Identifying the largest, often deadly, dinosaurs ever built isn't as easy as you might think: Sure, these giant beasts left huge fossils, but unearthing a complete skeleton is very rare (tiny, bite-sized dinosaurs tend to fossilize them all at once, but bulky giants like Argentinosaurus are usually only able to pass through one, huge neck bone). In the slides below, you'll find the largest dinosaurs, as well as the largest pterosaurs, crocodiles, snakes, and turtles, based on the current state of research.
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The largest herbivorous dinosaur - Argentinosaurus (100 tons)
Argentinosaurus.
Although paleontologists claim to have discovered larger dinosaurs, Argentinosaurus was the largest dinosaur and its size was supported by convincing evidence. The giant titanosaurus (named after Argentina, whose remains were discovered in 1986) was about 120 feet long from head to tail and weighed nearly 100 tons.
Only one of the vertebrae of Argentinosaurus was more than four feet thick. Other contenders for the lesser-known title of "biggest dinosaur" include Futalognkosaurus, Bruhathkayosaurus, and Amphicoelias; A new contender, yet unnamed, was recently discovered in Argentina, about 130 feet long.
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The largest carnivorous dinosaur - Spinosaurus (10 tons)
Spinosaurus.
You might think the winner of this category was T. rex, but it's now believed that Spinosaurus (which had a huge crocodile-like nose and a skin sail emerging from its back) was slightly heavier, weighing 10 tons. Spinosaurus was not only large, but also agile: recent evidence suggests that it was the world's first swimming dinosaur to be discovered. (By the way, some experts insist that the biggest meat eater is the South American giant dragon, which may be comparable to, and sometimes surpassing, its North African cousin.)
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Largest Raptor - Utah Raptor (1,500 lb)
Utah raptor (Early Cretaceous) at the Museum of Ancient Life (Leah, Utah).
Velociraptors have received all the media coverage since their starring role in Jurassic Park, but this chicken-sized carnivore is very anemic next to Utah Raptor, which weighed up to 1,500 pounds (a full 20 feet long). Strangely, Utahraptor lived tens of millions of years longer than its more famous (and smaller) cousin, reversing the general evolutionary rule that tiny ancestors evolved into larger offspring. The scary thing is that the Utah raptor's massive curved hind claws — which it used to hack and viscerate prey, possibly including iguanodons — measured nearly a foot long.
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The largest tyrannosaurus - Tyrannosaurus rex (8 tons)
Poor Tyrannosaurus Rex: Once considered (and often is) the largest carnivorous dinosaur in the world, it has since been surpassed by Spinosaurus (from Africa) and Giganotosaurus (from South America). Thankfully, though, North America can still claim the world's largest tyrannosaurus, a category that also includes predators that aren't exactly the size of Tyrannosaurus rex, such as Taborosaurus and Albertasaurus. (By the way, there is evidence that Tyrannosaurus rex females weigh about half a ton more than males — a classic example of kingdom sexual selection in theropods.)
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The largest horned frilled dinosaur - Titan Ceratops (5 tons)
Pentagonosaurus - the largest skull of the Guinness Book of World Record holders.
If you haven't heard of Titanic Horned Face, "Titanic Horn Face," you're not alone: This ceratopsian dinosaur was only recently diagnosed by an existing mesosaurus species on display at the Oklahoma Museum of Natural History. If its genus name holds. Titan Ceratops would slightly outperform the largest Triceratops species, with adult individuals measuring 25 feet from head to tail and weighing up to 5 tons. Why did Titan Ceratops have such a huge, ornate head? The most likely explanation: sexual selection, with males' more prominent heads more attractive to females.
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The largest duckbill dinosaur - Magnapolis (25 tons)
As a general rule, the largest dinosaur of the Mesozoic era was aptly Titanosaurus, represented in this list by Argentinosaurus (slide #2). But there were also some Hadrosaurus, or duck-billed dinosaurs, that grew to resemble Titanosaurus, the main of which was the North American 50-foot-long, 25-ton Magnapaulia. Despite its size, "Big Paul" (named after Paul Jr., chairman of the board of directors of the Los Angeles Museum of Natural History, Jr. Paul G. Hagaa, Jr. may be able to run on two hind legs when chased by predators, which must be an impressive sight!
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The largest dinosaur bird - Giant Raptor (2 tons)
Great-raptor skeleton mount.
