Jurassic World – When Did the Dinosaurs Really Live?

The Jurassic Park franchise has long had the tagline: “An adventure 65 million years in the making.” A friend of mine recently asked: “Did the raptors really live 65 million years ago?”

We commonly view “dinosaur” as a monolithic concept; at some point, Earth was populated by a group of huge and fascinating lizards. This was a mere phase in our planet’s development leading up to us.

But what we may not realize is that dinosaurs inhabited Earth for much, much longer than we have so far; and they did not all live at the same time. Indeed, many of the dinosaurs seen living side-by-side in Jurassic Park never did that – many of them were more distant from each other in time than they are distant from us.

So let’s take a quick look at the timeline of some of Jurassic Park‘s most popular dinosaurs:

Stegosaurus – Always a fan favorite, this massive plate-backed herbivore, like all dinosaurs, looks like nothing we’ve ever seen in the modern world! It lived from 155-150 million years ago in what is now western North America. Much like the modern deer, “stegosaurus” refers not to a single species, but to a whole family of related species of animal with similar features.

Stegosaurus_size_Piotr Jaworski_CC_3.0

Debate has raged over how exactly Stegosaurus moved. When it was first discovered, due to its front legs being much shorter than its back legs, it was thought to walk on just the back two legs – giving rise to early images of a giant, hulking animal with spikes running down its back which arguably inspired the design for the Japanese Godzilla.

However, after realizing how truly massive and heavy the Stegosaurus was, paleontologists concluded that it walking on two legs was not feasible. There is still disagreement among paleontologists about whether the Stegosaurus’ muscles were strong enough for it to stand on its back two legs in order to reach leaves growing high off the ground, or if it was strictly a lumbering low-brush feeder.

Kind of weird to think about those wandering around North America just like deer do today.

Photograph by Alina Zienowicz, licensed under Creative Commons 3.0.

Spinosaurus – This star of Jurassic Park 3 lived in northern Africa from 112-97 million years ago. As stated in the movie, it was among the largest land carnivores to ever live – possibly larger than T. rex or Gigantosaurus. Reaching nearly 50 feet long, it was almost as big as the fictional monster from Jurassic WorldIndominus rex.  It is rather difficult to believe that such a predator ever really existed – just walking around, hunting!

Spinosaurus_Tierpark_Germendorf_Doc Strangepork_CC_3.0

Photograph by Doc Strangepork, licensed under Creative Commons 3.0.

Scientists do not know what the enormous “sail” on Spinosaurus’ back was used for. Some speculate that it may have been used to regulate the Spinosaurus’ temperature, as the “sail” could have been used either for cooling like an elephants’ ears (which are so big to allow a large surface area for blood to flow through and cool off when coming from the animal’s hot core), or for warming, giving the Spinosaurus a huge amount of surface area to be warmed by the sun.

Others suggest that the sails were predominantly a mating display, or to make the Spinosaurus look bigger and more intimidating to other animals (which hardly seems necessary!).

Utahraptor – The use of “velicoraptor” in Jurassic Park is actually somewhat misleading. The species with the scientific name “velociraptor” is much smaller than the raptors portrayed in Jurassic Park – but Speilberg felt (correctly!) that the name “velociraptor” sounded much scarier than the name of the raptor species that is that big, named Utahraptor after the U.S. state in which their first fossils were discovered.


Graphic by Matt Martyniuk, licensed under Creative Commons 3.0.

Utahraptor has quite a story. It had actually not been discovered when the first Jurassic Park movie started filming. Spielberg simply felt that the raptors should be that big, human-sized, to provide a perfect match for its human characters. The first specimen of Utahraptor was discovered while Jurassic Park was filming – thus proving Spielberg right that there really were raptors that were that big and that scary.

In fact, the species was almost named Utahraptor spielbergi, with Spielberg initially offering to fund further research into the species.

Unfortunately, by 65 million years ago, the giant Utahraptor was long-extinct. It had lived from roughly 121-127 million years ago.


Photograph by Krugerr, licensed under Creative Commons 3.0.

Velociraptor – The species truly named velociraptor, on the other hand, lived in Mongolia, much later than Utahraptor – from about 71-75 million years ago. And this raptor would not have come up to a modern man’s waist!

Interestingly, it is now thought to be likely that both Utahraptor and velociraptor had feathers. Although feathers have never been discovered fossilized with Utahraptor bones, so many of its relatives appear to have had feathers that it is difficult to imagine why Utahraptor would be the exception.

