I'm a dinosaur expert - this is what Hollywood always gets wrong

When most people picture Tyrannosaurus rex, the chances are they imagine a towering, lipless predator, teeth bared in a permanent snarl - the terrifying monster which has stalked across cinema screens for the past three decades. But according to palaeontologist and artist Mark Witton, that image is as outdated as a VHS tape.

Mr Witton, who will be appearing at New Scientist Live next month, explains: "The face, in particular, should be very different, with the teeth covered by scaly, lizard-like lips. "Compelling evidence has long suggested that predatory dinosaur teeth were hidden behind lips, but artistic conventions - the rule of cool - have perpetuated and standardised toothy, lipless interpretations in pop culture." That revelation alone would shock most casual dinosaur fans. But Mr Witton insists it is just one example of how Hollywood has warped public understanding of these animals.

He says: "The template for Hollywood's Tyrannosaurus was established by 1993's Jurassic Park, which was fairly accurate at the time, but it is now increasingly dated.

"Their constant roaring and snarling, for instance, is a stereotype that film and TV producers refuse to abandon, even when consultants emphasise that there are alternative, and possibly more realistic, ways to show dinosaurs vocalising."

Mr Witton has made a career of bringing prehistoric life to audiences through both science and art. His work has been featured in museums, books, even on stamps and coins. But he is adamant that accuracy must always come first.

Mr Witton says: "A featherless, lipless predatory dinosaur is a poor representation of Velociraptor in the same way that a picture of a spotted big cat is a poor representation of a tiger.

"It is not the job of palaeoartists to choose what to embellish or change for the sake of public interest, but to find ways to make the reality of the ancient world engaging.

"If an artist cannot find a way to make an eight-tonne predatory dinosaur or a flying reptile with a 10-metre wingspan interesting, they are doing something wrong."

Another misconception comes from how people project mammalian behaviour onto dinosaurs. Mr Witton explains: "We tend to view dinosaurs from a very mammalian perspective because we live in a mammal-dominated world, and are mammals ourselves.

"We think it is normal to look after offspring for extended periods, for instance, and for landscapes to be filled with fast-growing, mature animals. But dinosaurs may not have been like this."

Bonebeds and trackways suggest that young dinosaurs did not stay with their parents for long. In fact, juveniles may have lived entirely separate lives. Mr Witton says: "Baby and juvenile tyrannosaurs were long-legged, shallow-jawed and relatively long-armed.

"They probably had a different ecology to their older, bigger, and more robust parents. Dinosaur ecosystems would have been filled with partly grown animals operating as separate 'ecological species' to their parents, totally unlike wild landscapes in modern times."

That difference - ecosystems built not just around adults but around animals of every growth stage - is one of the most surprising insights to emerge in recent years. It fundamentally challenges how life in the Mesozoic is imagined.

For anyone hoping for a single discovery to upend everything known about dinosaurs, Mr Witton advises caution. He says: "Dinosaur science is now pretty robust and mature, such that few ideas outside of niche, academic discourse stand to be completely overturned.

"The days when the entire discipline could be flipped on its head by a new fossil are over."

That does not mean the field is stale - far from it. New data is emerging that lets scientists probe areas once thought unknowable - such as dinosaur colour.

Mr Witton explains: "We now have data about dinosaur colour, a topic many of us - including myself - grew up thinking was beyond our grasp.

"Colour can give us insights into many facets of animal lives, from appearance to behaviour to habitat preferences, so these discoveries have fantastic implications for our understanding of the group."

The challenge now is knowing how far the evidence can be pushed. Mr Witton explains: "The next decade is going to find the proverbial edges of this avenue of research: what can we reliably infer about dinosaur lives and appearance from their colour data, and what is wishful thinking?"

Hollywood has also flirted with the idea of hyper-intelligent dinosaurs - think of Jurassic Park's cunning Velociraptors for example. Could that have happened if the asteroid had not wiped them out 66 million years ago?

Mr Witton says: "Crows and parrots - which are, of course, types of modern dinosaurs - are incredibly smart animals, so we know that dinosaurs can develop great intelligence. But a lot happened to the shape of dinosaurian brains en route to developing birds.

"The traits associated with high intelligence in birds and mammals have yet to be found in a reptile brain. It is far from a given that non-bird dinosaurs would have developed super-smarts had they not gone extinct."

That said, dinosaurs may already have been smarter than they have often been credited for. Mr Witton explains: "It is emerging that reptiles, for instance, are much smarter than we realised - capable of learning, playing, problem-solving, and remembering information long-term.

"We can be confident that dinosaur intelligence was not at a level where they could invent iPads or build skyscrapers, but they may have been much smarter animals than we have given them credit for."

Ultimately, Mr Witton believes that the fossil record itself provides more than enough wonder without Hollywood-style exaggerations.

Dinosaurs did not need to roar like lions or stalk the screen with permanent, menacing grins. They were real animals - stranger, subtler, and often more fascinating than the movie monsters many grew up with.

Mr Witton says: "The fossil record is full of so many awesome, wonderful species that, in the hands of a competent artist, they do not need embellishment."

And the familiar image of T. rex as a lipless, roaring giant may be one more Hollywood myth ready for extinction.

Mark Witton will deliver his talk, King tyrant: A natural history of Tyrannosaurus rex, at New Scientist Live at London ExCel on October 19 between 11.55am and 12.45pm.