This page is only to provide real-life facts about the dinosaurs you play as in-game. If you wish to view in-game stats or appearances, go onto the dinosaur's or other creature's page. These dinosaurs here are categorized under different types below:
Tyrannosaurus rex (meaning: tyrant/lizard king) lived during the late Maastrichtian stage of the Cretaceous period (specifically 68-66 million years ago) in North America. This genus of tyrannosaurid, despite proboscidean-sized, was seemingly agiler and might've been capable of reaching speeds of up to 37 mph. Tyrannosaurus was one of the largest land carnivores of all time, rivaled only by Spinosaurus and several carcharodontosaurs, including Mapusaurus, Tyrannotitan and Carcharodontosaurus. Recent studies show that the estimated mass of this genus ranged from 7.3-8.8 tonnes. Tyrannosaurus was also found to have extremely good eyesight (comparable to that of an eagle's) and had possibly the most powerful bite of any organism (estimated to be between 8000 and 12,800 pounds). The creature itself is most likely covered in scales, as given by the recently found integument from itself, from closely related Tyrannosaurids such as Albertosaurus and Tarbosaurus, which are closer to Tyrannosaurus than is Yutyrannus to Tyrannosaurus.
Triceratops horridus (aka the Trike) was a Ceratopsian that lived in the same time and place as Tyrannosaurus. The Triceratops sported a large solid frill around its head as well as two large brow horns and one small nose horn. It looked similar to the current day Rhinoceros and perhaps behaved in a vaguely similar fashion. The Function of the frill and horns is unknown but scientists speculate it was could have been used as self-defense from predators such as the T.rex, for courtship, identifying their own kind, or for fighting other trikes over mates like how deer use their antlers. The Trike moved on 4 legs with hoof-like feet like most other herbivores in the Late Cretaceous. Triceratops, unlike most herbivores of its time, was not that social; they often only lived in small groups or alone. It's not known why but it's most likely because the environment they lived in did not allow them to travel in herds of hundreds like the Centrosaurinae. Like the Black Rhinoceros, the Triceratops most likely ate bushes and low-hanging branches.
Ornithomimus velox is a type of Ornithomimid that lived in the Late Cretaceous(specifically 76-66 million years ago) in North America. Ornithomimids were swift, bipedal theropods with small toothless beaks that indicate an omnivorous diet. A fossil was discovered in 2016 that revealed that Ornithomimus(and probably Ornithomimids in general) had feathers; the specimen had a coat of fuzz over most of its body and wing covering its arms. An interesting feature of Ornithomimus is that it had scaleless skin covering the leg from the knee down that resembled an ostrich, indicating they had a similar lifestyle.
Styracosaurus albertensis was a Ceratopsian that lived in North America about 75 million years ago. It had four to six long horns extending from its neck frill, a smaller horn on each of its cheeks, and a single horn protruding from its nose, which may have been up to 60 centimeters (2.0 feet) long and 15 centimeters (5.9 inches) wide. The function or functions of the horns and frills have been debated for many years.
Styracosaurus was a relatively large dinosaur, reaching lengths of 5.5 meters (18 feet) and weighing nearly 3 tonnes. It stood about 1.8 meters (5.9 feet) tall. Styracosaurus possessed four short legs and a bulky body. Its tail was rather short. The skull had a beak and shearing cheek teeth arranged in continuous dental batteries, suggesting that the animal sliced up plants. Like other centrosaurines, this dinosaur may have been a herd animal, traveling in large groups, as suggested by bonebeds.
Euoplocephalus tutus is one of the largest of all the Ankylosaurs, living in North America from 76 to 75 million years ago.The first fossil of Euoplocephalus was found in 1897 in Alberta, in the Dominion of Canada. In 1902, it was named Stereocephalus, but that name had already been given to an insect, so it was changed in 1910. Later, many more ankylosaurid remains were found from the Campanian of North America and often made separate genera. In 1971, Walter Coombs concluded that they all belonged to Euoplocephalus which then would be one of the best-known dinosaurs. Recently, however, experts have come to the opposite conclusion, limiting the authentic finds of Euoplocephalus to about a dozen specimens. These include a number of almost complete skeletons, so much is nevertheless known about the build of the animal.
Euoplocephalus was about five to six meters long and weighed over two tons. Its body was low-slung and very flat and wide, standing on four sturdy legs. Its head had a short drooping snout with a horny beak to bite off plants that were digested in the large gut. Like other ankylosaurids, Euoplocephalus was largely covered by bony armor plates, among them rows of large high-ridged oval scutes. The neck was protected by two bone rings. It could also actively defend itself against predators like Gorgosaurus using a heavy club-like tail end.
Brachiosaurus altithorax was a Brachiosaurid Sauropod that lived in North America during the Late Jurassic(specifically from 154 to 153 million years ago). It was first described by Elmer S. Riggs in 1903 from fossils found in the Grand River Canyon (now Colorado River) of western Colorado, in the United States. Riggs named the dinosaur Brachiosaurus altithorax, declaring it "the largest known dinosaur". Brachiosaurus had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. However, the proportions of Brachiosaurus are unlike most sauropods: the forelimbs were longer than the hindlimbs, which resulted in a steeply inclined trunk, and its tail was shorter in proportion to its neck than other sauropods of the Jurassic.
Brachiosaurus is the namesake genus of the family Brachiosauridae, which includes a handful of other similar sauropods. Much of what is known by laypeople about Brachiosaurus is in fact based on Giraffatitan brancai, a species of brachiosaurid from the Tendaguru Formation of Tanzania that was originally described by German paleontologist Werner Janensch as a species of Brachiosaurus.
Allosaurus fragilis is a Carnosaur that lived in North America from 155 to 150 million years ago. Despite being often called "The lion of the Jurassic", Allosaurus actually had a weak bite force, it being weaker than the bite force of a lion. The main hunting strategy of Allosaurus is to 'hug' big game like sauropods, grappling them with its arm while slashing their flanks with their serrated teeth which cause severe blood loss.
Baryonyx walkeri is a Spinosaurid that lived in Europe from 130 to 125 million years ago. The holotype specimen was discovered in 1983 in Surrey, England, and the animal was named B. walkeri in 1986. The genus name, Baryonyx, means "heavy claw" and alludes to the animal's very large claw on the first finger; the specific name (walkeri) refers to its discoverer, amateur fossil hunter William J. Walker. Fragmentary specimens were later discovered in other parts of the United Kingdom and Iberia. The holotype specimen is one of the most complete theropod skeletons from the UK, and its discovery attracted media attention.
Baryonyx was between 7.5 and 10 m (25 and 33 ft) long and weighed between 1.2 and 1.7 t (1.3 and 1.9 short tons), but the holotype specimen may not have been fully grown.
Spinosaurus aegyptiacus(meaning "spine lizard") is the largest Spinosaurid to have ever lived; it also is one of the largest "land" carnivores, rivaling Tyrannosaurus and some of the members of the Giganotosaurini. Spinosaurus lived in what now is North Africa, during the Late Cretaceous period(specifically 112 to 93.5 million years ago). This genus was known first from Egyptian remains discovered in 1912 and described by German paleontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in recent years. It is unclear whether one or two species are represented in the fossils reported in the scientific literature.
Spinosaurus was one of several predators of its environment, many of which are giants of their kind. Spinosaurus avoided competition with the other theropods it lived with by exploiting a niche few other non-avian dinosaurs have experimented with. The rivers that ran through their habitat was full of fish that were the largest of their kind; the largest sawfish(Onchopristis), the largest bichirs(Bawitius), the largest coelacanths(Mawsonia) and the largest lungfish(Ceratodus) lived in this ecosystem; these giant fish provided a bounty for those that could reach it like Spinosaurus. This reason is probably why Spinosaurus lasted so long, outliving most of the other giants that it once shared its habitat with; and it only died out when the rivers were flooded by rising sea levels and the giant fish it depended upon went extinct.
