Errors in the Movie "Jurassic Park"
Bennington, J Bret, 1996. Errors in the movie Jurassic Park. American Paleontologist 4(2):4-7.
The following is a edited listing of comments received over the internet in response to a request for scientific inaccuracies in the depiction of dinosaurs in the movie "Jurassic Park". This request was made at the behest of teachers at Memorial Jr. High School in Valley Stream, New York who wished to use the film to stimulate discussion of dinosaurs and what paleontologists do and do not know about them. Comments are organized by topic in the list below and individual comments are not attributed. The final topic is called "Commentary" and includes several more extensive discussions of the movie and the criticism it generated. The authors of these longer comments are identified.
I would like to thank everyone who responded to my initial request
for information. The teachers at Memorial Jr. High were astounded
to discover that people from all around the globe were interested
in helping them with their project. I would also like to thank
the managers of both the Paleonet and Dinosaur listservers, both
of which accommodated the brunt of the discussion. I also thank
Paul Willis for his generous contribution of an extended critical
essay on the subject of the scientific accuracy of "Jurassic Park."
The routines of palaeontology are presented incorrectly in the
movie right from the start. There they are, brushing the dirt
away from a complete, articulated skeleton of Velociraptor. If only it were this easy to dig up dinosaurs! I have never
seen an excavation where dirt is simply brushed away from the
fossils. Usually the entombing sediment has consolidated into
rock that has to be chiseled, hammered or even blown apart. Even
in the exceptional circumstances where the sediment is not consolidated
to rock (and these are usually fossil sites much younger than
any site likely to contain dinosaurs), the sediment still has
to be patiently loosened using screwdrivers or awls. So the fieldwork
of a palaeontologist is portrayed as being far easier than a real
dig. What is left out is also telling; finding fossils by simply
walking around, looking at the ground, forms 95% of the fieldwork
of a palaeontologist but, obviously, this would be a little hard
to portray in a movie.
They use a shotgun seismic source, and then as the image of the
skeleton becomes resolved, the operator refers to "ground penetrating
radar"! Then there is the near-impossible resolution (from a single
The microscope in the trailer at the beginning of the film is
set up backwards! Ralph Salomon, a nannofossil specialist here
at Amoco in Houston, received a gift from Zeiss after informing
them of the mistake.
The amber from which the dino DNA was extracted in the movie came
from the Dominican Republic. But Dominican Republic amber is all
Late Eocene at the very earliest; no dinosaurs are going to be
cloned from that source. In a real Dominican Republic amber mine,
you can't stand upright; the shafts are so narrow the miners have
Paleobiological Errors (or controversies)
Eucalyptus and other modern plants such as grasses would not be
especially good for dinosaurs to eat. This idea is based on the
assorted toxins which discourage modern herbivores. Koalas manage
by eating a little of several different species of Eucalyptus
and still are probably somewhat drugged by their diet. It seems
unlikely that brachiosaurs would have adaptations to deal with
plant toxins which evolved in the Cretaceous or Cenozoic. Grasses
are generally high in cellulose and silica, and diversified relatively
recently. Perhaps the Triceratops was ill from trying to digest
In at least one scene in the movie the paleobotanist notes the
presence of a formerly extinct plant species from the Mesozoic
Era growing on the island. Obviously, plants cannot be cloned
from mosquito blood, yet no explanation is given for how extinct
flora was ressurected.
The bit about the brachiosaurs "chewing like a cow" was also obviously
wrong. They just raked the vegetation and swallowed. It is unlikely
their peg-like teeth could chew significantly.
The Brachiosaurus had too large a head, probably could not stand
up on hind legs only (was too front-heavy; other sauropods could
rear up for feeding or defense with more ease), sneezing is also
doubtful, because this diaphragm reflex is typically mammalian
(dinosaurs did not have rib-less belly separated by the diaphragm
from the ribcage containing lungs).