Given its name, you might think that Greatraptor should be on this list as the largest bird of prey, which is currently honored by the Utah Raptor (slide #4). But although this Central Asian "dinosaur bird" is more than twice the size of its North American cousin, strictly speaking it is not a bird of prey, but a milder theropod dinosaur species called Oviraptorosaurus (after the genus Poster of this species, Oviraptorosaurus). One thing we don't yet know about the great raptor is whether it preferred to eat meat or vegetables; For the sake of its late Cretaceous contemporaries, let's hope it was the latter.
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The largest bird imitates a dinosaur - Deinocheirus (6 tons)
Deinocheirus, the "terrible hand," took a long time to be correctly identified by paleontologists. The huge forelimbs of this feathered theropod dinosaur were discovered in Mongolia in 1970, and it wasn't until 2014 (after more fossil specimens were unearthed) that Deinocheirus was finally identified as an ornithosaur, or "bird mimicking" dinosaur. The six-ton Deinocheirus, at least three to four times the size of North American birds like Gallimimus and Ornithomimus, is a recognized vegetarian, wielding its massive claws in its forehand like a pair of Cretaceous sickles.
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The largest prosauropod dinosaur - Riogasaurus (10 tons)
Rioga dragon skull casting, Copenhagen.
Tens of millions of years before giant sauropods such as diplodocus and Apatosaurus ruled the earth, there were prosauropods, a smaller, occasionally bipedal herbivore descended from the ancestors of the late Jurassic behemoths. The largest prosauropod ever discovered, the South American Rigalosaurus is a 30-foot-long, 10-ton phytovorous animal from the late Triassic more than 200 million years ago. You can detect the primitive sauropod dinosaur of the Riogasaurus in its relatively long neck and tail, although its legs are much more elongated than its massive offspring.
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The largest pterosaur - Quetzalcoatl (35-foot wingspan)
Quetzalcoatl life resumes.
When measuring the size of pterosaurs, it is not the weight that is important, but the wingspan. The Late Cretaceous Quetzalcoatl could not have weighed more than 500 pounds in wet conditions, but it was the size of a small airplane and was probably able to glide long distances with its huge wings. (We say "probably" because some paleontologists speculate that Quetzalcoatl did not have the ability to fly, but instead stalked its prey on two legs, like terrestrial theropods.) Fittingly, this winged reptile is named after Quetzalcoatl, the long-extinct Aztec Quetzalcoatl.
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The largest crocodile - Caryophyllum (15 tons)
Dinosaur Park, Meat Dragon.
Better known as the "Super Crocodile," the 40-foot-long Sarcosuchus weighs 15 tons — at least twice as long and ten times as heavy as the largest crocodile alive today. Despite its huge size, Sarcosuchus appears to have lived a typical crocodile lifestyle, lurking in African rivers in the mid-Cretaceous and launching itself at any dinosaur unlucky enough to get closer. Sarcosuchus may occasionally become entangled with Spinosaurus, another river member on this list.
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The largest snake - Titan Noboa (2,000 lbs)
Titanoboa -- Smithsonian Museum of Natural History.
Sarcosuchus to the contemporary crocodile, Titanoboa to the contemporary snake: an incredibly giant ancestor that threatened small reptiles, mammals and birds in its lush habitat 60 or 70 million years ago. The 50-foot-long, one-ton Titanoboa wandered through the wet swamps of the early Paleocene in South America, like King Kong's Skull Island, and was home to an impressive array of giant reptiles (including the one-ton Carbonemys) just five million years after the dinosaurs went extinct.
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Largest sea turtle - Ah Echelon (2 tons)
"Archelon ischyros" from South Dakota 75 million years ago.
Let's put the turtle in perspective: The largest testicles alive today are leatherback turtles, which grow five feet from head to tail and weigh about 1,000 pounds. By comparison, the late Cretaceous Archelon was about 12 feet long and weighed about two tons — not just four times the size of a leatherback turtle, eight times the size of a Galapagos tortoise, and twice as long as a mass beetle! Strangely, Archelon's fossilized remains came from Wyoming and South Dakota and were submerged under the western inland sea 75 million years ago.