Avimimus portentosus is a small basal Caenagnathid(a kind of Oviraptorosaur) that lived in Asia 70 million years ago.Meaning "bird mimic" (Latin avis = bird + mimus = mimic),named for its bird-like characteristics.The skull was small compared to the body, though the brain and eyes were large. The size of the bones which surrounded the brain and were dedicated to protecting it are large. This is also consistent with the hypothesis that Avimimus had a proportionally large brain.
The jaws of Avimimus were thought to form a parrot-like beak lacking teeth, and a thorough review of the holotype specimen's anatomy confirmed that no teeth were preserved, although a series of tooth-like projections along the tip of the premaxilla were present. However, subsequently discovered specimens have been reported to preserve small premaxillary teeth. The small teeth or possible lack thereof in Avimimus suggests that it may have been an herbivore or omnivore. Kurzanov himself, however, believed that Avimimus was an insectivore.
Troodon formosus is a Troodontid that lived in North America from 77 to 76 million years ago. Troodon has been thought of to have night vision due to its enormous eyes. Discovered in October 1855, T. formosus was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877. Several well-known troodontid specimens from the Dinosaur Park Formation in Alberta were once believed to be members of this genus. However, recent analyses in 2017 have found the genus to be undiagnostic and referred some of these specimens to the genus Stenonychosaurus (long believed to be synonymous with Troodon) and others to the newly created genus Latenivenatrix.
Gigantoraptor erlianensis is one of the largest Caenagnathids to ever live; it lived 85 million years ago in Asia. When it was described, it was clear that Gigantoraptor belonged to the Oviraptorosauria, a group named after Oviraptor; Gigantoraptor, however, was a giant compared to its relatives. It was approximately three times as long and 35 times more massive than the heaviest earlier discovered oviraptorosaurid Citipati. Xu et al. estimated the length at 8 meters (26 ft) and the weight at 1400 kilograms. In 2010, Gregory S. Paul even gave an estimate of two tonnes (2.2 tons).
The toothless lower jaws of Gigantoraptor are fused into a broad shovel-like mandible. They indicate that the unknown skull was over half a meter long and toothless also, probably equipped with a horny beak. The front tail vertebrae have very long neural spines and are heavily pneumatized with deep pleurocoels. The middle section of the relatively short tail is somewhat stiffened by long prezygapophyses.
Pliosaurus funkei (meaning "more lizard") is an thalassophonean pliosaurid known from the Late Jurassic(specifically 155 to 147 million years ago) in Europe and South America. Their diet would have included fish, cephalopods, and other marine reptiles. Pliosaurus funkei is often referred to as "Predator X", which it was called before it was officially described. Its appearance in the documentary Planet Dinosaur results in it probably being the most famous species in its genus.
Mosasaurus hoffmannii(meaning "lizard of the muse river") is a mosasaur that lived in Europe and North America during the Late Cretaceous(specifically 70 to 66 million years ago). The Mosasaurus was one of the last and largest mosasaurs. The largest Mosasaurus fossils found was nearly 13 meters in length The Mosasaurus had long barrel-shaped bodies with 4 flippers (2 large on the front and 2 smaller on the back.), a tail with a fluke like that of modern-day sharks, and a robust skull with the lower jaw being attached tightly to the skull. Scientists predict that the Mosasaurus lived near the ocean surface and its diet might've consisted of fish, turtles, smaller mosasaurs, pterosaurs, and plesiosaurs.
Elasmosaurus platyurusis is a piscivorous Elasmosaurid plesiosaur that lived in North America during the Late Cretaceous(specifically 80 million years ago). Elasmosaurus was 10.3 meters (34 ft) long, and would have had a streamlined body with paddle-like limbs, a short tail, a small head, and an extremely long neck.
Ichthyosaurus communis is a Ichthyosaur that lived in Europe for the Late Triassic to the Early Jurassic. Ichthyosaurus is among the best known ichthyosaur genera, with the order Ichthyosauria being named after it. As an ocean-going hunter, the main diet of Ichthyosaurus would have been primarily if not exclusively piscivorous. Study of coprolites has confirmed the presence of both fish and squid in its feeding habits. Although Ichthyosaurus appears to have relied upon its sight for feeding, the solid bone structure of the eardrums suggests that they could have 'heard' their prey from a distance by their vibrations in the water. Some specimens have shown smaller Ichthyosaurus remains inside larger ones in positions that appear to be within a uterus of a parent animal and some even appear to have been in the process of being born. This means that Ichthyosaurus almost certainly did not lay eggs, but was instead viviparous, giving birth to live young. As with other viviparous air-breathing marine organisms, the young emerged from the mother tail first so that they did not drown while being born.
Liopleurodon ferox is a Pliosaur in the family known as the pliosauridae that lived in Europe during the Middle Jurassic period(specifically 160 to 155 mya).
The name "Liopleurodon" (meaning "smooth-sided tooth") derives from Ancient Greek words: λεῖος [leios], "smooth"; pleurá, side or rib; and odṓn, tooth. The genus name Liopleurodon was coined by Henri Émile Sauvage in 1873 on the basis of very poor remains consisting of three 70 millimeter (2¾ inch) teeth.
Despite being depicted as being 80 feet long in the Walking With Dinosaurs series, Liopleurodon was actually much smaller, being estimated to have grown up to 6.39 meters (21.0 ft) in length. Other Pliosaurs like Pliosaurus itself and Kronosaurus growing to lengths much larger than Liopleurodon.
Shastasaurus pacificus("Mt. Shasta lizard") is an merriamosauria ichthyosaur located in the shastasauridae. Shastasaurus lived in North America and Asia during the Middle and Late Triassic period(specifically 235 to 205 million years ago). Shastasaurus is the largest marine reptile that has yet been found. Shastasaurus was highly specialized, and differed considerably from other ichthyosaurs. It was very slender in profile. The largest specimens had a ribcage slightly less than 2 meters (6.6 ft) deep despite a distance of over 7 meters (23 ft) between its flippers. There are two other possible species that belong in the genus but they could also belong to different genera. The adults and juveniles lacked teeth whatsoever, implying they may have been suction feeders; they probably preyed on schools of small fish and cephalopods.
Ectenosaurus clidastoides is a plioplatecarpine mosasaur that lived in North America during the Late Cretaceous(specifically 85 to 84 million years ago). The Plioplatecarpines included genera such as Platecarpus and Selmasaurus and lived from 89 million years to 66 million years ago.
The generic name means "Drawn-out lizard", from Greek ectenes ("drawn-out") and Greek sauros ("lizard") referencing the elongated muzzle. Based on the size of the preserved skull, about 74 centimeters in length;Ectenosaurus would have reached sizes of 5.7 meters in length. It was a rare genus of mosasaur with several unique characteristics that clearly separate it from other mosasaur genera. The most prominent of these features is its elongated jaws, elongated in a similar vein to other mosasaurs with elongated jaws, such as Plotosaurus and Pluridens.
Thalassomedon haningtoni is a elasmosaurid plesiosaur that lived in North America during the Late Cretaceous(specifically 95 million years ago). Thalassomedon was named by Welles in 1943. Thalassomedon is among the largest of the elasmosaurids, with a total length of 10.86 meters (35.6 ft) for the holotype. There is a larger skull, however, suggesting a much larger animal, potentially up to 11.7 meters (38 ft). The neck is also very long; it comprises 62 vertebrae and is about 5.9 meters (19 ft) - over half of the total length. The skull is 47 centimeters (19 in) long, with 5 centimeters (2.0 in) long teeth. The flippers were about 1.5–2 meters (4.9–6.6 ft) long. Stones have been found in its stomach area leading some to theorize that they were used for ballast or digestion. If the latter, stomach action would cause the stones to help grind ingested food.
