Period 76-66 million years ago. It grew to be long, high, and weighed almost 7,700 pounds. The Parasauolophus was an herbivore. The large crest was thought to be used for communication amongst males and females.
Allosaurus
"Allosaurus" was a typical large theropod, having a massive skull on a short neck, a long tail and reduced forelimbs. "Allosaurus fragilis", the best-known species, had an average length of , with the largest definitive "Allosaurus" specimen (AMNH 680) estimated at long, and an estimated weight of . In his 1976 monograph on "Allosaurus", James H. Madsen mentioned a range of bone sizes which he interpreted to show a maximum length of . As with dinosaurs in general, weight estimates are debatable, and since 1980 have ranged between , , and for modal adult weight (not maximum). John Foster, a specialist on the Morrison Formation, suggests that is reasonable for large adults of "A. fragilis", but that is a closer estimate for individuals represented by the average-sized thigh bones he has measured. Using the subadult specimen nicknamed "Big Al", researchers using computer modelling arrived at a best estimate of for the individual, but by varying parameters they found a range from approximately to approximately .
Sacisaurus
"Sacisaurus" was approximately long and high. Its long and strong legs indicate that it was a fast animal. According to Jorge Ferigolo, paleontologist of Zoobothanic Foundation of Rio Grande do Sul state, the biggest teeth of the genus were just long.
Paleontology in New Mexico
In 1979, two hikers discovered a series of gigantic articulated vertebrae fossils near San Ysidro. They reported the remains to David Gilette of the New Mexico Museum of Natural History. Gillette led an expedition into the region and used cutting edge technology to locate the remains while they were still entombed in sandstone. The team excavated a massive quarry and gradually recovered a significant portion of the rear half of a diplodocid sauropod dinosaur. In 1991 this dinosaur was formally described as the new genus "Seismosaurus" and estimated to be the longest dinosaur known to science at long. In 1989, excavation began at the fossils site Rodney Peterson discovered near Albuquerque. Fossils recovered included a huge allosaurid that may be referrable to the genus "Saurophaganax", "Camarasaurus", and the skull and teeth of a diplodocid. This was the first major quarry in New Mexico to preserve a significant number of bones from a variety of dinosaur species. During the early 80s, another partial sauropod skeleton was discovered near San Ysidro. The remains were thought to belong to the species "Camarasaurus supremus". Prior to these discoveries most dinosaur fossils discovered in New Mexico were scrappy remains uncovered serenipitously by mining operations and surveys for uranium. More recently, in the 2000s, "Seismosaurus" was found to be the same as "Diplodocus", a previously known dinosaur of similar age from the western United States.
Massospondylus
"Massospondylus" was a mid-size sauropodomorph, around in length and weighed approximately 1000 kilograms (2200 lb), although a few sources have estimated its length at up to . It was a typical early sauropodomorph, with a slender body, a long neck and a proportionally very small head. 
The vertebral column was composed of nine cervical (neck) vertebrae, 13 dorsal (back) vertebrae, three sacral (hip) vertebrae, and at least 40 caudal (tail) vertebrae. The pubis faced forward, as with most saurischians. It had a slighter build than that of "Plateosaurus", an otherwise similar dinosaur. The neck was proportionally longer than in most other plateosaurids, with the foremost cervicals being four times the length of their width. The forelimbs were only half the length of the hindlimbs but quite powerful, as indicated by the broad upper end of the humerus that provided attachment areas for a large arm musculature. Like "Plateosaurus", it had five digits on each hand and foot. The hand was short and wide, with a large sickle shaped thumb claw used for feeding or defense against predators. The thumb was the longest finger in the hand, while the fourth and fifth digits were tiny, giving the forepaws a lopsided look.
Isisaurus
The type specimen of "Isisaurus colberti", ISI R 335/1-65, was originally described and named as "Titanosaurus colberti" by Sohan Lal Jain and Saswati Bandyopadhyay in 1997, the specific name honouring Edwin Harris Colbert, but was placed in its own genus, by Wilson and Upchurch, in 2003. It had a short, vertically directed neck and long forelimbs, making it considerably different from other sauropods. The humerus is 148 centimetres long. Based on this specimen, "Isisaurus" would have grown to about 18 meters (60 feet) in length and weighed about 14,000 kg (15 tons).
Dinosaur
While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines. While the dinosaurs' modern-day surviving avian lineage (birds) are generally small due to the constraints of flight, many prehistoric dinosaurs (non-avian and avian) were large-bodied—the largest sauropod dinosaurs are estimated to have reached lengths of and heights of and were the largest land animals of all time. Still, the idea that non-avian dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large, sturdy bones are more likely to last until they are fossilized. Many dinosaurs were quite small: "Xixianykus", for example, was only about long.
Aerosaurus
"Aerosaurus" has been recognized as a basal member of the Synapsida, a clade that ultimately produced mammals. Relative to the skull, the body was much larger and the ribs were deeper. The tail was unusually long for a synapsid. Overall Varanopseid pelycosaurs measure about one meter long with fewer maxillary and dentary teeth compared to other Varanops. In "Aerosaurus", the teeth were more laterally compressed creating a strong recurved shape. "Aerosaurus" cranial morphology is distinguishable with its extremely long tooth row, recurved tooth, triangular lateral temporal fenestra. The teeth were so highly curved and compressed that they seem unable to penetrate flesh and the tooth row extended far behind the orbit. The lower teeth were also relatively tiny and such an arrangement suggests "Aerosaurus" was a carnivore. Their limbs were long, and skeleton built lightly suggests they were active and agile. A long low skull and dentition extended far back to lie below the temporal fenestra. "Aerosaurus" had other general features found in ‘Pelycosaurs’ like a slanted Occiput, a lateral temporal fenestra, a septomaxilla bone that contacting the nasal and a maxilla bone contacting the quadrojugal.
New Mexico Museum of Natural History and Science
The "Jurassic Super Giants" exhibit features the complete skeletons of "Seismosaurus", "Saurophaganax", "Stegosaurus", and one leg of a "Brachiosaurus". In the museum's atrium is the skeleton of , a "Tyrannosaurus rex" measuring forty feet (≈12.2 meters) in length and twelve feet (≈3.7 meters) in height, the second largest "T. rex" ever found.
Dinosaur size
"Tyrannosaurus" was for many decades the largest theropod and best-known to the general public. Since its discovery, however, a number of other giant carnivorous dinosaurs have been described, including "Spinosaurus", "Carcharodontosaurus", and "Giganotosaurus". These large theropod dinosaurs rivaled or even exceeded "Tyrannosaurus" in size, though more recent studies show some indication that "Tyrannosaurus", although shorter, was the heavier predator. There is still no clear explanation for exactly why these animals grew so much larger than the land predators that came before and after them.
