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How accurate are the dinosaurs in Jurassic Park? Part 3

Updated: Jan 29, 2023

Back at it again! Here we are in part 3 where we question just how accurate are the dinosaurs inJurassic Park? In this instalment, we'll be looking at Pachycephalosaurus, Mamenchisaurus, Pteranodon, Ankylosaurus and Ceratosaurus.

Let's begin!


Still from Jurassic park 2 showing a pachycephalosaurus being captured
Image © Universal Pictures, image is fair use.

First seen in Jurassic Park: The Lost World when dinosaurs are being wrangled, 'Friar Tuck' is seen making lives difficult before being pursued. We see one of the consulting paleontologists give some exposition about Pachycephalosaurus, where he correctly states it was a dinosaur from the late Cretaceous. In fact, it was actually found in the Hell Creek formation, meaning it existed in the same environment as T.rex and Triceratops. BTEC Bakker also correctly states that the neck inserts into the skull at the bottom rather than the back, so that when Pachycephalosaurus lowers its head, the spine forms a near straight and rigid line to form a battering ram.

Overall, not bad. With the exception of the twisted JP hands (hands pointing downwards rather than inwards), this dinosaur looks pretty accurate. The only question to really arise is the size of how big the dinosaur could get. It could be fairly accurate, but size estimations seem to vary greatly, with many estimations placing the animal as quite a bit larger. If it was, you could argue that it was never stated that this wasn't a juvenile, but then we have to talk about ontogeny. Ontogeny is the process in which an organism changes its physical features as it reaches adulthood, much like tadpoles to frogs or stags growing antlers.

In the case of Pachycephalosaurus, it has been heavily hypothesised that the dome on the skull is an ontogenetic feature, since there are other, smaller relatives who seem to show no differences with Pachycephalosaurus other than size and skull ornamentation. One example is the awesomely named Dracorex hogswartia, which is now generally accepted to have likely been a juvenile Pachycephalosaurus.

The same can be said for Stygimoloch spinifer, which is slightly larger than Dracorex, with slightly more of a dome, but smaller than Pachycephalosaurus with slightly less of a dome, so Stygimoloch could represent an adolescent, mid-stage of ontogeny.

In summary, this depiction is pretty close!

Actual Depiction of the animal (showing a speculative, thick and scaly tail that is somewhat gecko-like):

Artist's reconstruction of a pachycephalosaurus
Art belongs to Chris Masnaghetti


Still from Jurassic park 2 showing a truck chasing after dinosaurs
Image © Universal Pictures, image is fair use.

I'm going to be really honest with you guys, I had no idea this was a Mamenchisaurus. Our brief glimpse of the dinosaur in Jurassic Park 2: The Lost World is in the same scene what we see the Pachycephalosaurus. Since the sighting is brief, it's hard to pinpoint just how much is inaccurate about this particular dinosaur, however, it does seem to be suffering from the 'generic sauropod' treatment (which probably explains why I didn't even know it was in the film).

Mamenchisaurus in real life looked far more brachiosaur-like in terms of its overall body proportions. The neck of this dinosaur was around half of its total body length, with its shoulders slightly higher than its hips. The Mamenchisaurus in Jurassic Park 2 seem to look like any other long-neck depicted in media. With this comes the usual problems that I highlighted in Part 1!

Actual depiction of the animal:

An artist's reconstruction of a Mamenchisaurus
Image credit:


Image of a pterosaur sitting on a branch in front sunlight
Image © Universal Pictures, image is fair use.

If you've ever read my post on what makes a dinosaur a dinosaur, you'll know that a pterosaur is not a dinosaur and if you know me on a personal level, you know how much it irritates me when people call them the 'flying dinosaurs', but I digress.

Though it's not technically a dinosaur, a pterosaur is about as close to a dinosaur that you can get without being a dinosaur and pterosaurs are so synonymous with dinosaurs that it would be rude to miss them out.

First up, let's clear up some confusion over name use. The pterosaur that you normally think of when you hear the word 'Pterodactyl' is likely Pteranodon longiceps. 'Pterodactyl' is an informal term (derived from the genus Pterodactylus) often used to refer to many pterosaurs, similar to the word raptor.