Archelon ischyros is a chelonioid testudine in the family Protostegidae that lived in North America during the Late Cretaceous(specifically 80 million years ago). Archelon is the largest of all the sea turtles that are known; it is also the second-heaviest turtle know to exist, only a little bit behind Stupendemys. The first specimen of Archelon (YPM 3000) was collected from South Dakota by Dr. G.R. Wieland in 1895 and described by him the following year (Wieland, 1896). The largest Archelon fossil, found in the Pierre Shale of South Dakota in the 1970s, measures more than 4 meters (13 ft) long, and about 5 meters (16 ft) wide from flipper to flipper. It was a marine turtle, whose closest living relative in the present day is the Leatherback sea turtle(Dermochelys coriacea). A feature it shares with its living relative is the non-fused shell plates which are fused together in other sea turtles; Archelon instead having the plates being covered by fat and thick skin.
Prognathodon solvayi is a mosasaur located in the Mosasaurinae that lived in North America, Africa, Asia, Europe, and New Zealand during the Late Cretaceous(specifically 83 to 66 million years ago). Six different species of Prognathodon are known with another possible six also existing. Prognathodon constitutes one of the largest-bodied mosasaur genera, with the largest known skull (belonging to P. currii) exceeding 140 cm in length. Despite its massive size, remains of the genus are often fragmentary and incomplete. To date, very few specimens are known with articulated skulls and none with an entire skeleton. Though many species were large with sizes approaching or potentially exceeding 10 meters, such as P. currii, P. saturator and P. overtoni, many species were considerably smaller in size. The type species, P. solvayi, was the smallest, barely reaching 5 meters in length.
Kronosaurus queenslandicus is a brachauchenine pliosaur that lived in Australia and South America during the Early Cretaceous(specifically from 125 to 99 million years ago). With an estimated length of 9–10.5 meters (30–34 ft), it was among the largest pliosaurs, and is named after the leader of the Greek Titans, Cronus. Like other pliosaurs, Kronosaurus was a marine reptile. It had an elongated head, a short neck, a stiff body propelled by four flippers, and a relatively short tail. The posterior flippers were larger than the anterior. Kronosaurus was carnivorous, and had many long, sharp, conical teeth that were robust; the conical teeth and the large head for its body size suggest that it probably hunted marine reptiles like its plesiosaur cousins often.
Fresnosaurus drescheri is a elasmosaurid plesiosaur from North America during the Late Cretaceous(specifically from 70 to 66 million years ago). Fresnosaurus was first described by Welles in 1943. The generic name Fresnosaurus honors Fresno County, while the specific name honors Arthur Drescher. Fresnosaurus was probably at least 30 feet in length, although there are estimates that it could have reached about 40 feet since the fossil wasn't fully grown. Like all elasmosaurid plesiosaurs, it probably ate small bony fish, belemnites, and ammonites while being preyed upon by the mosasaurs it lived with like Plotosaurus.
The West Indian Ocean coelacanth(Latimeria chalumnae) is only of two species in the genus Latimeria, which is the last genus in a very ancient family. The West Indian Ocean coelacanth is found primarily near the Comoro Islands off the east coast of Africa. They follow the oldest known living lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish, reptiles, birds, and mammals than to the common ray-finned fishes. Thanks to overfishing and their slow growth rate, the West Indian Ocean Coelacanth is a critically endangered species.
Coelacanths belong to the subclass Actinistia, a group of lobed-finned fish related to lungfish and certain extinct Devonian fish such as osteolepiforms, porolepiforms, rhizodonts, and Panderichthys. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa.
The coelacanth was long considered a "living fossil" because it was believed to be the sole remaining member of a taxon otherwise known only from fossils, with no close relations alive, and to have evolved into roughly its current form approximately 400 million years ago. However, several recent studies have shown that coelacanth body shapes are much more diverse than previously thought. The term "stabilomorph" has begun to replace the term "living fossil" to describe these animals.
Cretoxyrhina mantelli was a lamniform shark of the Cretoxyrhinidae that lived in North America during the Late Cretaceous(specifically from 100 to 82 million years ago). It had no common name in the early literature, it gained the nickname of "the Ginsu shark" in reference to the Ginsu knife since it fed by slicing into its victims with its knife-sharp teeth. Cretoxyrhina is among the most well-understood fossil sharks to date. Several preserved specimens have revealed a great deal of insight about the physical features and lifestyle of this ancient predatory shark.
Cretoxyrhina grew up to 9 meters (30 ft) long, and exceeded the extant great white shark(Carcharodon carcharias) in size. The jaws of Cretoxyrhina contained up to seven rows of teeth, with 34 teeth in each row of its upper jaw and 36 in each row of its lower jaw. Each of these teeth was up to 7 centimeters (3 in) long, curved, and smooth-edged, with a thick enamel coating. The jaws and teeth allow it to rip apart carcasses efficiently as well as kill the large fish and small marine reptiles it preyed on.
Leedsichthys problematicus is a giant member of the Pachycormidae, an extinct group of Mesozoic ray-finned fishes that lived in Europe and South America during the Middle Jurassic period.
The first remains of Leedsichthys were identified in the nineteenth century. Especially important were the finds by the British collector Alfred Nicholson Leeds, after whom the genus was named "Leeds' fish" in 1889. As the vertebrae are among the parts that have not been preserved, it is hard to determine the total body length. Estimates have varied wildly. At the beginning of the twentieth century a length of nine meters (thirty feet) was seen as plausible, but by its end Leedsichthys was sometimes claimed to have been over thirty meters (hundred feet) long. Recent research has lowered this to about sixteen meters (fifty feet) for the largest individuals.
Megalodon is an extinct genus of bivalve Mollusks that reportedly lived from the Devonian to the Jurassic Period in Europe, North America, Asia, South America, and Africa. It is not clear, however, that all the fossils assigned to Megalodon from that span of time really belong in the same genus. Megalodon and it's relatives such as Pachyrisma grande were shown to be closely related to the extinct rudists and the living Cockles and Venus clams.
Helicoprion bessonowi is a shark-like eugeneodontid holocephalid that lived in North America, Europe, Asia, and Australia during the Permian the early parts of the Triassic. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls"— the cartilaginous skull, spine, and other structural elements have not been preserved in the fossil record, leaving scientists to make educated guesses as to its anatomy and behavior. For a while the position of the tooth whorls was unknown until the jaw of one its relatives was found; the teeth being found somewhere in the lower jaw. After the find, studies revealed it was probably placed at the back of the jaw in the throat. The closest living relatives of Helicoprion (and other eugeneodontids) are the chimeras which are also known as ratfish.
Tusoteuthis longa was a large squid native to North America during the Campanian stage of the Cretaceous. Tusoteuthis hunted large fish and the occasional small marine reptile while being preyed on by large marine reptiles like Tylosaurus proriger. The Tusoteuthis was an unusually large Cephalopod, being an alike size to the Architeuthis(Giant Squid) in the modern world. Recent studies, however, suggest that it was much more closely related to Vampire Squids (Vampyroteuthis infernalis).
Onchopristis numidus is a giant sclerorhynchid sawfish that lived in North America, Africa, and New Zealand from the Early to Late Cretaceous. It had an elongated snout lined laterally with barbed teeth. As with modern sawfish, Onchopristis' eyes were on top of its head, to spot predators rather than prey, and its mouth and gills were under its body. The rostrum, or snout, was around 2.5 meters (8.2 ft) long and the whole animal is estimated to be about 8 meters (26.2 feet) long.
These fish used their rostrum as a way to detect prey, sweeping their rostrum from side to side to put their sensors to use. Once they detected prey, they would then chop it to pieces with the barbs on its rostrum. Despite being a large predator, it was preyed on by larger carnivores like Spinosaurus.