Venenosaurus
Venenosaurus ( ) was a sauropod dinosaur, named after the Poison Strip Member of the Cedar Mountain Formation in Utah, United States, where the fossils were discovered by a Denver Museum of Natural History volunteer Tony DiCroce in 1998. "Venenosaurus dicrocei" was first described as a new species in 2001 by Virginia Tidwell, Kenneth Carpenter, and Suzanne Meyer. "Venenosaurus" is a relatively small (probably around 10 m (33 ft) long) titanosauriform sauropod, known from an incomplete skeleton of an adult and a juvenile. The holotype is DMNH 40932 Denver Museum of Natural History. The specimen consisted of tail vertebrae, the left scapula, right radius, left ulna, metacarpals, forefoot phalanges, right pubis, left and right ischia, metatarsals, chevrons, and ribs.
Scymnosaurus
"Scymnosaurs" are estimated to have been approximately the size of the modern day hyena, and possess teeth suggesting that they were carnivorous. S. Ferox was initially described as the second largest Therocephalian to "Titanosaurus", until the discovery of "S." "Major", which is likely the largest Therocephalian.
Tyrannosauridae
Although descended from smaller ancestors, tyrannosaurids were almost always the largest predators in their respective ecosystems, putting them at the apex of the food chain. The largest species was "Tyrannosaurus rex", one of the largest known land predators, which measured up to in length and according to most modern estimates to in weight. Tyrannosaurids were bipedal carnivores with massive skulls filled with large teeth. Despite their large size, their legs were long and proportioned for fast movement. In contrast, their arms were very small, bearing only two functional digits.
Pinacosaurus
"Pinacosaurus" was about five metres long and weighed up to two tonnes. Its body was flat and low-slung but not as heavily built as in some other members of the Ankylosaurinae. The head was protected by bone tiles, hence its name. Each nostril was formed as a large depression pierced by between three and five smaller holes, the purpose of which is uncertain. A smooth beak bit off low-growing plants that were sliced by rows of small teeth and then swallowed to be processed by the enormous hind gut. Neck, back and tail were protected by an armour of keeled osteoderms. The animal could also actively defend itself by means of a tail club.
Siroccopteryx
The wingspan of this large pterosaur should be four to five meters. It is likely that this animal was a specialized glider, and ventured into the sea off the coast of Africa, to capture fishes and other prey that swim near the surface.
Sinosauropteryx
The first fossil specimen of the dinosaur later named "Sinosauropteryx prima" was uncovered in August 1996 by Li Yumin. Yumin was a farmer and part-time fossil hunter who often prospected around Liaoning Province to acquire fossils to sell to individuals and museums. Yumin recognized the unique quality of the specimen, which was separated into two slabs, and sold the slabs to two separate museums in China: the National Geological Museum in Beijing, and the Nanjing Institute of Geology and Paleontology. The director of the Beijing museum, Ji Qiang, recognized the importance of the find, as did visiting Canadian palaeontologist Phil Currie and artist Michael Skrepnick, who became aware of the fossil by chance as they explored the Beijing museum's collections after leading a fossil tour of the area during the first week of October, 1996. Currie recognized the significance of the fossil immediately. As "The New York Times" quoted him, "When I saw this slab of silt stone mixed with volcanic ash in which the creature is embedded, I was bowled over." When originally described, the authors named "Sinosauropteryx", meaning "Chinese Reptilian Wing".
Charonosaurus
"Charonosaurus" is a very large lambeosaurine hadrosaur (estimated around 10 m (33 ft) long), known from a partial skull (Holotype: CUST J-V1251-57 (Changchun University of Sciences and Technology, Changchun, Jilin Province, China) found in the Late Maastrichtian Yuliangze Formation, west of Jiayin village, Heilongjiang Province, northeastern China. Adult and juvenile hadrosaur remains discovered in the same area and formation likely represent the same taxon and supply information on most of the postcranial skeleton; the femur length was up to 1.35 m. (4.5 ft). The partial skull resembles that of "Parasaurolophus" and probably had a similar long, backward-projecting hollow crest, indicated by the highly modified dorsal surface of the frontal bones. "Charonosaurus" is one of the largest hadrosaurs currently known from Asia and indicates that lambeosaurines survived until the very end of the Cretaceous (lambeosaurines are not known from the Late Maastrichtian in North America).
Dilophosaurus
"Dilophosaurus" was one of the earliest large predatory dinosaurs, a medium-sized theropod, though small compared to some of the later theropods. Slender and lightly built, its size was comparable to that of a brown bear. The largest known specimen weighed about , measured about in length, and its skull was long. The smaller holotype specimen weighed about , was long, with a hip height of about , and its skull was long. A resting trace of a theropod similar to "Dilophosaurus" and "Liliensternus" has been interpreted by some researchers as showing impressions of feathers around the belly and feet, similar to down. Other researchers instead interpret these impressions as sedimentological artifacts created as the dinosaur moved, though this interpretation does not rule out that the track-maker could have borne feathers.
Sinocalliopteryx
While similar to the related "Huaxiagnathus", "Sinocalliopteryx" were larger. The type specimen, at 2.37 meters (7.78 ft) in length, in 2007 was the largest known compsognathid exemplar. In 2012 an even larger specimen was reported.
Puertasaurus
Due to a lack of better material, the size of "Puertasaurus" is difficult to estimate. Novas estimated the new species was approximately long and weighing between . This would place it as one of the largest dinosaurs, only rivaled in size by its relative "Argentinosaurus", which has been estimated at up to in length and in mass. The discovery of the more complete "Futalognkosaurus" revealed these previous estimates were likely too high. In 2012, Thomas Holtz estimated "Puertasaurus" to have been potentially long. In 2013, the entire neck was estimated to have been approximately long by Mike Taylor and Matt Wedel. Later the same year, Scott Hartman made a reconstruction that suggests a total length of , slightly shorter than other estimates. In 2016, Gregory S. Paul estimated a length of and a weight of at least . In 2017, paleontologist José Carballido and his colleagues estimated its mass at roughly , which was lighter than "Patagotitan", a more complete giant sauropod.