Now that's out of the way, let's look at this Pteranodon seen at the end of Jurassic Park 2: The Lost World. This guy was somewhat accurate at the time, however, our understanding has changed quite a lot since then. First up, the wings. The wings of a Pterosaur were skin membranes connected to their bodies from an extended fifth digit (the 'pinky' finger). It was recently discovered that the ends of these wings didn't actually end in a sharp point, but rather a rounded end.

Another feature seen in most pterosaurs are pycnofibers, which are a type of feather covering what would have very much resembled fur. The fact that pterosaurs are not dinosaurs but share a common ancestor with dinosaurs and also have feathers mean that they likely both inherited feathers from said ancestor, meaning feathers might be much more ancient than we think.

Then we have the final issue that seems to be present in most dinosaurs/prehistoric animals in movies and it's something I've touched on in previous parts. Look at that scrawny neck! How could this thing even lift its head? Let alone swallow anything!. Could you even fit a windpipe in that neck when there is already vertebrae in there?

Hollywood, for the last time, dinosaurs and their relatives had much more than just skin covering them bones.

Actual depiction of the animal:

An artist's reconstruction of Pteranodon
Image credit:


Two ankylosaurs on the bank of a river
Image © Universal Pictures, image is fair use.

Ah, nature's tank. These big boys were absolute powerhouses and first appeared in Jurassic Park 3. To be fair, there isn't a huge amount you can get wrong with this dinosaur at a glance, since they didn't look too dissimilar in real life... there are still some issues...

Primarily, this dinosaur looks a little bit too squashed and bulky. I know these dinosaurs were extremely big and heavy, but they were slightly more elongated with ever so slightly slimmer legs. It wasn't by a lot, but still fairly noticeable. The neck was also slightly longer than what we see in the film, otherwise turning its head would have been fairly impossible with all that armour! The head also looked a bit more rounded and less 'beaky' (scientific term, I'm sure).

Speaking of armour, Ankylosaurs were famous for it. The armour of these dinosaurs were made up of something known as osteoderms. Osteoderms are lumps of bone that grow within the skin of an animal, most commonly seen in the armour of crocodiles. These things were incredibly durable and relatively lightweight, likely covered in keratin. They were also vascularised (so blood could travel through them), meaning they were likely handy for thermo-regulation like crocodiles. When we are talking about keratin coverings on dinosaurs, it is often hard to predict exactly what they looked like, so artistic license is often taken to make them look more 'spiky'. We don't think that Ankylosaurus had armour that looked quite as spiky as it is in Jurassic Park 3, however, it does bear some resemblance to another type of ankylosaur whose armour we know very well, mostly because it has been mummified. Nodosaurus textilis is a dinosaur whose armour has been almost completely preserved, spiky osteoderms and all!

A quick side note, while Nodosaurus didn't appear in any of the films, this dinosaur does feature in the Jurassic World: Evolution games and I can't find a thing inaccurate about it (not that they had much excuse).

Screenshot from Jurassic World evolution showing a nodosaurus standing in grass
Image credit:

Actual depiction of the animal (with added colour for speculation):

Artist's reconstruction of an ankylosaurus
Art belongs to Chris Masnaghetti


Here is another brief appearance in Jurassic Park 3, recognised mostly from the famous nose horn. Again, the glimpse is brief but we can see enough here. Looking past the 'JP hands', the most striking part of the Ceratosaurus we see is the bright red colour. While we have no evidence of Ceratosaurus nasicornis colouration, this is entirely plausible, especially for a male who may have used bright colours for display much like modern birds. Then there is the horn along with the skull shape.

The horn is a feature that gives Ceratosaurus nasicornis recognisability, which we can clearly see in the film. One thing missing, though (which was, again, fixed in the games) is another set of brow horns not too dissimilar from Allosaurus. The biggest inaccuracy of this dinosaur is most definitely its size. The dinosaur we see in Jurassic Park 3 isn't quite as big as a T.rex, but it's not far off. In reality, Ceratosaurus nasicornis was not much taller than the average fully grown man.

Actual depiction of the animal:

Size comparison of ceratosaurus
Image credit:

Like I said in previous parts, I'm going to break this post up into a few different posts. Keep an eye out, because next time we'll be looking at:






Until next time!

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