Squalicorax falcatus is a lamniform shark of the Anacoracidae known to have lived in North America, Europe, and Africa during the Late Cretaceous period. These sharks are of medium size, up to 5 m (usually around 2 m) in length. Their bodies were similar to the modern gray sharks, but the shape of the teeth is strikingly similar to that of a tiger shark. The teeth are numerous, relatively small, with a curved crown and serrated, up to 2.5 – 3 cm in height (the only representative of the Mesozoic Lamniformes with serrated teeth). Large numbers of fossil teeth have been found in Europe, North Africa, and North America.
Squalicorax was a coastal predator, but also scavenged as evidenced by a Squalicorax tooth found embedded in the metatarsal (foot) bone of a terrestrial hadrosaurid dinosaur that most likely died on land and ended up in the water. Other food sources included turtles, mosasaurs, the relative of Xiphactinus known as Ichthyodectes, and other bony fishes and sea creatures.
Megalodon (Carcharocles megalodon), meaning "big tooth", is an extinct species of shark that lived approximately 23 to 2.6 million years ago (mya), during the Early Miocene to the end of the Pliocene. It was formerly thought to be a member of the Lamnidae family, making it closely related to the great white shark (Carcharodon carcharias). However presently there is near unanimous consensus that it belongs to the extinct family Otodontidae, which diverged from the ancestry of the great white shark during the Early Cretaceous. Its genus placement is still debated, authors placing it in either Carcharocles, Megaselachus, Otodus, or Procarcharodon.
Scientists suggest that megalodon looked like a stockier version of the great white shark, though it may have looked similar to the basking shark (Cetorhinus maximus) or the sand tiger shark (Carcharias taurus). Regarded as one of the largest and most powerful predators to have ever lived, fossil remains of megalodon suggest that this giant shark reached a maximum length of 18 meters (59 ft) with the average size being 10.5 meters (34 ft). Their large jaws could exert a bite force of up to 110,000 to 180,000 newtons (25,000 to 40,000 lbf). Their teeth were thick and robust, built for grabbing prey and breaking bone.
Megalodon probably had a major impact on the structure of marine communities. The fossil record indicates that it had a cosmopolitan distribution. It probably targeted large prey, such as whales, seals, and sea turtles. Juveniles inhabited warm coastal waters and fed on fish and small whales. Unlike the great white, which attacks prey from the soft underside, megalodon probably used its strong jaws to break through the chest cavity and puncture the heart and lungs of its prey.
Theropods are often dinosaurs with hallow bones and 3 tipped toes. They usually resemble modern-day birds.
Balaur bondoc is a small maniraptoran that lived during the Late Cretaceous Period in what is now Romania. The name of this small animal means "Stocky dragon" and it was named after a dragon of Romanian folklore, the Balaur. The current placement of this animal on the evolutionary line of dinosaurs is unknown, some people think it was an herbivorous bird, others think that it might have been a Dromeosaurid of some kind. This animal was subjected to a phenomenon that is known as insular gigantism, due to the lack of some predators and plenty of food after millions of years of evolution it mostly gave up the ability to fly, only being able to glide. Many other animals on its island also became either large or small, things like Magyarasaurus(a Titanosaur) and Zalmoxes(an Iguanodontid) became smaller though titans like Hatzegopteryx, a gigantic Azhdarchid pterosaur still preyed on these dwarfs. This animal might have been a small herbivore searching for seeds in the bushes and swamps that it inhabited. The animal is only known from one specimen which is called EME.VP 313. The fossil has a hand, a couple of vertebrae and ribs, a pelvic bone and two legs and feet that, surprisingly, possess two "killing claws" or talons.
Gallimimus bullatus (aka the Galli) was a Ornithomimid that lived in Asia during the Late Cretaceous period(specifically 70 million years ago). Its name means Chicken mimic, although it being much larger than a chicken and was rather an ostrich-like. The Gallimimus had a small head, toothless beak, a long neck, 2 short arms, 2 long legs, a long tail, and hollow bones. The tail was likely used for balance as based on the size of its legs it most likely ran at high speeds. The Galli had its eyes on the sides of its head, so it didn't possess binocular vision. It's unknown what the Galli ate. Scientists have debated that it may have eaten small animals, but due to its rake like arms, it could've eaten roots in the soil. It could've possibly been an omnivore. Another topic of debate was if the Galli had feathers. Some recent fossils have been found in its close relatives that suggest it may have had a coat of feathers along its neck and back down through its tail and arms with the feathers stopping at the knee.
Achillobator giganticus was a large dromaeosaur reaching a length of 20 feet. Achillobator lived during the Late Cretaceous(specifically 98-83 million years ago) in Asia. It had a name derived from the name of the Greek hero Achilles and the Mongolian word for hero. Achillobator could of preyed on a number of species including: Garudimimus, Avimimus, Enigmosaurus, Gilmoreosaurus, Heishansaurus, Bactrosaurus, and Graciliceratopswhich lived in the same time and place as Achillobator. The Achillobator was discovered in 1989, but was not formally named and described until 1999.Achillobators hip was pointing in the opposite direction of other dromaeosaurs, along with this, the skull of Achillobator was similar in proportions to a carnosaur skull when compared to the body, its neck was short and robust, and proportionally weird legs for a dromaeosaur, these features are some of the features that make Achillobator a distinct genus.
Ceratosaurus nasicornis was a medium sized ceratosaur that was part of the ceratosauridae; living in North America, Europe and possibly Africa during the Late Jurassic(specifically from 156 to 145 million years ago). What makes the Ceratosaurus and its relatives unique among its similar-sized brethren is the horns on their nose, being one of the only theropods to have this particular trait. Ceratosaurus teeth were thin and blade-like, designed to slice through flesh. While its head was a viable weapon, its arms were not; The arms of Ceratosaurus were more comparable to a Tyranosaurs in size compared to the body, with four short, stubby fingers. In North America and Europe, Ceratosaurus lived with the other two large carnivores of its time, Allosaurus and Torvosaurus. The reason it can coexist with these larger carnivores was that it filled a different ecological role, preying on smaller herbivores as well as scavenging more often then Allosaurus and Torvosaurus. It has been theorized that Ceratosaurus hunted aquatic prey more often than it did terrestrial, with a more crocodile-like vertebrae structure and other features pointing to this.
Guanlong wucaii is a proceratosaurid tyrannosauroid that lived in Asia during the Late Jurassic(specifically 160 million years ago). The taxon was first described in 2006 by Xu et al., who found it to represent a new taxon related to Tyrannosaurus. The name is derived from Chinese, translating as "five colored crowned dragon". Two individuals are currently known, a partially complete adult and a nearly complete juvenile. At about 3 meters long (9.8 ft), these small predators lived 92 million years before its well-known relative Tyrannosaurus. A striking feature on the animals is the large crest on their head. Unlike most later tyrannosaurs, Guanlong had three long fingers on its hands. Aside from its distinctive crest, it would have resembled its more basal relative Dilong, and like Dilong probably had a coat of primitive feathers.
Irritator challengeriis is a spinosaurid that lived in South America during the Early Cretaceous(specifically 110 million years ago). Current estimates of its size indicate a length of 8 meters (26 feet). In 2010, Gregory S. Paul gave lower estimations of 7.5 meters and one tonne. Despite appearances, Irritator was closer related to Spinosaurus than it is to Baryonyx.
So far the only fossil that has been found was an 80-centimeter long fossil skull in the Romualdo Member, a layer member of the Santana Formation. This skull strongly resembles the skulls of Suchomimus and Spinosaurus. The genus is often regarded today as identical (synonymous) with Angaturama, which lived in the same time and the same place as Irritator.