The movie showed the brachiosaur chewing by moving its jaws from
side to side, like a cow or horse chews. Dinosaurs couldn't do
that--their jaws moved just up and down, so they had to find other
ways to grind vegetal matter (gizzard stones and swing-out upper
jaws, for example).
Earlier on, the brachiosaur reared up on its hind legs to bite
off some branches from the top of a tree, but rearing up didn't
make its head any higher at all. So why did it rear up?
Lunch for the Jurassic Park Brachiosaurus was a good old Aussie
Gum Tree. This scene was shot in Hawaii where, like so many other
places around the world, gum trees have been introduced as a fast-growing
source of timber. What is the problem with Brachiosaurus chowing
down on an Aussie lunch? Gum trees are extremely poisonous and
the varieties of poisons carried by gum trees were not in existence
when Brachiosaurus walked the Earth. It is therefore likely that
Brachiosaurus would not have the immunity to these toxins (as
have been evolved in Koalas and other eucalyptus munchers) and,
if it didn't spit out its first mouthful because of its bitter
taste, it would probably drop dead very quickly after its ingestion.
The Dilophosaurus was probably not endowed with neck frill (borrowed
from Australian frilled lizard) nor could spit venomous saliva
(though its bite could have been poisonous due to bacteria developing
in rotting meat in theropoddental serrations; bacterial toxins
help the Komodo dragon in killing their prey).
If Dilophosaurus did have a frill, we would know about it. There would be fossil
evidence of bones or some other rigid structure required to hold
the frill up and there would be markings on the bones of the neck
indicating where muscles could attach that would be required to
move the frill up and down. We don't see either of these.
Dilophosaurus was too small.
If Dilophosaurus indeed had an expandable skin collar around its
neck (and that's total speculation), it certainly wouldn't have
deployed it when facing a prospective meal (Nedry). That kind
of display is more for intimidating prospective competitors (such
as for mates or territory). Why would a carnivore try to intimidate
its next meal?
One little side note - When Nedry and the Dilophosaurus are studying
each other, Nedry pulls the hood of his raincoat over his head,
which may parallel the hood-flaring of the Dilophosaurus and trigger
an intimidation response. Or maybe I just have too much time on
The Velociraptor was too big (rather Deinonychus-sized), and too
The breath expelled through the nostrils of one of the Velociraptors
fogged the window in the door to the kitchen. This implies both
a moistening of inspired air while in the respiratory system as
well as a body temperature elevated well above that of the ambient
environment - both traits associated with endothermic (warm blooded)
Velociraptor would not likely jump on a T. rex (as in the visitor
center at the end of the movie), any more than a cat might jump
on the back of a wolf--for any reason.
During high-excitement moments, the 'raptors' and the T rex both
ripple their tails and lash them, rather like a cat that's highly
annoyed. Therapods, however, have rigid fibers reinforcing the
vertebrae in the spine to help counter-balance the weight of the
animal. This would make tails much too stiff for thrashing. (the
reason they did it that way--Hollywood stop-motion dinosaurs have
always rippled their tails. It's a tradition that people seem
to expect from their dinosaurs).
The 'raptors' snarled several times, and even lifted their lips
in a snarl when angry. Theropods didn't have a lot of face muscles
and this is actually a very sophisticated movement in a human,
taking an extremely complex series of muscle movements that there
is no evidence of dromasaurids being able to do.
The Tyrannosaurus' vision was rather more bird-like than frog-like,
thus the idea that it could see only moving objects was only necessary
to allow the people to escape from sure death in close contact
with the T. rex (and perhaps a heritage from the frog DNA used
in the JP genetic lab).
When the T rex is chasing the jeep, watch his knees. They wobble
like someone doing the Charleston. If a real animal that stood
30 ft high, and weighed in the area of 9 tons ran like that, the
creature would dislocate it's own knees with each step of a run.
There's a LOT of force in a 9 ton animal's leg.(the reason they
did it that way--The animation tool that ILM was using for animating
in a computer environment, Softimage, had no way to simulate ball-and-socket-type
joints, such as the hip, so the animators faked one out of a hinge-type
joint as a poor substitute).