Austroraptor
Considered large for a dromaeosaur, "Austroraptor cabazai" measured about in length from head to tail. In 2010, Gregory S. Paul estimated its length at 6 metres, its weight at 661.387 pounds or 300 kilograms. It is the largest dromaeosaur to be discovered in the Southern Hemisphere. The type specimen, labeled MML-195, consisted of a fragmentary skeleton including parts of the dinosaur's skull, the lower jaws, a few neck and torso vertebrae, some ribs, a humerus, and assorted bones from both legs. However little of the entire skeleton was found, what bones were available for analysis expressed some distinct characteristics that differentiate "Austroraptor" from other dromaeosaurs. "A. cabazai"'s 80 centimeter-long skull was low and elongated, much more so than that of other dromaeosaurs. Several of its skull bones bore some resemblance to that of the smaller troodontid deinonychosaurs. The front limbs of this taxon were short for a dromaeosaur, with its humerus less than half the length of its femur. Among the Dromaeodauridae, only this genus, "Tianyuraptor", "Zhenyuanlong" and "Mahakala" have similarly reduced forelimbs. The relative length of its arms has caused "Austroraptor" to be compared to another, more famous short-armed dinosaur, "Tyrannosaurus".
Compsognathidae
The other genera in this family are slightly larger than "Compsognathus longipes", but generally similar in size. The largest member of the family Compsognathidae is "Huaxiagnathus", which is estimated from its holotype to be around 5.9 m in length. "Sinocalliopteryx" measures around 2.4 m in length. "Sinosauropteryx" is the most similar to "Compsognathus", measuring at 1.07 m in length at most.
Segisaurus
"Segisaurus" lived about 183 million years ago during the Jurassic period. "Segisaurus" was roughly the size of a goose and was a primitive bipedal theropod. "Segisaurus" was roughly 1 meter (3.3 feet) long, half a meter (1.65 feet) tall and weighed about 4-7 kilograms. It was nimble and insectivorous, although it may have scavenged meat also. It was bird-like in structure, with a flexible, elongated neck and stout body. "Segisaurus" was three-toed and had powerful legs that were long compared to its body length. Like its legs, "Segisaurus" had a long tail and long forearms. Its collar bone was not unlike a bird's, thus strengthening scientists' arguments that dinosaurs were related to avians. "Segisaurus" is described from the only specimen ever found, the holotype UCMP 32101, which was a sub-adult. The full size of "Segisaurus" as an adult may never be known. Strangely, clavicles were found on the "Segisaurus" specimen, which were unknown in other dinosaurs from that era. A speculative interpretation by Charles Lewis Camp was that the "splint-like" neck ribs supported a "Draco"-like patagium along the neck, to improve the animal's ability to move quickly. "Segisaurus" is significant because it demonstrates that the clavicle was primitively present in early theropods.
Animantarx
Animantarx ( ; meaning 'living citadel') is a genus of nodosaurid ankylosaurian dinosaur from the Upper Cretaceous of western North America. Like other nodosaurs, it would have been a slow-moving quadrupedal herbivore covered in heavy armor scutes, but without a tail club. The skull measures approximately 25 cm (10 inches) in length, suggesting the animal as a whole was no more than 3 meters (10 feet) long.
Sinopterus
Sinopterus (meaning "Chinese wing") was a genus of tapejarid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China. It was first described and named by Wang Xiaolin and Zhou Zhonghe. Three species have been classified in this genus, though only two are generally considered to be valid. "Sinopterus" is known for its proportionally large skull, which has a birdlike pointed beak, a long bony crest that starts with a tall premaxilla and goes back along the middle of the skull to form a point overhanging the rear of the skull, and its lack of teeth.
Corythosaurus
Benson "et al." (2012) estimated that "Corythosaurus" has an average length of . Richard Swann Lull's earlier length estimate, published in 1942, found a slightly longer total length of , a size similar to "Lambeosaurus lambei", another Canadian lambeosaurine. In 1962, Edwin H. Colbert used models of specific dinosaurs, including "Corythosaurus", to estimate their weight. The "Corythosaurus" model used, was modelled by Vincent Fusco after a mounted skeleton, and supervised by Barnum Brown. After testing, it was concluded that the average weight of "Corythosaurus" was . More recent size estimates of "Corythosaurus", published in 2001, find the genus to be among the largest hadrosaurids, only smaller than "Shantungosaurus" and "Parasaurolophus". The total length of "Corythosaurus" specimen AMNH 5240 was found to be , with a weight of .
Spinosaurus
François Therrien and Donald Henderson, in 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 , their estimates include a body length of and a body mass of . The lower estimates for "Spinosaurus" would imply that 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 in length. Improvement of the precision of size estimates for "Spinosaurus" requires the discovery of more complete remains as available for some other dinosaurs, especially the limb bones of "Spinosaurus" which are "hitherto unknown".
Sillosuchus
However, other remains indicate that it could grow much larger. Most notable among additional remains was PVL 2267, an isolated cervical (neck vertebra) initially misidentified as belonging to the giant quadrupedal predator "Saurosuchus," a distant relative of "Sillosuchus". This bone was 20 centimeters (8 inches) long, while cervicals from the holotype were only 8 centimeters (3 inches) long. Using its more complete relatives to estimate length, this bone likely belonged to a "Sillosuchus" that was 9-10 meters (30-33 feet) in length. This would indicate that "Sillosuchus" was among the largest terrestrial pseudosuchians (crocodilian-line archosaurs).
Dinosaur size
There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. Most of the largest herbivorous specimens on record were discovered in the 1970s or later, and include the massive titanosaur "Argentinosaurus huinculensis", which is the largest dinosaur known from uncontroversial evidence, estimated to have been and long. Some of the longest sauropods were those with exceptionally long, whip-like tails, such as the "Diplodocus hallorum" (formerly "Seismosaurus") and the 33- to 35-metre-long (108–115 ft) "Supersaurus". The tallest was the "Brachiosaurus".
Tylosaurinae
Lingham-Soliar suggested that tylosaurines were not among the fastest swimming nor the strongest mosasaurids. However, they are lightly built, having greatly reduced the weight of their bodies and possessing relatively small pectoral and pelvic girdles, fore- and hindlimbs. Their bone is highly cancellous and may have been impregated with fat cells during life, adding buoyancy. These traits suggest that tylosaurs may have been ambush predators. Tylosaurs were among the largest mosasaurs, with some species of "Tylosaurus" and "Hainosaurus" reaching lengths of 9-12+ meters, making them among the largest of all marine reptiles.
Tsintaosaurus
Tsintaosaurus (; meaning "Qingdao lizard", after the old transliteration "Tsingtao") is a genus of hadrosaurid dinosaur from China. It was about long and weighed 2.5 tonnes. The type species is "Tsintaosaurus spinorhinus", first described by Chinese paleontologist C. C. Young in 1958.