Fossilized spinosaurid teeth found at around the same time and place were found lodged in the neck of a pterosaur, the tooth probably came from an Irritator or a spinosaurid similar to Irritator. This evidence suggests that Irritator may have preyed on pterosaurs as well as on fish.
Utahraptor ostrommaysorum (meaning "Utah's predator") is the largest known member of the Dromaeosaurids. Utahraptor lived in North America during the Early Cretaceous(specifically 126 million years ago). The holotype specimen of Utahraptor is fragmentary, consisting of skull fragments, a tibia, claws and some caudal (tail) vertebrae. These few elements suggest an animal about twice the length of Deinonychus. Like other dromaeosaurids, Utahraptor had large curved claws on their second toes. One claw specimen is preserved at 22 centimeters (8.7 in) in length and is thought to reach 24 cm (9.4 in) restored.
Concavenator corcovatus was a 20 foot long Carcharodontosaurid Carnosaur that lived in Europe during the Early Cretaceous(specifically 130 million years ago). Concavenator is unique among its relatives because of the distinctive spine on its back which was probably used for display, or supported a hump, or may have even aided in swimming as a sail. Along with this, Concavenator possessed knobs on its forelimb, which could be feathers; if the knobs are feathers, then Concavenator would be the first Carcharodontosaurid with evidence of feathers. Possible prey of the Concavenator included the sauropod Aragosaurus, mainly different species of Iguanodont, the stegosaur Craterosaurus, and Hypsilophodontids Hylaeosaurus, Stenopelix, and Valdosaurus. Pelecanimimus, an ornithomimid, may have also been on Concavenator's menu.
Dilophosaurus wetherilli is a dilophosaurid that lived in North America during the Early Jurassic(specifically 193 million years ago). Dilophosaurus was among the largest carnivores of its time and had is very distinct for its pair of rounded crests on its skull. Dilophosaurus measured about 7 meters (23 ft) long and weighed about 400 kilograms (880 lb). Studies on the jaws of the Dilophosaurus suggest that it may have preferred to fish rather than hunt the sauropodomorphs that it coexisted with.
A study by Robert J. Gay (2005) comparing various specimens found no indication that sexual dimorphism was present in Dilophosaurus, so males and females would have been largely the same in terms of skeletal anatomy.
Coelophysis bauri is a coelophysid that lived in North America during the Late Triassic to Early Jurassic(specifically from 203 to 196 million years ago). Coelophysis has a second species that lived in Africa known as Coelophysis rhodesiensis.
Coelophysis was a small, slenderly-built, ground-dwelling, bipedal carnivore, that could grow up to 3 m (9.8 ft) long. Coelophysis is one of the earliest known dinosaur genera. Scattered material representing similar animals has been found worldwide in some Late Triassic and Early Jurassic formations.
Murusraptor barrosaensis was a megarptorian that lived in South America during the Late Cretaceous(specifically from 93 to 89 million years ago). While the currently we only have the bones of a 21 ft juvenile, it is unknown how large Murusraptor actually could have grown to. Possible prey included the ceratopsian Notoceratops and Saltosaurus, and was possibly competed with the Carnotaurus, or maybe preyed upon it if it grew big enough. Murusraptor, like its cousin Megaraptor, had a large claw on its forelimbs.
Gojirasaurus quayi (meaning "Godzilla Lizard") is a possibly dubious coelophysoid that lived in North America during the Late Triassic(specifically 210 million years ago). Gojirasaurus was named after the giant monster movie character Gojira (the Japanese name for Godzilla). Gojirasaurus is one of the largest of the coelophysoids, as well as one of the largest known theropods from the Triassic Period, being estimated to be about 18 feet long. The size of its tibia was 469 mm, which was comparable to that of Liliensternus (409 mm) and Dilophosaurus (555 mm). Gojirasaurus shared it's habitat with non-dinosaurian archosaurs like Desmatosuchus and Postosuchus as well as other theropods like the herrerasaurid Chindesaurus.
Carnotaurus sastrei is a Abelisaurid Ceratosaur that lived in South America during the Late Cretaceous period(specifically from 72 to 69 million years ago). Known from a single well-preserved skeleton, it is one of the best-understood theropods from the Southern Hemisphere. This predator was like a cheetah. Using its speed, it sprinted and ran down its prey. It is believed that Carnotaurus is one of the fastest large carnivorous dinosaurs to have ever lived.
The distinctive horns and the muscular neck may have been used in fighting conspecifics. According to separate studies, rivaling individuals may have combated each other with quick head blows, by slow pushes with the upper sides of their skulls, or by ramming each other head-on, using their horns as shock absorbers. The feeding habits of Carnotaurus remain unclear: some studies suggest the animal was able to hunt down very large prey such as sauropods, while other studies find it preyed mainly on relatively small animals. It has recently been discovered that Carnotaurus could swallow prey up to the size of a human whole, with a pouch like that of a pelican. Carnotaurus's skull was short and deep for a predator.
Ichthyovenator laosensis is a spinosaurid that lived in Asia during the Early Cretaceous. The generic name is derived from Greek ἰχθύς (ichthys), "fish", and Latin venator, "hunter", in reference to a piscivorous lifestyle. Ichthyovenator is distinct from other spinosaurids in that it had "two sails" on its back shown in the vertebrae, but this may have been covered over by skin and flesh in life. Ichthyovenator is one of the best preserved and well known of the Asian spinosaurids.
Albertosaurus sarcophagus is a genus of albertosaurine tyrannosaurid that lived in North America during the Late Cretaceous Period (specifically from 71-68 million years ago). Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species.
As a tyrannosaurid, Albertosaurus was a bipedal predator with tiny, two-fingered hands and a massive head that had dozens of large, sharp teeth. It may have been at the top of the food chain in its local ecosystem. While Albertosaurus was large for a theropod, it was much smaller than its larger and more famous relative Tyrannosaurus rex, growing nine to ten meters long and weighing less than possibly 2 metric tons.
Since the first discovery in 1884, fossils of more than 30 individuals have been recovered, providing scientists with a more detailed knowledge of Albertosauruss anatomy than is available for most other tyrannosaurids. The discovery of 26 individuals at one site provides evidence of pack behavior and allows studies of ontogeny and population biology, which are impossible with lesser-known dinosaurs. Albertosaurus was smaller than some other tyrannosaurids, such as Tarbosaurus and Tyrannosaurus. Typical Albertosaurus adults measured up to 9 m (30 ft) long, while rare individuals of great age could grow to be over 10 meters (33 feet) long.
Therizinosaurus cheloniformis was a therizinosaurid therizinosaur that lived in Asia during the Late Cretaceous(specifically 70 million years ago). Therizinosaurus was the largest of it's kind, growing up to approximately 10 meters (33 ft) long and an estimated weight of 5 tonnes with claws about a meter(3 feet) long. Fossils of this species were first discovered in Mongolia and were originally thought to belong to a turtle-like reptile (hence the species name, T. cheloniformis – "turtle-formed"). It is known only from a few bones, including gigantic hand claws, from which it gets its name. Therizinosaurus was part of the Therizinosaurs (or segnosaurs) which were herbivorous or omnivorous theropods that are known for their large claws on their hands. Therizinosaur fossils have been found in Early through Late Cretaceous deposits in Mongolia, the People's Republic of China and western North America. Various features of the forelimbs, skull, and pelvis unite these finds as belonging into the maniraptorans, meaning that these animals were close relatives to birds.
Giganotosaurus carolinii is a carcharodontosaurid carnosaur of the giganotosaurini that lived in South America during the Late Cretaceous(specifically from 98 to 97 million years ago). Its name means giant southern lizard. 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 12 to 12.25 m (39 to 40ft), a skull 1.53 to 1.80 m (5.0 to 5.9 ft) in length, and a weight of 6.2 to 6.8 t (6.2 to 6.8 short tons). The dentary bone that belonged to a supposedly larger individual has been used to extrapolate a length of 13.2 m (43 ft). However, this dentary bone is no longer valid meaning that its a false size. Giganotosaurus remains to suggest that Giganotosaurus had a strong neck and was stout and powerful, which supported the large head. Its teeth were like sharks cutting edges with serrated teeth for slashing into its prey.