R. McNeill Alexander has argued previously that T. rex's leg bones
were neither thick enough or strong enough to support a full grown
animal running faster than 18 mph. Recently, James Farlow has
argued that running at high speed (such as would be required to
chase a jeep) would put T. rex at great risk of mortal injury
if it fell. This arguement is based on the physics of falling
at 45 mph -- the head dropping 11 feet to the ground and decelerating
on impact with a force of 16 g.
The T. rex always sounded like it was running on pile drivers.
Any potential prey within miles would have beaten a hasty retreat
at the sound of those booming footfalls. Also, tyrannosaurs had
springy, flexible ankles, which would have made it very difficult,
if not indeed impossible, for a T. rex to make that much noise,
even if it wanted to.
The Triceratops dung was of course much too big, compared to any
known coproliths and any possible rectal diameter of a dinosaur.
It appears that one of the favorite scenes for most children is
where the female palaeontologist starts raking through the mound
of Triceratops poo. Here comes my favorite mistake in the whole movie. The poo
piles appear to reach heights of around 2 metres yet the anus
of Triceratops would be around one metre above the ground. How did it get the
poo to the top of the pile?
The Triceratops had "fossil" horns! Somehow I don't think the
horns of a living Triceratops would be full of angular, "post-fossilization"
Most dinosaurs in the Jurassic Park were not Jurassic, but Cretaceous.
Check the spelling of the dinosaur names (Hint, Check out the
tubes holding the frozen genetic material).
They spell "Stegosaurus" incorrectly in the Embryo Storage Room.
DNA - Cloning Errors
Frog DNA would be an exceedingly poor choice for use as a template
for dino cloning (even if that were possible). Frogs aren't particularly
close relatives of dinosaurs. Leaving aside the obvious choice
of bird DNA (Yes Virginia, phylogenetically-speaking birds are
dinosaurs), there is a closer link between human DNA and dino
DNA than there is between that of frogs and dinos. One suspects,
that the archetypal image of "reptiles" as "lower" vertebrates
demanded that dino DNA be hybridized with the DNA of another "lower"
The movie-clip showed a scientist drilling into the amber, inserting
a needle, and WITHDRAWING FLUIDS. Fluids? After 65 million years?
Come on, now. The real scientists that do this type of research
are at the University of California at Berkeley. They take scrapings
of the material, and do much preparation in order to make the
fluid that they can then test for DNA.
Even having successfully cloned a dinosaur and produced an egg,
how does one get fully grown dinosaurs to grow up within the 3
year time frame of the story? Would it not take ten years, maybe
fifty years to grow a full size Brachiosaurus?
Although amber preserves insects in exquisite detail, it does
not preserve the animal (and its gut contents) in perfect order.
Usually all that is left inside the insect is a series of carbon
films that may preserve the major structures inside the animal.
Having said this, DNA fragments have been retrieved from insects
preserved in amber from the Mesozoic. But the fragments retrieved
so far are woefully incomplete. The best is two fragments of DNA
from a Cretaceous weevil. One fragment is 312 base pairs long
and the other is 226 base pairs long. The complete compliment
of DNA for that weevil would be between 1 and 10 billion base pairs long. And this is DNA of the insect itself, not what
it had been feeding on. There are a number of laboratories around
the world today that are looking for fragments of dinosaur DNA,
but not so that they can recreate dinosaurs. If fragments of dino
DNA are found, they can be compared to the DNA of other animals
to determine their relationships. It is a similar process to DNA
fingerprinting in criminal cases but, instead of focusing on the
differences between DNA fragments, palaeontologists would be interested
in the degree of similarity between different DNA fragments which
should be a measure of the degree of relatedness between the original
owners of the DNA. Although some hopeful finds have been made,
as yet no one has found indisputable dino DNA.