Dinosaur size
In 2014, the fossilized remains of a previously unknown species of sauropod were discovered in Argentina. The titanosaur, named "Patagotitan", would have been around 40m long and weighed around 77 tonnes, larger than any other previously found sauropod. The specimens found were remarkably complete, significantly more so than previous titanosaurs. Research as of 2017 estimated "Patagotitan mayorum" to have been long
Sinosauropteryx
"Sinosauropteryx", as a Yixian Formation dinosaur, is a member of the Jehol Biota, the assemblage of organisms found in the Yixian Formation and overlying Jiufotang Formation. The Yixian Formation is composed largely of volcanic rocks such as andesite and basalt. Between the volcanic layers are several beds of sedimentary rocks representing deposition in a lake. The freshwater lake strata of the Yixian Formation have preserved a wide variety of plants, invertebrates, and vertebrates. Gymnosperm forests were extensive, with a few early flowering plants as well. Ostracods and insects were diverse, and bivalves and gastropods were abundant. Mammals and birds are also well-known from the formation. The setting was subject to periodic mortality events including volcanic eruptions, wildfires, and noxious gases erupting from the lakes. The climate has been interpreted as temperate, with distinct wet and dry seasons. The yearly temperature during this time period averaged about , indicating a temperate climate with unusually cold winters for the generally warm Mesozoic era, possibly due to northern China's high latitude during this time.
Styracosaurus
The first fossil remains of "Styracosaurus" were collected in Alberta, Canada by C.M. Sternberg (from an area now known as Dinosaur Provincial Park, in a formation now called the Dinosaur Park Formation) and named by Lawrence Lambe in 1913. This quarry was revisited in 1935 by a Royal Ontario Museum crew who found the missing lower jaws and most of the skeleton. These fossils indicate that "S. albertensis" was around 5.5 to 5.8 meters in length and stood about 1.65 meters high at the hips. An unusual feature of this first skull is that the smallest frill spike on the left side is partially overlapped at its base by the next spike. It appears that the frill suffered a break at this point in life and was shortened by about . The normal shape of this area is unknown because the corresponding area of the right side of the frill was not recovered.
Sue (dinosaur)
The largest "T. rex" specimen discovered, Sue has a length of , stands tall at the hips, and has been estimated at between as of 2018. In 2011, other size estimates were between , although the authors stated that their upper and lower estimates were based on models with wide possible errors, and that they "consider them [these extremes] to be too skinny, too fat, or too disproportionate". A further estimate portrayed a leaner build, placing the specimen at , while others placed this specimen as low as in weight. Displayed separately from the whole body, the skull weighs .
Allosaurus
In 1991 "Big Al" (MOR 693), a 95% complete, partially articulated specimen of "Allosaurus" was discovered. It measured about 8 meters (about 26 ft) in length. MOR 693 was excavated near Shell, Wyoming, by a joint Museum of the Rockies and University of Wyoming Geological Museum team. This skeleton was discovered by a Swiss team, led by Kirby Siber. In 1996 the same team discovered a second "Allosaurus", "Big Al Two", which is the best preserved skeleton of its kind to date.
Cetiosaurus
"Cetiosaurus would of reached lengths of 14-18 meters making it the largest dinosaurs to Rome Europe until 156 million years ago (late Jurassic period)" . Its neck was moderately long; no longer than its body. The tail was considerably longer, consisting of at least forty caudal vertebrae. Its dorsal vertebrae, the bones along the back, had the original heavy build with limited air chambers, unlike the extremely hollowed-out bones of later sauropods like "Brachiosaurus". Its forearm was as long as the upper arm, unlike most other sauropods, resulting in a forelimb equalling the hindlimb in length. Its thigh bone was approximately six feet long.
In his original descriptions, Owen was unable to indicate any differences between "Cetiosaurus" and other sauropods for the simple reason these latter were not yet discovered. Now that such relatives have been found, the uniqueness of "Cetiosaurus oxoniensis" and its status as a valid taxon must be proven by indicating its new derived traits or autapomorphies. In their 2003 revision of the genus, Upchurch & Martin identified five autapomorphies of "C. oxoniensis". The rear neck vertebrae and the front back vertebrae have spines on their tops that are low, symmetrical and in the shape of a pyramid. With the spines of all back vertebrae a ridge is absent between the spine and the diapophysis, the top rib joint; it has been lost or perhaps fused with the ridge running between the spine and the postzygapophysis, the rear joint process. The vertebrae of the middle tail have a tongue-shaped process at the top of the front face of the vertebral body; this is an extension of the floor of the neural canal. The chevrons of the front tail vertebrae have shafts of which the lower ends are flattened from the front to the rear instead of transversely. The lower process of the ilium, to which the pubic bone was attached, features on the outer surface of its base a triangular depression.
Sinomastodon
The animal was very similar to modern elephants with size ranging from 3.6 to 5.3 m. Several species are known from China, the best known being "S. hanjiangensis" from the Late Miocene and Early Pliocene of the Shanxi province. It is known from an incomplete skeleton of an adult (measuring 5.3 m) including maxilla, mandibles, teeth, tusks and other materials have been discovered. The Japanese species "S. sendaicus" described in 1924 from dentary materials from Pliocene deposits has been ascribed to the genus, as well as the species "S. bumiajuensis" (formerly "Tetralophodon") from the late Pliocene of Java. One individual of "S. hanjiangensis" was a 30-year-old tall and weighed .
Tyrannosaurus
The identification of several specimens as juvenile "Tyrannosaurus rex" has allowed scientists to document ontogenetic changes in the species, estimate the lifespan, and determine how quickly the animals would have grown. The smallest known individual (LACM 28471, the "Jordan theropod") is estimated to have weighed only , while the largest, such as FMNH PR2081 (Sue) most likely weighed about . Histologic analysis of "Tyrannosaurus rex" bones showed LACM 28471 had aged only 2 years when it died, while Sue was 28 years old, an age which may have been close to the maximum for the species.
Yingshanosaurus
"Yingshanosaurus" had a pair of about eighty centimetres long wing-like spines on its shoulders, similar in shape and relative size to those of "Gigantspinosaurus". The shoulder spine has a large flat trapezoidal base; after a sudden kink, a more narrow straight shaft, flat but with a protruding ridge on the outer side, projects to behind from the lower base edge. The bony plates on its back were rather small and relatively low, triangular or fin-shaped. The largest plates, about fifteen centimetres high and with a base length of twenty centimetres, are similar in profile to those of "Hesperosaurus", though of a more reduced relative size. They were not "splates", i.e. featuring a thickened middle section, but almost uniformly flat, with a rough and veined surface.