Acrocanthosaurus atokensis is a carcharodontosaurid carnosaur that existed in North America during the Early Cretaceous(specifically from 116 to 110 million years ago). Acrocanthosaurus was a bipedal predator. As the name suggests, it is best known for the high neural spines on many of its vertebrae, which most likely supported a ridge of muscle over the animal's neck, back, and hips. Acrocanthosaurus was one of the largest theropods in North America. The largest known specimen (NCSM 14345) is estimated to have measured 11.5 m (38 ft) from snout to tail tip and weighed 5.7 t (6.3 short tons) to 6.2 t (6.8 short tons), Its skull alone was nearly 1.3 m (4.3 ft) in length. Like the Carnotaurus, Acrocanthosaurus had a slightly stout head. But the jaws were its primary killing weapon using teeth shaped as slashing teeth rather than like Spinosaurus, gripping teeth.
Saurophaganax maximus ("lord of lizard-eaters") is aallosaurid carnosaur from North America during the Late Jurassic (specifically about 150 million years ago). Some paleontologists consider it to be a species of Allosaurus (which would make it A. maximus). Saurophaganax represents a very large Morrison allosaurid characterized by horizontal laminae at the bases of the dorsal neural spines above the transverse processes and "meat-chopper" chevrons. The maximum size of S. maximus has been estimated at about 10.5 meters (34 ft), and around 3 tonnes (3.0 long tons; 3.3 short tons) in weight.
Deinocheirus mirificus is a large ornithomimosaur of the Deinocheiridae that lived during the Late Cretaceous(specifically from 71 to 69 million years ago) in Asia. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Nemegt Formation of Mongolia. In 1970, this specimen became the holotype of Deinocheirus mirificus; the genus name is Greek for "horrible hand". No further remains were discovered for almost fifty years, and its nature remained a mystery. Two more complete specimens were described in 2014, which shed light on many aspects of the animal. Parts of these new specimens had been looted from Mongolia some years before but were repatriated in 2014. Deinocheirus was unusual for aornithomimosaur, the largest of the clade at 11 meters (36 ft) long, and weighing 6.36 tons (14,000 lb). Though it was a bulky animal, it had many hollow bones which saved weight. The arms were among the largest of any bipedal dinosaur at 2.4 m (7.9 ft) long, with large, blunt claws on its three-fingered hands. The legs were relatively short and bore blunt claws. Its vertebrae had tall neural spines that formed a "sail" along with its back. The tail ended in pygostyle-like vertebrae, which indicate the presence of a fan of feathers. The skull was 1.024 m (3.36 ft) long, with a wide bill and a deep lower jaw, similar to those of hadrosaurs. The large claws may have been used for digging and gathering plants. Bite marks on Deinocheirus bones have been attributed to the tyrannosaurid Tarbosaurus.
Carcharodontosaurus saharicus was a large carcharodontosaurid carnosaur which lived in Africa from the Early to Late Cretaceous (specifically from 112 to 93 million years ago). Named after the shark genus Carcharodon which has the great white shark because its teeth looked like a shark's serrated teeth, like the Giganotosaurus. Carcharodontosaurus lived alongside Spinosaurus, but both avoided competing with each other by Spinosaurus becoming a semi-aquatic fish and croc hunter, while Carcharodontosaurus hunted the land-dwelling dinosaurs like Ouranosaurus, young Paralititan, Aegyptosaurus, and Rebbechisaurus, along with the occasional Rugops. Occasionally during droughts, Spinosaurus came on land to hunt because aquatic prey was scarce and would come into direct competition with Carcharodontosaurus. In the end, both of them went extinct at around the same time as their habitat and food supplies disappeared.
Sauroniops pachytholus is a basal carcharodontosaurid carnosaur known from the Late Cretaceous(specfically 100 million years ago) of Africa.
In the early twenty-first century, a collector donated a dinosaur skull bone to the Italian Museo Paleontologico di Montevarchi. He had acquired the specimen from a Moroccan fossil dealer, who again had bought the piece from local fossil hunters near Taouz. Its exact provenance is therefore uncertain. Later research showed that it presented a new species that was in 2012 reported and described by Andrea Cau, Marco Dalla Vecchia, and Matteo Fabbri. Sauroniops is only known from a single bone above the eye socket, which means not that much is known about it. The specific name is derived from Greek παχύς, pachys, "thick", and θόλος, tholos, "round building with a conical roof", in reference to the thick vaulted skull roof.
Sauroniops was probably a predator of the iguanodontids that it coexisted with. Living alongside its larger relative Carcharodontosaurus as well as the spinosaurid Spinosaurus.
Torvosaurus tanneri is a genus of carnivorous megalosaurid megalosaur that lived in Europe and North America during the Late Jurassic(specifically from 153 to 148 million years ago). It was a large, heavily built, bipedal carnivore, that could grow to a length of about 10 m (33 ft). Torvosaurus was among the largest carnivores of its time, together with Epanterias and Saurophaganax (which could be both synonyms of Allosaurus). Based on bone morphology, Torvosaurus is thought to have had short but very powerful arms.
Tarbosaurus bataar was the second largest Tyrannosaur known today, only smaller than the famous Tyrant lizard king. Tarbosaurus lived in Asia during the Late Cretaceous(specifically about 70 million years ago). Tarbosaurus name means Alarming lizard ( in Latin) hero (in mongolian). Tarbosaurus lived alongside and probably preyed upon the famous Protoceratops, Therizinosaurus, and Gallimimus, along with the less famous Saichania, Saurolophus, and Deinocheirus and lived alongside the small carnivore Velociraptor. Tarbosaurus had the smallest arms of ANY tyrannosaur known, including T.rex. Because many of its cousins have evidence of feathers, it is very likely Tarbosaurus had some, if only a few, feathers.
Some papers on Tarbosaurus have suggested it be a species of Tyrannosaurus instead of its own genus but were debunked. Because of the shape of Tarbosaurus’ skull, it seems to lack or has a poor binocular vision, like many tyranosaurs before Tyrannosaurus, including Albertosaurus. It seems to be that as Tyranosaurs got larger and larger, they have lesser and lesser teeth; this shows in Tarbosaurus as species like Albertosaurus and Gorgosaurus have more teeth, while Tyrannosaurus has less.
Yutyrannus huali is a tyrannosaur that lived in Asia during the Early Cretaceous(specifically about 124 million years ago). With a name meaning gorgeous feathered tyrant, and at two and a half tons and 20 feet long; Yutyrannus is the largest dinosaur discovered with feathers, being over ten times heavier than the last record holder, Beipiaosaurus. Beipiaosaurus actually lived in the same time and place and was the very likely prey of the tyrannosaur. Yutyrannus had a distinct crest of ridges on the top of its snout, possibly to attract mates. Three Yutyrannus fossils were found together, all of the different ages, suggesting that these animals lived in family groups.
Tyrannotitan chubutensis is a carcharodontosaurid carnosaur of the giganotosaurini from South America during the early Cretaceous period(specifically about 118 million years ago). It is closely related to other giant predators like Carcharodontosaurus and especially Giganotosaurus as well as Mapusaurus. The name means "Tyrant titan". Tyrannotitan is the geologically oldest known giant carcharodontosaurid along with the more basal Acrocanthosaurus from North America (both found in Aptian-age rock). Unlike other known carcharodontosaurids, this animal lacks pneumaticity extending into the sacral and caudal centra. The scapulocoracoid is fused, and much better developed than that of Giganotosaurus carolinii, yet the arm is very small compared to its relatives.