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The largest ichthyosaurus - Shastasaurus (75 tons)
Ichthyosaurs, or "ichthyosaurs", were large dolphin-like marine reptiles that dominated the oceans of the Triassic and Jurassic periods. For decades, the largest ichthyosaur was thought to be Shounisaurus until the discovery of an oversized (75-ton) specimen of Shounylosaurus prompted a new genus, Shastasaurus (after Mount Shasta, California). Despite its size, Shastasaurus did not feed on fish and marine reptiles of the same size, but on molluscs cephalopods and other small marine life (making it roughly similar to the plankton-filtered blue whales that inhabit the world's oceans today).
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The largest dragon - Cronorsaurus (7 tons)
Cronorrone Queensland.
It is not for nothing that Kronosaurus was named after the mythical Greek god Kronos, who ate his own children. This fearsome multi-headed dragon — a family of marine reptiles characterized by a crouched torso, thick heads on a short neck and long, clumsy flippers — dominated the mid-Cretaceous oceans, eating almost anything (fish, sharks, other marine reptiles) occurred in its path. It was once thought that another famous polydragon, Liopleurodon, surpassed Kronosaurus, but now it appears that this marine reptile is about the same size, perhaps smaller.
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The largest plesiosaur - cartilaginosaurus (3 tons)
Elasmosaurus Skeleton - Burke Museum of Natural History and Culture, Seattle, Washington.
Cronorosaurus was the largest identified polydragon from the Cretaceous; But when it comes to plesiosaurs — a closely related family of marine reptiles with long necks, elongated trunks and streamlined flippers — Elasmosaurus prides itself on. Measuring about 45 feet from head to tail and weighing relatively petitely, weighing two or three tons, this slender seabed predator preys not on marine reptiles of the same size, but on smaller fish and squid. Elasmosaurus also featured prominently in the dispute between the famous 19th-century paleontologists Edward Drinker Cope and Othniel C. Marsh, Bone Wars.
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The largest mosadragon - mosadragon (15 tons)
Extinct Mosasaurus fossils – Maastricht Museum of Natural History.
By the end of the Cretaceous period, 65 million years ago, ichthyosaurs, polyosaurs, and plesiosaurs (see previous slides) were either extinct or in decline. Now the world's oceans are dominated by mosasaurs, ferocious, streamlined marine reptiles that eat everything - 50 feet long and 15 tons, and the mosasaurus is the largest and most ferocious mosasaur among them. In fact, the only creatures that can compete with the Mosasaurus and its ilk are slightly less giant sharks – cartilage killers who reached the apex of the seabed food chain after marine reptiles succumbed to K/T extinction.
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Largest main dragon - Smoak (2,000 lb)
In the early to middle Triassic, the dominant terrestrial reptiles were archosaurs, which were destined to evolve not only into dinosaurs, but also pterosaurs and crocodiles. Most archosaurs weighed only 10, 20, or 50 pounds, but the exception named Smok proves this rule: a dinosaur-like predator that tilts scales to full tons. In fact, Smoak was so big, and apparently not a true dinosaur, that paleontologists couldn't explain its presence in late Triassic Europe — a condition that could be remedied by finding additional fossil evidence.
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Largest Therapsid – Moschops (2,000 lbs)
Moschops capensis - Middle Permian in South Africa.
For all intents and purposes, Moschaopus was a moo cow of the late Permian: this slow, clumsy, not-so-bright creature that roamed the plains of southern Africa 255 million years ago, possibly in droves. Technically, Moschops is a therapsid, a family of humble reptiles that evolved into the first mammals tens of millions of years later. Here are some trivia to share with your friends: Back in 1983, Moschops was the star of its own children's show, in which the protagonist shared its cave with Diplodocus and Allosaurus (somewhat inaccurate).
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The largest butterfly-dragon - Cotyrosaurus (2 tons)
Specimen of Cochinococcus kozi from Norman, Oklahoma.
By far the most famous butterflysaur of all time is Dimetrodon, a crouching four-legged cerebellar Permian reptile often mistaken for a real dinosaur. However, the 500-pound Dimetrodon is just a tabby cat compared to the Cotylorhynchus, a lesser-known pelycosaur that weighs up to two tons (but lacks the characteristic rear sail that makes the Dimetrodon so popular). Unfortunately, Cyprusaurus, Dimetrosaurus, and all their compatriots went extinct 250 million years ago; Today, even distant relatives of reptiles are sea turtles and water turtles.