Giganotosaurus
"Giganotosaurus" is thought to have been one of the largest theropod dinosaurs, but the incompleteness of its remains have made it difficult to estimate its size reliably. It is therefore impossible to determine with certainty whether it was larger than "Tyrannosaurus", for example, which has been considered the largest theropod historically. Different size estimates have been reached by several researchers, based on various methods, and depending on how the missing parts of the skeleton have been reconstructed. Length estimates for the holotype specimen have varied between , with a skull between long, a femur (thigh bone) between long, and a weight between . Fusion of sutures (joints) in the braincase indicates the holotype specimen was a mature individual. A second specimen, consisting of a dentary bone (part of the lower jaw) from a supposedly larger individual, has been used to extrapolate a length of , a skull long, and a weight of . Some writers have considered the largest size estimates for both specimens exaggerated. "Giganotosaurus" has been compared to an oversized version of the well-known genus "Allosaurus".
China Dinosaurs Park
China Dinosaurs Park (), also called China Dinosaurs Land is a theme park located in Changzhou, Jiangsu, China. It has been open since September 2000. The park covers more than 600 mu (0.27 km). As it is a theme park about dinosaurs, it is also called the "Eastern Jurassic Park". The museum contains a nearly complete fossil skeleton of the important dinosaur genus "Sinosauropteryx" (similar to "Archaeopteryx") as well as large fossils such as those of a "Brachiosaurus" and a "Hadrosaurus".
Shuangbaisaurus
A further issue in the relation between "Shuangbaisaurus" and "Sinosaurus" involves the taxonomic convolution that has befallen "Sinosaurus". At least one species is recognized in the genus, "Sinosaurus triassicus", consisting of specimens LFGT LDM-L10 and LFGT ZLJT01; another specimen, KMV 8701, originally named "Dilophosaurus" "sinensis", has been referred to either "S. triassicus" or a second species "S. sinensis". KMV 8701 approaches "Shuangbaisaurus" more closely in its tall skull and premaxilla than specimens referred to "S. triassicus". Wang "et al." elected to retain "S. sinensis" as a separate species owing to these differences. No phylogenetic analysis has been conducted to quantitatively determine the relationships of "Shuangbaisaurus".
Gigantoraptor
In a quarry at Saihangaobi, in Sonid Left Banner (Inner Mongolia), numerous remains of the sauropod "Sonidosaurus" have been uncovered since 2001. Chinese paleontologist Xu Xing was asked to reenact the discovery of "Sonidosaurus" in April 2005 for a Japanese documentary. Xu obliged them by digging out a thighbone. As he wiped the bone clean, he suddenly realized it was not from a sauropod, but from an unidentified theropod in the size class of "Albertosaurus". He then stopped the filming to secure the serendipitous find. This way, the discovery of the "Gigantoraptor" holotype fossil was documented on film.
Sauropoda
Among the smallest sauropods were the primitive "Ohmdenosaurus" (4 m, or 13 ft long), the dwarf titanosaur "Magyarosaurus" (6 m or 20 ft long), and the dwarf brachiosaurid "Europasaurus", which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of insular dwarfism occurring in a population of sauropods isolated on an island of the late Jurassic in what is now the Langenberg area of northern Germany. The diplodocoid sauropod "Brachytrachelopan" was the shortest member of its group because of its unusually short neck. Unlike other sauropods, whose necks could grow to up to four times the length of their backs, the neck of "Brachytrachelopan" was shorter than its backbone.
Notocolossus
The evidence suggests that "Notocolossus" was among the largest titanosaurs, and therefore one of the heaviest land animals, yet discovered. Although the incompleteness of the skeleton of the new sauropod has prevented scientists from making precise estimates of its size, its humerus, or upper arm bone, is 1.76 m (5 ft 9 in) in length, which is longer than that of any other titanosaur for which this bone is known, including other giants such as "Dreadnoughtus", "Futalognkosaurus", and "Paralititan". If, as is likely, the body proportions of "Notocolossus" were comparable to those of better preserved titanosaurs, the new dinosaur may have weighed in the range of , most likely .
Pinacosaurus
The holotype, AMNH 6523, was found in a layer of the Djadokhta Formation, dating from the Campanian. It consists of a partially crushed skull, lower jaws, the first two neck vertebrae, and dermal bones collected in 1923. The skull is still the largest known of the genus.
"Pinacosaurus" is the best known Asian or worldwide ankylosaur with numerous specimens having been discovered. From the original Flaming Cliffs or Shabarakh Usu several other fossils have been reported including ZPAL MgD II/1: a nearly complete skeleton; ZPAL MgD II/9: a postcranial skeleton; ZPAL MgD II/31: the handle of a tail club; and PIN 3780/3: a skull; PIN 614: a nearly complete postcranial skeleton (= "Syrmosaurus viminocaudus"); and possibly MPC 100/1305, a postcranial skeleton erroneously described in 2011 as belonging to "Saichania". At another site, Alag Teeg, entire bonebeds have been uncovered of juvenile animals. Soviet-Mongolian expeditions in 1969 and 1970 reported thirty skeletons. Mongolian-Japanese expeditions added another thirty between 1993 and 1998. Forty were reported by Canadian expeditions between 2001 and 2006. The remains have not been all dug up and it is possible the reports partly pertain to the same material. In Inner Mongolia at Bayan Mandahu, the Canada−China Dinosaur Project in 1987, 1988, and 1990 found specimens IVPP V16853: a skull with cervical halfrings; IVPP V16283: a partial skull, IVPP V16854: a nearly complete skeleton; IVPP V16346: a partial skull; and IVPP V16855: a skeleton. Other, as yet undescribed material included two finds of several juveniles huddled together, evidently killed by a sandstorm (Jerzykiewicz, 1993; Burns et al., 2011). Whereas ankylosaur skeletons have often been preserved laying on their back, most "Pinacosaurus" juveniles are found on their belly in a resting position, with the legs tucked in.
Because of the many finds, in principle the entire juvenile skeleton is known. "Pinacosaurus" especially provides information on the build of the ankylosaurian skull, as in the juveniles the head armour has not yet fused with the skull proper and the sutures of the various elements are still visible. Modern studies have not yet fully covered the abundance of data. A well-preserved juvenile skull was described by Teresa Maryańska in 1971 and 1977. In 2003, Robert Hill studied the juvenile specimen IGM 100/1014 (Hill, 2003). In 2011, Currie published a study on the hand and foot, body parts often incompletely known with other ankylosaurs. The same year Michael Burns dedicated an article to four juveniles from the Bayan Mandahu (). Also in 2011, the postcranial skeleton MPC 100/1305 was described in detail, though at the time referred to "Saichania". Most recently, Michael Burns and colleagues described and illustrated the original Alag Teeg material from the Soviet-Mongolian expeditions in 1969 and 1970.