Cerapods are a group of Ornithischians that include the Ornithopods and the marginocephalians.
Pachycephalosaurus wyomingensis is a species of pachycephalosaurid that lived in the late Cretaceous period 68-66 mya in North America, most notably the Hell Creek Formation. Not much is known of this dinosaur, with only the skull, some teeth, and some other bones being known. Because of this, the rest of the body is based on the more complete Stegoceras validum. Pachycephalosaurus is famous for its hypothesized behavior of headbutting, much like horned/antlered ungulates. This has been backed up by recent evidence of cranial damage on the skull of Pachycephalosaurus BMR P2001.4.5. Alternatively, the animals may have used flank butting, where once intimidation of a rival failed, one animal would ram the flank of the other.
While the juvenile stages of Pachycephalosaurs are currently unknown, in 2007 it was hypothesized by Jack Horner that related genera Dracorex and Stygimoloch were actually juvenile stages of Pachycephalosaurus. While widely accepted by the scientific community, there is currently not enough evidence to fully support either side of this claim.
Stegoceras validum is a pachycephalosaurid that lived in what is now North America during the Late Cretaceous period(specifically from 77 to 74 million years ago). The first specimens from Alberta, Canada, were described in 1902. The generic name means "horn roof", and the specific name means "strong". Stegoceras was a small, bipedal dinosaur about 2 to 2.5 meters (6.6 to 8.2 ft) long, and weighed around 10 to 40 kilograms (22 to 88 lb). It had a rigid vertebral column and a stiffened tail. The pelvic region was broad, perhaps due to an extended gut. The skull was roughly triangular with a short snout and had a thick, broad, and relatively smooth dome on the top. The back of the skull had a thick "shelf" over the occiput, and it had a thick ridge over the eyes. Much of the skull was ornamented by tubercles (or round "outgrowths") and nodes (or "knobs"), many in rows, and the largest formed small horns on the shelf. The teeth were small and serrated. The skull is thought to have been flat in juvenile animals and to have grown into a dome with age.
Yandusaurus hongheensis is a basal ornithopod from the Middle Jurassic(specifically from 169 to 163 Million years ago) of Asia. When indicating the size of Yandusaurus was considerably larger than most of its counterparts, estimated at about three meters and about 140 kilograms. In its environment(the Dashanpu Formation) It coexisted with the stegosaur Huayangosaurus, the sauropod Shunosaurus, and the theropod Gasosaurus; just to name a few.
Parasaurolophus walkeri is a hardosaurid ornithopod of the lambeosaurinae that lived in North America during the Late Cretaceous Period(specifically from 70.5 to 66.5 million years ago). It was a herbivore that walked both as a biped and a quadruped. The genus that includes P. walkeri also has the other two species P. tubicen and P. cyrtocristatus. There are a possible species from Asia known as P. jiayensis although it is more commonly placed in the separate genus Charonosaurus. Remains are known from Alberta (Canada), New Mexico and Utah (United States), and possibly Heilongjiang, (China). The genus was first described in 1922 by William Parks from a skull and partial skeleton found in Alberta. Like most dinosaurs, the skeleton of Parasaurolophus is incompletely known. The length of the type specimen of P. walkeri is estimated at 9.5 m (31 ft), and its weight is estimated at 2.5 tonnes (2.8 short tons). Its skull is about 1.6 m (5 ft 3 in) long, including the crest, whereas the type skull of P. tubicen is over 2 m (6 ft 7 in) long, indicating a larger animal. Its single known forelimb was relatively short for a hadrosaurid, with a short but wide shoulder blade. The thighbone measures 103 cm (41 in) long in P. walkeri and is robust for its length when compared to other hadrosaurids. The upper arm and pelvic bones were also heavily built.
Kosmoceratops richardsoni is a chasmosaurine ceratopsian which lived in North America during the Late Cretaceous period(specifically from 76 to 75 million years ago). Its fossils have been recovered from the Kaiparowits Formation in the Grand Staircase-Escalante National Monument. It was first named by Scott D. Sampson, Mark A. Loewen, Andrew A. Farke, Eric M. Roberts, Catherine A. Forster, Joshua A. Smith, and Alan L. Titus in 2010 along with the chasmosaurine genera Utahceratops (also from the monument) and Vagaceratops (from Alberta). Kosmoceratops and many other chasmosaurines inhabited the island continent Laramidia that now forms western North America. During the Late Cretaceous, Laramidia was separated from Appalachia, the eastern North American landmass, by the Western Interior Seaway. A major evolutionary radiation took place on Laramidia, with many major dinosaur clades known from across the island continent such as most of the tyrannosaurids, many different kinds of hadrosaurs, and pretty much all of the chasmosaurines.
Corythosaurus casuarius is a hadrosaurid ornithopod of the lambeosaurinae from North America during the Late Cretaceous(specifically from 77 to 75.7 million years ago). Relatives of Corythosaurus include Nipponosaurus, Velafrons, Hypacrosaurus, and Olorotitan. Corythosaurus has an estimated length of 9 meters (30 ft), and has a skull, including the crest, that is 70.8 centimeters (27.9 in) tall. Corythosaurus is known from many complete specimens, including the nearly complete holotype found by Brown in 1911. The holotype skeleton is only missing the last section of the tail, and part of the forelimbs, but was preserved with impressions of polygonal scales. Corythosaurus is known from many skulls with tall crests. The crests resemble the crests of the cassowary and a Corinthian helmet, which is the reason it has its name.
Shantungosaurus giganteus is a saurolophine hadrosaurid ornithopod found in Asia during the Late Cretaceous(specifically from around 80 million years ago). Shantungosaurus is so far the largest hadrosauroid in the world that we know of: the greatest length of its femur is about 1.7 meters, and the greatest length of its humerus is about 0.97 meters. Shantungosaurus giganteus is one of the largest known ornithischians, the type skull is 1.63 meters (5.3 ft) long and the composite skeleton mounted at the Geological Institute of China in Beijing measures 14.7 meters (48 ft) in length while another mounted skeleton, originally referred to "Zhuchengosaurus maximus", measures 16.6 meters (54 ft) in length. The largest individuals may have weighed as much as 16 tonnes (18 short tons). Like all other hadrosaurs, its beak was toothless. At the back of its jaws, however, were around 1,500 tiny tightly-packed chewing teeth. A large hole near its nostrils may have been covered by a loose flap of skin, which could be inflated to make sounds.
Saurolophus osborni is a large saurolophine hadrosaurid ornithopod of the saurolophini that lived in North America while Saurolophus angustirostris lived in Asia during the Late Cretaceous(specifically from about 70 to 68 million years ago). Their distribution in both North America and Asia make it one of the few genera of dinosaurs known from multiple continents. It is distinguished by a spike-like crest which projects up and back from the skull. Saurolophus was a herbivorous dinosaur which could move about either bipedally or quadrupedally. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky. Saurolophus is known from material including nearly complete skeletons, giving researchers a clear picture of its bony anatomy. S. osborni, the rarer species are mostly known from Alberta, was around 9.8 m (32 ft) long, with its skull 1.0 meters (3.3 ft) long and the entire animal weighing about 1.9 tonnes (2.1 tons). S. angustirostris, the Mongolian species, was larger in size; the type skeleton is roughly 12 meters (39 ft) long, and larger remains are reported. The largest known skull of S.angustirostris measures 1.22 meters (4.0 ft) in length. Aside from size, the two species are virtually identical, with differentiation hindered by lack of study.