So the next time you think about Jurassic Park‘s raptors, remember: they’re Utahraptors, not velociraptors. They were almost as long-extinct in the time of the velociraptor as velociraptors are to us today. And they almost certainly had feathers.

Velociraptor_Noemy García García_CC_2.5_Spain

This is a velociraptor. Note the strong resemblance to a chicken. Photograph by Noemy García García, licensed under Creative Commons 2.5, Spain.

Triceratops – An ever-distinctive dinosaur with its combination of bull-like brow horns, rhinocerous-like nose horn, bird-like beak, and the elegant bony fringe radiating far out behind its skull, Triceratops is another fearsome-looking herbivore. Why were so many dinosaurs pointy? Hard to say – maybe it’s just that we only pay attention to the pointy species!


Graphic by Marmelad, licensed under Creative Commons 2.5.

The leading theory on Triceratops’ impressive headgear right now is that, much like a buck’s elaborate antlers, they were used primarily as mating displays. In this capacity they may also have been used for combat with romantic rivals – and there is some evidence that they may also have provided a good defense against predators that shared their habitat, like Tyrannosaurus rex.


This photo has been released by its creator into the public domain.

Triceratops lived in North America from 68-65 million years ago, making it the only dinosaur on this list to actually perish in the extinction that destroyed dinosaurs as an entire genre of creature.

As you can see, everyone else on this list went extinct from natural causes long before this asteroid impact – which really gives us cause to think about the fact that dinosaurs were a dominant genre of creature, ruling the Earth and developing fearsome size, strength, and speed, for much, much longer than hominids have been around.

Like “stegosaurus,” “triceratops” actually refers to a family of multiple different, related species.

Triceratops lived “only” about 7 million years after Velociraptor vanished from the fossil record – in other words, they lived 1,400 spans of recorded human history apart. But these two lived on separate continents, with velociraptors likely stealing eggs and eating small mammals and reptiles in Asia, and triceratops fighting T. rex (yes, that really happened) and each other across North America.

Tyrannosaurus rex
– Has there ever been a more perfectly scary, intimidating creature? It’s huge, it has a huge head that makes the whole animal seem even bigger than it really is, and it has serrated steak knives as long as your arm for teeth.

Largesttheropods_Matt Martyniuk_CC_3.0

Graphic by Matt Martyniuk, licensed under Creative Commons 3.0.

And it is all wrapped up in mystery. What in God’s name is going on with those tiny arms, which were seemingly far too short to possibly reach anything without sending the T. rex into hilariously awkward contortions – yet which apparently boasted incredibly strong muscles, suggesting that they were not only used, but used for something very important.

Was it a predator, or a scavenger? It had possibly the strongest bite of any animal in history, giving it something in common with modern scavengers, the hyenas, who use their strong bite, unparalleled among mammals, to chew bones in order to get at nutrient-rich marrow that the predator who took down the carcass couldn’t reach.

Its brain case suggests enormous olfactory bulbs, which gives it something in common with the modern scavenger the vulture, who use their acute sense of smell to detect rotting corpses from miles away. The T. rex was so massive that it is difficult to imagine it successfully hiding or giving chase to animals with any ability to run away.

And yet it has eyes that point forward, giving it binocular vision better than that found in hunting birds of prey today. This would have no obvious use for a scavenger, whose sense of smell would guide it more than vision. Several herbivores have also been found to have healed wounds, apparently caused by Tyrannosaurus teeth – the “healing” part suggesting that the T. rex attacked while the animal was still alive and well.

In light of all this evidence, most paleontologists now believe that T. rex was both an active predator and a hardcore scavenger, eating what others left behind and breaking into bones to get that delicious marrow. A truly formidable animal, then, whose binocular vision, unparalleled bite strength, and possibly bizarre behaviors (what’s up with the arms?) may not have been done justice by the Jurassic Park movies!


Photography by FunkMonk, licensed under Creative Commons 3.0.

For one last perspective check, it’s worth noting that Stegosaurus lived nearly 100 million years before T. rex did – and T. rex perished in the fireball that ended the Cretaceous Era only 65 million years before we came about. This means that Stegosaurus was much more ancient and long-extinct in T. rex’s day than T. rex is to us!

Really gives you some perspective.

In the words of John Hammond and his successor, “Jurassic Park exists to remind us of how very small we are. You can’t put a price on that.”

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2 Responses to Jurassic World – When Did the Dinosaurs Really Live?

  1. Pingback: Perspective Check: History Lesson, Part 1 | Perspective Check

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