World's Largest Dinosaur
The "World's Largest Dinosaur" is the name of a model "Tyrannosaurus rex" located in the town of Drumheller in the Canadian province of Alberta. Built of fiberglass and steel, has a height of and a length of , considerably larger than the largest known specimens of the actual dinosaur which reached up to in length, and was up to tall at the hips. The dinosaur was built while former mayor Phil Bryant was in his term.
Titanosaurus
"Titanosaurus" is estimated to have grown up to 9–12 metres (30–40 ft) long and up to approximately 13 tons in weight. Wilson and Upchurch (2003) treated "Titanosaurus" as a "nomen dubium" ("dubious name") because they noted that the original "Titanosaurus" specimens cannot be distinguished from those of related animals.
Savannasaurus
"Savannasaurus" was a medium-sized titanosaur about in length. The sacrum and the fused ischium-pubis complex are both over one metre in width at their narrowest points, making "Savannasaurus" an unusually wide-bodied titanosaur. In addition to this, the describers identified several other distinguishing characteristics: the first few caudal vertebrae have shallow pits, or fossae, in their sides, a feature that was previously only known among brachiosaurids; the edges of the sternal plates are straight, not kidney-shaped like other titanosaurs; the end of the fourth metacarpal is hourglass-shaped; there is a ridge on the side of the pubis extending forward and downward from the obturator foramen; and the astragalus is taller than it is wide or long.
Borealosaurus
The type and only species is "Borealosaurus wimani", based on fragmentary remains from the Sunjiawan Formation of Liaoning. It has been estimated that this creature measured 12 metres in length, with a weight of 10 tonnes. The morphology of a mid-distal caudal vertebra was considered suggestive of a relationship with the Mongolian titanosaur "Opisthocoelicaudia". However, in their overview of Cretaceous sauropod remains from Central Asia, Averianov and Sues considered "Borealosaurus" a non-lithostrotian titanosaur due to the lack of procoely in the middle caudal vertebrae.
Rinconsaurus
Like all sauropods, "Rinconsaurus" was a large long-necked quadrupedal animal, with a long, whip-like tail and four pillar-like legs. "Rinconsaurus" was an unusually slender sauropod. Although fossil discoveries are incomplete, and no complete necks or heads have been found, fully grown "Rinconsaurus" are estimated to have been 11 meters (36 ft) long and approximately 2.5 meters (8 ft) high at the shoulder. Though only a portion of one skull has been recovered, "Rinconsaurus" may have had a long, narrow skull, based on fossil evidence of the skulls of related titanosaurs.
Specimens of Tyrannosaurus
In 1988, local rancher Kathy Wankel discovered another "Tyrannosaurus rex" in Hell Creek sediments on an island in the Charles M. Russell National Wildlife Refuge of Montana. This specimen was excavated by a team from the Museum of the Rockies led by paleontologist Jack Horner, with assistance from the U.S. Army Corps of Engineers. The specimen, given the number MOR 555 but informally called the "Wankel rex," includes approximately 46 percent of the skeleton, including the skull, as well as what at the time was the first complete "T. rex" forelimb. It has a recently estimated length of around 11.6 meters (38 ft) and a weight between and in newer figures, being the average estimate. It was long on exhibit at the Museum of the Rockies in Bozeman, Montana. Casts of MOR 555 are on display at the National Museum of Scotland, the Australian Fossil and Mineral Museum, and the University of California Museum of Paleontology. A bronze cast of the specimen, known as "Big Mike", stands outside the Museum of the Rockies.
Gojirasaurus
"Gojirasaurus" is one of the largest meat-eating dinosaurs known from the Triassic Period, almost the size of its relative, the large coelophysoid "Dilophosaurus". The size of its tibia was 469 mm, which was comparable to that of "Liliensternus" (409 mm) and "Dilophosaurus" (555 mm), suggesting that it was a large triassic dinosaur, estimated to be about 5.5 m (18 ft) long, which can be extrapolated to a weight of approximately 150–200 kg (330–440 lb). Carpenter (1997) pointed to features of the pelvis and ankle suggesting that this was an immature individual, and could therefore have grown to even a larger size in maturity. Specimen NMMNH P-4666, which consists of only a pubis, was referred to this genus by Hunt in 1994.
Largest prehistoric animals
The largest-known ichthyosaur was "Shastasaurus sikanniensis" at in length. In April 2018, paleontologists announced the discovery of a previously unknown ichthyosaur that may have reached lengths of 26 m (85 ft)- 30 m (100 feet long) making it one of the largest animals known, rivaling the Blue Whale in size. Another giant Ichthyosaur was found as well and it was larger than Lilstock Monster, possibly surpassing Blue Whale in size.The heavy built "Moradisaurus grandis", with a length of , is the largest known captorhinid.
Nipponosaurus
The immature holotype specimen measures roughly four meters (13 feet) in length. When it was originally described, it was considered to be an adult, because of its co-ossified sacral vertebra. Future authors doubted this, merely citing its small size. In the 2004 redescription, it was examined more closely and several characteristics were found that identified it as an juvenile individual. Later, in 2017, another team re-evaluated the specimen, and determined through investigating the fossils at a microscopic level (in a process called histology) that this was correct, although they doubted the significance of some of the characters identified in the former study.
Tyrannosaurus
"Tyrannosaurus rex" was one of the largest land carnivores of all time; the largest complete specimen, located at the Field Museum of Natural History under the name FMNH PR2081 and nicknamed Sue, measured long, and was tall at the hips, and according to the most recent studies estimated to have weighed between to when alive. Not every adult "Tyrannosaurus" specimen recovered is as big. Historically average adult mass estimates have varied widely over the years, from as low as , to more than , with most modern estimates ranging between and .
The neck of "Tyrannosaurus rex" formed a natural S-shaped curve like that of other theropods, but was short and muscular to support the massive head. The forelimbs had only two clawed fingers, along with an additional small metacarpal representing the remnant of a third digit. In contrast the hind limbs were among the longest in proportion to body size of any theropod. The tail was heavy and long, sometimes containing over forty vertebrae, in order to balance the massive head and torso and to provide space for massive locomotor muscles. To compensate for the immense bulk of the animal, many bones throughout the skeleton were hollowed, reducing its weight without significant loss of strength.