Iguanodon bernissartensis is a Iguanodontid ornithopod that existed in Europe during the Early Cretaceous(specifically from 126-125 million years ago). While only two species of Iguanodon exist today with I. bernissartensis being the type species; there used to be many different species under its belt that spanned from the Late Jurassic to the Late Cretaceous all over the world. Iguanodon were large, bulky herbivores. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food. Iguanodon were bulky herbivores that could shift from a bipedal walk to a quadrupedal walk although studies suggest that older animals became more and more comfortable on walking on four legs. The type species, I. bernissartensis, is estimated to have weighed about 3.08 tonnes (3.4 tons) on average, and measured about 10 meters (33 feet) long as an adult, with some specimens possibly as long as 13 meters (43 feet). These animals had large, tall but narrow skulls, with toothless beaks probably covered with keratin, and teeth like those of iguanas, but much larger and more closely packed.
Maiasaura peeblesorum is a large saurolophine hadrosaurid ornithopod of the Brachylophosaurini that lived in North America during the Late Cretaceous(specifically from 79 to 76.7 million years ago).
The first fossils of Maiasaura were discovered in 1978. In 1979, the genus was named. The name refers to the find of nests with eggs, embryos and young animals, in a nesting colony. These showed that Maiasaura fed its young while they were in the nest, the first time such evidence was obtained for a dinosaur. Hundreds of bones of Maiasaura have been dug up.
Maiasaura was about nine meters long. Young animals walked on their hind legs, adults on all fours. Maiasaura was probably closely related to Brachylophosaurus. Maiasaura were large, attaining a maximum known length of about 9 meters (30 ft). They had a flat beak typical of hadrosaurids, and thick noses. They had a small, spiky crest in front of the eyes. This crest may have been used in headbutting contests between males during the breeding season.
Eotriceratops xerinsularis is a chasmosaurine ceratopsian of the Triceratopsini which lived in North America during the Late Cretaceous period(specifically from 68-67.6 million years ago). The holotype skull has been estimated to have had an original length of around 3 meters (9.8 ft). It has been estimated that this specimen had a total body length of about 9 meters (29.5 ft). In 2010, Paul estimated its length at 8.5 meters, its weight at ten tonnes. Eotriceratops was placed in the Chasmosaurinae in 2007. In a cladistic analysis, it was recovered as a close relative of Triceratops, Nedoceratops and Torosaurus, being considered as a sister genus to Triceratops. In view of its greater age, the describing authors considered it more likely that Eotriceratops was, in fact, basal to, lower in the evolutionary tree than, the other three genera.
Ankylosaurus magniventris is a Ankylosaurid Ankylosaur that lived in North America during the Late Cretaceous Period(specifically from about 68 to 66 million years ago). The genus name means "fused lizard" and the specific name means "great belly". A handful of specimens have been excavated to date, but a complete skeleton has not been discovered. Though other members of Ankylosauria are represented by more extensive fossil material, Ankylosaurus is often considered the archetypal member of its group, despite having some unusual features.
The largest known ankylosaurid, Ankylosaurus is estimated to have been between 6.25 and 8 meters (20.5 and 26.2 feet) long, 1.7 meters (5.6 feet) tall, and weighed about 4.8–8 tonnes (11,000–18,000 lb). It was quadrupedal, with a broad, robust body. It had a wide, low skull, with two horns pointing backward from the back of the head, and two horns below these that pointed backward and down. Unlike other ankylosaurs, its nostrils faced sideways rather than towards the front. The front part of the jaws was covered in a beak, with rows of small, leaf-shaped teeth further behind it. It was covered in armor plates, or osteoderms, with bony half-rings covering the neck, and had a large club on the end of its tail. Bones in the skull and other parts of the body were fused, increasing their strength, and this feature is the source of the genus name.
Stegosaurus stenops is a stegosaurid stegosaur that lived in North America and Europe during the Late Jurassic(specifically from 155 to 150 million years ago). These were large, heavily built, herbivorous quadrupeds with rounded backs, short forelimbs, long hind limbs, and tails held high in the air. Due to their distinctive combination of broad, upright plates and tail tipped with spikes, Stegosaurus is one of the most recognizable kinds of dinosaur. The function of this array of plates and spikes has been the subject of much speculation among scientists. Today, it is generally agreed that their spikes were most likely used for defense against predators, while their plates may have been used primarily for display, and secondarily for thermoregulatory functions. Stegosaurus had a relatively low brain-to-body mass ratio. It had a short neck and a small head, meaning it most likely ate low-lying bushes and shrubs. A related species, Stegosaurus ungulatus, is the largest known of all the stegosaurs (bigger than related genera such as Kentrosaurus and Huayangosaurus).
Edmontonia was an armored dinosaur, part of the nodosaur family from the Late Cretaceous Period. It is named after the Edmonton Formation (now the Horseshoe Canyon Formation in Canada), the unit of rock it was found in. Edmontonia was bulky, broad and tank-like. Its length has been estimated at about 6.6 m (22 ft). In 2010, Gregory S. Paul considered both main Edmontonia species, E. longiceps and E. rugosidens, to be equally long at six meters and weigh three tonnes. Edmontonia had small, oval ridged bony plates on its back and head and many sharp spikes along its sides. The four largest spikes jutted out from the shoulders on each side, the second of which was split into subspines in E. rugosidens specimens. Its skull had a pear-like shape when viewed from above. Its neck and shoulders were protected by three half-rings made of large keeled plates.
Kentrosaurus (/ˌkɛntroʊˈsɔːrəs/ KEN-tro-SAWR-əs) is a genus of stegosaurian dinosaur from the Late Jurassic of Tanzania. The type species is K. aethiopicus, named and described by German paleontologist Edwin Hennig in 1915. Often thought to be a "primitive" member of the Stegosauria, several recent cladistic analyses find it as more derived than many other stegosaurs, and a close relative of the larger Stegosaurus from the North American Morrison Formation within the Stegosauridae.
Fossils of K. aethiopicus have been found only in the Tendaguru Formation, dated to the late Kimmeridgian and early Tithonian ages, about 152 million years ago. Hundreds of bones were unearthed by German expeditions to German East Africa between 1909 and 1912. Although no complete skeletons are known, the remains provided a nearly complete picture of the build of the animal. Like most other stegasouridae its spikes were made of mostly keratin.
Kentrosaurus generally measured around 4.5 meters (15 ft) in length as an adult and weighed about one tonne (1.1 tons). It walked on all fours with straight hindlimbs. It had a small, elongated head with a beak used to bite off plant material that would be digested in a large gut. It had a, probably double, row of small plates running down its neck and back. These plates gradually merged into spikes on the hip and tail. The longest spikes were on the tail end and were used to actively defend the animal. There also was a long spike on each shoulder. The thigh bones come in two different types, suggesting that one gender was larger and more stout than the other.
Dacentrurus (meaning "tail full of points"), originally known as Omosaurus, was a large stegosaur of the Late Jurassic Period (154 - 150 mya) of Europe. Its type species, Omosaurus armatus, was named in 1875, based on a skeleton found in England. In 1902 the genus was renamed into Dacentrurus because the name Omosaurus had already been used for a crocodilian. After 1875, half a dozen other species would be named but perhaps only Dacentrurus armatus is valid.
Finds of this animal have been limited and much of its appearance is uncertain. It was a heavily built quadrupedal herbivore, adorned with plates and spikes. Dacentrurus was a large stegosaurid. Some specimens have been estimated to reach lengths between 7–8 m (23–26 ft) and to weigh up to 5 t (5.5 short tons). Many books claim that Dacentrurus was a small stegosaur, when in fact finds such as a 1.5 meters (4.9 ft) wide pelvis indicate that Dacentrurus was among the largest of them.
Barosaurus is a Late Jurassic Sauropod related to Diplodocus and Apatosaurus. Like other sauropods, it has a long, slender neck, stout, column-like limbs, and a long whip-like tail.
Barosaurus fossils are found in the USA and Tanzania and the average skeleton is about 92 feet (28m) long.