If you think Jurassic Park has told you everything you need to know about the prehistoric inhabitants of Earth, think again. These fascinating dinosaur facts will surprise you.

Long before the dawn of man, there walked giants who forever left their mark upon Earth. Dinosaurs lived on the planet for over 66 million years (over three times longer than humans so far) before their extinction, leaving us to scrape together what little information we can from their scattered remains.

And though we have just these remains — meaning that so much about these towering creatures “remains” a mystery — scientists have been able to uncover a staggering number of truly fascinating dinosaur facts:

The extraordinary length of the dinosaurs’ reign can be difficult to comprehend. In fact, the gap between when Stegosaurus lived and when T. rex lived is greater than the gap between the latter and the present. You’re closer to T. rex on the Earth’s timeline than Stegosaurus is.Wikimedia Commons

The chicken is the closest known modern relative to the T. rex.Wikimedia Commons

Though the T. rex catches a lot of flak for its seemingly wimpy arms, in terms of proportion the Canotaurus (above) had the smallest arms out of any known dinosaur species.Wikimedia Commons

The largest known carnivorous dinosaur is the Spinosaurus, which could grow to be over 50 feet long and weighed in at over 20 tonnes — three times the weight of a T. rex.Wikimedia Commons

On the other hand, the largest known herbivorous dinosaur, and the largest dinosaur overall, is the Argentinosaurus, which could grow to be 115 feet in length and weigh 100 tons (which is more than over a dozen elephants).Wikimedia Commons

It’s speculated that the Sauropods (long-necked dinosaurs like the Argentinosaurus) had stomachs that acted as fermentation chambers. As gas-producing bacteria would be needed to help process their fibrous diets, this would cause these creatures, the largest of all dinosaurs, to fart constantly.Wikimedia Commons

Although sauropods were enormous, most dinosaurs (like the ornithischian above) were actually quite small; tiny, frail bones are less likely to withstand the test of time, which is why paleontologists tend to discover the fossilized skeletons of giants.Wikimedia Commons

Among the tinier dinosaurs was Anchiornis, which was no bigger than a pigeon.Wikimedia Commons

Velociraptors, for example, were roughly the size of turkeys.Wikimedia Commons

The “Velociraptors” featured in “Jurassic Park” weren’t actually Velociraptors at all; they were based on a close — much larger — relative, dubbed the Utahraptor.Wikimedia Commons

Much like birds, many of even the toughest carnivorous dinosaurs (like the velociraptor, above) had hollow bones.Wikimedia Commons

One of the most stunning fossils ever discovered is aptly named “Fighting Dinosaurs.” It depicts a Protoceratops locked in battle with a Velociraptor; the epic struggle was more than likely cut short when a sand dune collapsed on the two dueling dinosaurs, freezing them in time.Wikimedia Commons

The first dinosaur bones ever discovered belonged to Megalosaurus and weren’t found until the 1820s.Wikimedia Commons

The term “dinosaur” wasn’t coined until 1842, by English paleontologist Sir Richard Owen; “dinosaur” translates to “terrible reptile.”Wikimedia Commons

Along with dental fossils, much of our knowledge of dinosaurs’ feeding habits comes from coprolites, fossilized feces.Wikimedia Commons

While dinosaurs walked the Earth, pterosaurs inhabited the air and plesiosaurs inhabited the water. This means that the well-known flying Pterodactyl (above) and swimming Liopleurodon aren’t technically considered dinosaurs.Wikimedia Commons

Some of the pioneering work in Jurassic marine life — including the discovery of the first ichthyosaur and plesiosaur skeletons — was done by English paleontologist Mary Anning. Sadly, her work was often overshadowed or outright stolen by the men working in her field.Wikimedia Commons

Scientists estimate, based on bone evidence, that some dinosaurs could have lived to be between 75 and 300 years old.Wikimedia Commons

Dinosaurs are divided into two groups, the lizard-hipped saurischian (A) and the bird-hipped ornithischian (B). Ironically enough, birds evolved from lizard-hipped dinosaurs.Wikimedia Commons

Dinosaurs lived within the Mesozoic Era, which included the Triassic, Jurassic, and Cretaceous periods, beginning 252 million years ago and ending 66 million years ago.Wikimedia Commons

Veins in Stegosaurus’ spinal plates suggested that they would not have been used as protective armor; more than likely, they were used to help the dinosaur cool off its massive body.Wikimedia Commons

The Stegosaurus, despite being nearly 30 feet in length and weighing up to 6,000 pounds, had a brain roughly the size of a walnut.Wikimedia Commons

One paleontologist, Othniel Charles Marsh, theorized that dinosaurs — particularly Sauropods — had a second braincase located near their posterior. Scientists now know this fact to be false.Wikimedia Commons

The Ankylosaurus’ club tail was fortified enough to smash through a T. Rex’s ankles.Wikimedia Commons

Scientifically speaking, there is no such thing as the famed Brontosaurus; its misidentification was a result of the Bone Wars, in which two paleontologists competed in discovering the most dinosaurs. Its true name is the Apatosaurus. However, new research from 2015 is attempting to disprove this assertion.Wikimedia Commons

Not all mammals fled from dinosaurs; Repenomamus — a badger-sized mammalian ancestor that existed over 125 million years ago — remains have been discovered with the remains of baby dinosaurs in their stomachs.Wikimedia Commons

Many dinosaurs, like the massive predator know as Cryolophosaurus (above), were so equipped for the cold that they were able to live in Antarctica.Wikimedia Commons

Dinosaurs’ long tails existed in order to help them keep their balance while running.Wikimedia Commons

Many dinosaur eggs could grow to be as large as basketballs.Wikimedia Commons

The Hadrosaur could have over 1,000 teeth at once and was able to grow new ones indefinitely.Wikimedia Commons

The asteroid that is believed to have wiped the dinosaurs out most likely struck Mexico’s Yuctan Peninsula.