Ceratosaurus
"Ceratosaurus" followed the body plan typical for large theropod dinosaurs. A biped, it moved on powerful hind legs, while its arms were reduced in size. Specimen USNM 4735, the first discovered skeleton and holotype of "Ceratosaurus nasicornis", was an individual or in length according to separate sources. Whether this animal was fully grown is not clear. Othniel Charles Marsh, in 1884, suggested that this specimen weighed about half as much as the contemporary "Allosaurus". In more recent accounts, this was revised to , , or . Three additional skeletons discovered in the latter half of the 20th century were substantially larger. The first of these, UMNH VP 5278, was informally estimated by James Madsen to have been around long, but was later estimated at in length. Its weight was calculated at , , and in separate works. The second skeleton, MWC 1, was somewhat smaller than UMNH VP 5278 and might have been in weight. The third, yet undescribed, specimen BYUVP 12893 was claimed to be the largest yet discovered, although estimates have not been published. Another specimen (ML 352), discovered in Portugal in 2000, was estimated at in length and in weight.
The exact number of vertebrae is unknown due to several gaps in the spine of the "Ceratosaurus nasicornis" holotype. At least 20 vertebrae formed the neck and back in front of the sacrum. In the middle portion of the neck, the (bodies) of the vertebrae were as long as they were tall, while in the front and rear portions of the neck, the centra were shorter than their height. The upwards projecting were comparatively large, and in the dorsal (back) vertebrae, were as tall as the vertebral centra were long. The sacrum, consisting of six fused , was arched upwards, with its vertebral centra strongly reduced in height in its middle portion, as is the case in some other ceratosaurians. The tail comprised around 50 and was about half of the animal's total length; in the holotype, it was estimated at . The tail was deep from top to bottom due to its high neural spines and elongated chevrons, bones located below the vertebral centra. As in other dinosaurs, it counterbalanced the body and contained the massive caudofemoralis muscle, which was responsible for forward thrust during locomotion, pulling the upper thigh backwards when contracted.
The scapula (shoulder blade) was fused with the coracoid, forming a single bone without any visible demarcation between the two original elements. The "C. nasicornis" holotype was found with an articulated left fore limb including an incomplete (hand). Although during preparation, a cast had been made of the fossil beforehand to document the original relative positions of the bones. Carpal bones were not known from any specimen, leading some authors to suggest that they were lost in the genus. In a 2016 paper, Matthew Carrano and Jonah Choiniere suggested that one or more cartilaginous (not bony) carpals were probably present, as indicated by a gap present between the forearm bones and the metacarpals, as well as by the surface texture within this gap seen in the cast. In contrast to most more-derived theropods, which showed only three digits on each manus (digits I–III), "Ceratosaurus" retained four digits, with digit IV reduced in size. The first and fourth metacarpals were short, while the second was slightly longer than the third. The metacarpus and especially the first phalanges were proportionally very short, unlike in most other basal theropods. Only the first phalanges of digits II, III, and IV are preserved in the holotype; the total number of phalanges and unguals (claw bones) is unknown. The anatomy of metacarpal I indicates that phalanges had originally been present on this digit, as well. The pes (foot) consisted of three weight-bearing digits, numbered II–IV. Digit I, which in theropods is usually reduced to a dewclaw that does not touch the ground, is not preserved in the holotype. Marsh, in his original 1884 description, assumed that this digit was lost in "Ceratosaurus", but Charles Gilmore, in his 1920 monograph, noted an attachment area on the second metatarsal demonstrating the presence of this digit.
Spinosauridae
Baryonychines have been found in Africa, with "Suchomimus" and "Cristatusaurus," as well as in Europe, with "Baryonyx" and "Suchosaurus". "Baryonyx-"like teeth are also reported from the Ashdown Sands of Sussex, in England, and the Burgos Province, in Spain. A partial skeleton and many fossil teeth indicate spinosaurids were widespread in Asia. As of 2012, three have been named: "Ichthyovenator," "Siamosaurus" and ""Sinopliosaurus" fusuiensis". In 2014, a spinosaurid tooth was discovered in Malaysia; the first dinosaur remains discovered in the country. At la Cantalera-1, a site in the Early Barremanian Blesa Formation in Treul, Spain, two types of spinosaurid teeth were found, and they were assigned, tentatively, as indeterminate spinosaurine and baryonychine taxa. An intermediate spinosaurid was discovered in the Early Cretaceous Eumeralla Formation, Australia. It is known from a single 4 cm long partial cervical vertebra, designated NMV P221081. It is missing most of the neural arch. The specimen is from a juvenile estimated to be about 2 to 3 meters long (6–9 ft). Out of all spinosaurs it most closely resembles "Baryonyx".
Giganotosaurus
"Giganotosaurus" was one of the largest known terrestrial carnivores, but the exact size has been hard to determine due to the incompleteness of the remains found so far. Estimates for the most complete specimen range from a length of , a skull in length, and a weight of . The dentary bone that belonged to a supposedly larger individual has been used to extrapolate a length of . Some researchers have found the animal to be larger than "Tyrannosaurus", which has historically been considered the largest theropod, while others have found them to be roughly equal in size, and the largest size estimates for "Giganotosaurus" exaggerated. The skull was low, with rugose (rough and wrinkled) nasal bones and a ridge-like crest on the lacrimal bone in front of the eye. The front of the lower jaw was flattened, and had a downwards projecting process (or "chin") at the tip. The teeth were compressed sideways and had serrations. The neck was strong and the pectoral girdle proportionally small.
Sinosaurus
The Lufeng Dinosaurian Museum discovered a new specimen of "Sinosaurus" (ZLJT01) in 2007 from the Lufeng Basin. It consists of an incomplete skull and other postcranial fragments. Phylogenetic analysis of this specimen, demonstrates that "Sinosaurus" is a more derived theropod, and is not the most basal dilophosaurid, as held by Smith et al. A cladogram was identified by Christophe Hendrickx and Octávio Mateus. It placed "Sinosaurus" as the sister taxon to "Cryolophosaurus", and together they were the most basal tetanurans.