While we understand that DNA is the blueprint of an animals, and
while we have learned how to read pieces of that blueprint, we
do not know how to take a sample of DNA and turn it into an animal.
While we do have some techniques that work for reproducing short
sections of animals DNA and we can even 'create' new animals by
manipulating the DNA sequences available to us, we do not have
the technology to build a desired DNA sequence from scratch then
translate that raw DNA into a living animal.
During the "explanation" of chaos, the mathematician's watch jumps
ahead a few hours.
We see Dr Grant encounter a sheer concrete wall a couple of tens
of metres high. Only moments earlier we saw the Tyrannosaurus simply step over this drop as if it were flat land.
It's rather fun and (at least sometimes) illuminating to go fault-finding in Jurassic Park, but maybe we should be more bashful in our Crichton/Spielberg-bashing. The team behind the movie have made a better effort to get things "right" than most makers of science-fiction movies, so let's grant them the right to add some details for effect as long as it's not too flagrant or ridiculous.
` Adding venom to Dilophosaurus seems no less allowable than adding color to its skin, which you must do to make it look alive even though we know nothing about its real color. And, yes, it might have been "better" to use birds or even humans rather than frogs for the complementary DNA, but there was a purpose to the frog, namely to introduce propensity for hermaphroditism. If we can swallow the necessary but preposterous precondition of amber-begets-DNA-begets-dinosaur, we should be able to swallow that the choice of the frog was not based on phylogenetic proximity. And as for the proper time designation, would a more accurate title, like "Mesozoic Park", have made such an impact?
Some of the alleged errors are no worse than the delightful little joke when Velociraptor stalked beneath a metal grid and the light that sieved through spelt out the letters ACCGGATTCC... etc. on its skin. Light doesn't behave that way, but we don't care just now.
So let's allow the moviemakers some freedom with the details, particularly with regard to such cases where paleontologists don't have a full answer either, like the nature of Tyrannosaurus' vision, the maximum size of Velociraptor, etc. (I agree, though, the cow-like aspects of Brachiosaurus were unbecoming, and the dung heap was way-way oversized.) They have used science as framework and inspiration, and rather than pointing out that this little nut should be there instead and that little bolt was a wee bit smaller, we should use the limelight they have provided to bring our thoughts across on the whole thing. We should point out how palaeontology is the basis for their spectacular reconstructions, that some aspects of the reconstructions are well supported whereas others are more or less guesswork, but that every scientific interpretation needs to be tested and retested against new evidence, and, of course, that in order to do so we need to keep the science alive and evolving and wouldn't it be lovely if we could have some more money for field work in Mongolia?
I guess, though, that Bennington's kids might prefer finding plain
errors in the movie. No big problem, just as long as they remember
that there are errors and ERRORS and that even well-established
TRVTHS occasionally turn out to be errors.
I think Jurassic Park is simply a wonderful movie, and I would never consider participating in its deconstruction. I read the book at field camp. I saw the movie more than once on the big screen, and I bought a videotape as soon as one was available. I think the principal weakness of the film was not with frog DNA or backward microscopes or even with its unrealistic presentation of seismic imaging but rather with the way it portrays scientists and their work. Since the original inquiry to PaleoNet was for ideas that could lead to discussion among younger students, let me suggest that conveying to these students who scientists are and the ways in which they work is quite an important topic for discussion.
Present in Jurassic Park are all the principal stereotypes that have haunted science from the beginning: the bungling hero who probably couldn't plug in a desk lamp on his own (where is Fred McMurry when we really need him?); the oblivious and amorphous chaps in white coats cranking out monsters because it can be done with no thought to the trouble they might be causing (shades of Dr. Frankenstein); the mad scientists (one benign and one--the computer bloke--inherently evil); and, yes, the practical, khaki-clad, great-white-hunter type--a real-world kind of guy--who, in Jungle Jim fashion, sees the problem but is powerless to stop what others view as progress.