Liaoningosaurus
The holotype IVPP V12560 (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing) is an articulated skeleton measuring approximately in length. The specimen is unique among all known ankylosaur fossils in the retention of the external mandibular fenestra. Antorbital fenestrae may also be present. It has relatively large teeth, including teeth in the praemaxilla ( primitive or possibly juvenile trait). The points on the tooth crown were unusually long and sharp, giving each tooth a fork-like shape. It had long feet, long lower legs, and long, sharp claws on the hands and feet, unlike the blunt claws of other ankylosaurians. All of these were initially interpreted as juvenile features, given the specimen's small size and lack of fusion between the spine and hip bones. However, information from a second specimen has led some scientists to conclude that the lack of hip fusion and long limbs and toes are in fact adaptations to a semiaquatic lifestyle. The large, fork-like teeth and sharp claws may have been adapted to catch fish and other small animals. Stomach contents recovered with the second "L. paradoxus" specimen show that fish may have formed part of the animal's diet. This indicates that "Liaoningosaurus" could have been either carnivorous or at least omnivorous, making it the first ornithischian thought to have adapted to such a lifestyle, though this is also suspected in more basal ornithischians like heterodontosaurs and now in pachycephalosaurids
Another supposedly unique feature originally identified from the type specimen was the presence of armor plating on the belly. A large segment of what appeared to be the bone from a flat osteoderm covered the underside of the abdomen. This had a surface structure covered with small hexagonal and rhombic bumps. Such plates had never been found with other ankylosaurians, and it has been suggested that, if "L. paradoxus" was indeed semiaquatic, the belly plates may have protected it from predators attacking from below, as in modern turtles. Smaller triangular osteoderms were found on the shoulder, including a small shoulder spike. However, closer examination of the bumps seemed to suggest that they were not sculpted onto a single piece of bone, but instead resembled normal dinosaurian scales. The broken edges of the supposed plates, when studied in 2013 by paleontologist Victoria Arbour and colleagues, did not reveal any internal structure as would be expected from a piece of bone. Arbour and colleagues concluded that the "belly plates" were likely to be pieces of preserved skin.
Hainosaurus
Hainosaurus ("Haino" from the river Haine, where it was first discovered, and "saurus", from Greek sauros, meaning lizard) is an extinct genus of marine lizard belonging to the mosasaur family. It is one of the largest mosasaurs, though its size has been revised more than once. At first it was estimated to be , and the largest mosasaurid. During the 1990s, its size was revised to long; more recently, Johan Lindgren estimated that it reached lengths of up to . It was one of the top marine predators of the Late Cretaceous. Like other giant mosasaurs, this giant predator preyed on turtles, plesiosaurs, pterosaurs, cephalopods, sharks, fish, and smaller mosasaurs.
Pisanosaurus
Based on the known fossil elements from a partial skeleton, "Pisanosaurus" was a small, lightly built dinosauriform approximately in length. Its weight was between . These estimates vary due to the incompleteness of the holotype specimen PVL 2577. The orientation of the pubis is uncertain, with some skeletal reconstructions having it projecting down and forward (the propubic condition) similar to that of the majority of saurischian dinosaurs.
Sinosauropteryx
Ji and Ji (1996) identified many features that set "Sinosauropteryx" apart from other birds and dinosaurs. They found that it was a small primitive bird with a relatively high skull, blunt rostrum and a slightly high premaxilla; that the antorbital fenestra was elliptical but not enlarged, the dentary was robust, the surangular was narrow and elongated, and the dentition is extremely well developed and acute; that there are over 50 extremely elongated caudals, constituting 60% of the body length, and the forelimb is extremely short with a short and thick humerus; the pubis was elongated and extremely inflated at its distal end and the ischium is broad; the hind limb was long and robust, the tibia is only slightly longer than the femur, the tarsals are separated, and the metatarsals are relatively robust with unfused proximal ends; the feathers are short, small, and uniform; many ornament the top of the skull, cervical, and dorsal regions, in addition to the dorsal and ventral caudal region.
Sinotyrannus
Sinotyrannus (meaning "Chinese tyrant") is a genus of large basal proceratosaurid dinosaur, a relative of tyrannosaurids which flourished in North America and Asia during the Jurassic and early Cretaceous periods. "Sinotyrannus" is known from a single incomplete fossil specimen including a partial skull, from the Early Cretaceous Jiufotang Formation of Liaoning, China. Though it is not much younger than primitive tyrannosauroids such as "Dilong", it is similar in size to later forms such as "Tyrannosaurus". It was much larger than contemporary tyrannosauroids; reaching a total estimated length of , it is the largest known theropod from the Jiufotang Formation. The type species is "S. kazuoensis", described by Ji "et al.", in 2009.
Tyrannosauridae
The tyrannosaurids were all large animals, with all species capable of weighing at least 1 metric ton. A single specimen of "Alioramus" of an individual estimated at between long has been discovered, although it is considered by some experts to be a juvenile. "Albertosaurus", "Gorgosaurus" and "Daspletosaurus" all measured between long, while "Tarbosaurus" reached lengths of from snout to tail. The massive "Tyrannosaurus" reached in the largest specimen, FMNH PR2081.
Sinosaurus
Sinosaurus (meaning "Chinese lizard") was a tetanuran theropod dinosaur which lived during the Early Jurassic Period. It was a bipedal carnivore approximately in length. Fossils of the animal were found at the Lufeng Formation, in the Yunnan Province of China.
Tylosaurus
Along with plesiosaurs, sharks, fish, and other mosasaurs, "Tylosaurus" was a dominant predator of the Western Interior Seaway during the Late Cretaceous. The genus was among the largest of the mosasaurs (along with "Mosasaurus hoffmannii"), with the possibly conspecific "Hainosaurus bernardi" reaching lengths up to , and "T. pembinensis" reaching comparable sizes. "T. proriger", the largest species of "Tylosaurus", reached lengths of about .
Sinocalliopteryx
The well-preserved skeleton of the "Sinocalliopteryx" holotype contained the partial leg of a dromaeosaurid within the abdominal cavity, comprising a complete lower leg and foot with toes and claws in their natural, articulated position. While the leg part, about one foot long, is very large in relation to the abdominal cavity, it is clearly situated within it, lying between the ribs. Ji and colleagues in 2007 suggested that this could indicate it preyed upon the smaller, bird-like dinosaur. This discovery indicated that "Sinocalliopteryx" may have been an agile, active, "fierce" predator, especially since other compsognathids have been found with (presumably fast-moving) lizards and small mammals in their abdominal cavities. In 2012 the dromaeosaurid was tentatively identified as an individual of "Sinornithosaurus" with a length of 1.2 metres (3.9 ft). The 2012 study also reported newly discovered remains of prey animals. Above the dromaeosaurid leg, feathers are visible. Below it two clusters of digested food can be seen. It was suggested that the feathers had belonged to a bird and were with the leg still present in the stomach. The digested food would, using the preserved digestive tract of "Scipionyx" as a reference, have been positioned in the duodenum. The C-shaped abdominal contents of this specimen appear to reflect of the original contour of the digestive tract.
Goronyosaurus
"Goronyosaurus" is a smaller mosasaur, with a body length reconstructed as by Soliar (1988). Previously the body had been estimated at , although Soliar identified that this length was based on a false head: body ratio. This ratio is 9.1:100 is drastically different from the ratio in tylosaurines, where the head is 13.8% the length of the body.