I know a few paleobotanists. None is also a skilled veterinarian
tooled up to snuff out heartburn among Triceratops. I know a few
mathematicians. None is quite as obnoxious or as single-minded
as Jeff Goldblum's 'chaosologist'. (The flick would have been
better if he had been the one in the outhouse.) I know a few bungling
scientists. None wears his clutzhood as a badge of honor. I hope
the younger students who discuss the scientific shortcomings of
Jurassic Park can come away from their experience with an understanding
that in the world of the 1990s scientists are just people, and
lots of people are scientists. After all, every last one of us
has at least one, real scientist living right in our own neighborhood!
-Roger L. Kaesler
At the beginning, before going to the Park, the paleontologist
made statements about dinosaurs he had no way of knowing (since
they were behavioral statements of sort which could leave no fossil
correlates). This is a fundamental *procedural* error with respect
to science, since science is a method based on using observations
to develop and establish results. Bret, if you can teach the students
to ask the question "how would he know that" of anything they
hear attributed to a scientist, you will be doing the world a
I think deconstructing cultural items like Jurassic Park is a valuable exercise for both professional paleontologists and for high school students. Jurassic Park was a movie carefully designed to entertain, not a documentary whose primary purpose was to inform. Yes, Crichton, Speilberg & Co. made some efforts to be accurate, but the errors we've already listed demonstrate that this sentiment wasn't allowed to get in the way of the director's and producer's vision. I too was very bothered by the way paleontologists were portrayed in the film; as stereotypic nerdish, computer illiterate people focused on their own research to the exclusion of everything else in life, willing to use their knowledge to score cheap points in arguments with little kids, and (most distressingly) willing to do almost anything (e.g., break camp and follow complete strangers to the ends of the earth to provide obviously bogus commercial endorsements) so long as someone waves a fistful of dollar bills in our face. Not a very complimentary image. Then again, Jurassic Park seemed to me to be a special effects movie, pure and simple. As one newspaper reviewer put it, the plot (of the movie, not the book) can be summed up in a single line; "attractive people running away from hungry animals." Given that the emphasis was on the dinos (as opposed to character development or plot) from the start, "nit-picking" the movie can provide important information as to how dinosaurs are seen by the general public.
For example, the gratuitous increase in size of the Velociraptors was used (by the production team's own admission) to make them appear more "sinister." Personally, I feel that even a single normal-sized Velociraptor (much less a pair, much less a group) would be a pretty formidable animal. I don't buy the idea that the Velociraptors needed to be scaled up in this way for the purpose of the plot. The production team had lots of expert advice on this movie (e.g., Jack Horner) and they did make some changes. I read that they tried to film the sequence of the Tyrannosaurus using his tongue in the Land Rover attack, but the tongue just looked silly on film. Even more interestingly, I understand that The movie team originally gave the Velociraptors forked tongues (Crichton makes no explicit mention of tongue shape in the book), but deleted them when Jack pointed out that there is no evidence for the presence of Jacobson's organs in any dino skull. It is interesting to ponder why the moviemakers felt the forked tongues were an inaccuracy they could afford to correct, whereas the gross exaggeration of Velociraptor size was deemed indispensable. As paleontologists, we are the ones who provide society with much of its image of the past. Critical looks at movies like Jurassic Park provide us with important feedback as to how the culture is responding to the images we
To move the conversation along on a different tack, I'd also like
to pick up on Rich Lane's question of whether Jurassic Park was
a net plus or minus for paleontology. It certainly did wonders
for museum attendance. On the other hand, paleontology is more
than dinosaur studies. Even though a paleobotanist figured prominently
in the book and the movie, I haven't detected any change in the
public's awareness of paleobotany. My guess is that once you get
away from the money made on commercial spin-offs from the movie
(very little of which found it's way back into our coffers), Jurassic
Park was pretty much irrelevant. However, there is a new book
(The Lost World) and a new Speilberg movie in pre-production.
Perhaps what we need to discuss is how we can do a better job
promoting paleontology and reaping some tangible benefits during
the second coming of the Hollywood dinosaurs.
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