Like many children, I had a severe dinosaur phase. There was a period of my life when I cared more about prehistoric reptiles than pretty much anything else.

However, it turns out that much of what I thought I knew is wrong. That is because the prevailing image of dinosaurs has always been a little slow in catching up with current scientific understanding.

Until the "dinosaur renaissance" of the late 1960s, dinosaurs were always depicted as sluggish and lumbering. But experts realised that they had active lifestyles, and this slowly filtered through to the public – helped by 1993's Jurassic Park.

The past two decades have seen another major revolution in our ideas about dinosaurs, thanks to new fossils from China and advances in technology. But most of these findings have not seeped out into popular depictions of dinosaurs.

Here are some of the most famous dinosaurs, as scientists now think they were. It may seem a bit unfamiliar.

Velociraptor

Let's begin with an idea that many have heard of, even if they are unwilling to accept it: some dinosaurs had feathers. Not just a few feathers here and there, but full coverings of plumage.

As early as the 1980s, some palaeontologists were suggesting that dinosaurs possessed feathers. Increasingly, fossils of primitive dromaeosaurids – the family to which Velociraptor belongs – were found with full feathered wings. Yet depictions of this iconic predator remained fairly traditional.

Our first impression would be that they were just very unusual-looking birds

This all changed in 2007, when a US research team discovered "quill knobs" on the forearm bones of a Velociraptor fossil. These knobs are where wing feathers anchor, and provide conclusive evidence for winged, bird-like Velociraptors.

In fact, the dinosaurs immortalised as man-sized, pack-hunting monsters in Jurassic Park have been some of the most badly misrepresented.

"If animals like Velociraptor were alive today, our first impression would be that they were just very unusual-looking birds," says Mark Norell of the American Museum of Natural History, part of the quill knobs team. This is not just in reference to their feathers: the real Velociraptor was only about the size of a turkey.

Michael Crichton, author of the original Jurassic Park novel, modelled his "raptors" after the much larger Deinonychus. He seems to have intentionally misnamed them, apparently because he felt "Velociraptor" sounded more dramatic.

Archaeopteryx

Archaeopteryx is widely regarded as the "missing link" between dinosaurs and birds. This hallowed status means it has attracted a fair bit of attention, not all of it positive.

Even if Archaeopteryx is considered the earliest bird, that label is somewhat arbitrary

Accusations of forgery have dogged Archaeopteryx fossils for years, generally coming from people uncomfortable with such clear-cut evidence for evolution.

In fact, new research suggests that Archaeopteryx may not be a missing link after all, but not for the reasons promoted by anti-evolutionists.

Upon discovering a very Archaeopteryx-like dinosaur in China, researchers speculated that the famous bird ancestor may actually have been a predecessor of small, predatory dinosaurs like Velociraptor. This has since been contested.

Even if Archaeopteryx is considered the earliest bird, that label is somewhat arbitrary. "It's basically impossible to draw a line on the [evolutionary] tree between dinosaurs and birds," says Steve Brusatte of the University of Edinburgh in the UK, co-author of a 2014 paper exploring the evolution of early birds.

It seems there was no one missing link between birds and dinosaurs, just a gradual transition featuring lots and lots of feathery intermediates.

Triceratops

The eternal nemesis of Tyrannosaurus and of every parent who has had a plastic one embedded in their foot, Triceratops is one of the most beloved dinosaurs.

Even famous species can sometimes be reclassified

So in 2009, when John Scannella and John Horner published a paper suggesting that Triceratops was just a juvenile version of the larger, but less well-known, Torosaurus, there was uproar. The hashtag #TriceraFAIL was coined. People thought their favourite dinosaur was being consigned to the scrapheap.

That was not the case. Before long, various commentators pointed out that Triceratops had been discovered first, so if anything got the chop it would be Torosaurus.

Even so, this is a crucial lesson. Our knowledge of dinosaurs is often based on meagre fossil evidence, so even famous species can sometimes be reclassified.

Brontosaurus

Any true dinosaur aficionados will immediately recognise the mistake here.

In a family of enormous reptiles, Apatosaurus is just that little bit more enormous

Brontosaurus was the name given to the archetypal sauropod: a huge, lumbering plant-eater with a long neck. But for well over a century scientists, have been sure that this dinosaur never actually existed.

In fact, the skeleton first presented as Brontosaurus was an Apatosaurus, with a skull based on that of Camarosaurus.

However, in 2015 a research team revealed new analyses demonstrating significant differences between the original Brontosaurus and Apatosaurus fossils, suggesting that the Brontosaurus genus should be resurrected.

The key distinguishing factor, the team says, is size. In a family of enormous reptiles, Apatosaurus is just that little bit more enormous.

Tyrannosaurus rex

Some researchers are determined to emasculate Tyrannosaurus. Having spent decades fending off accusations that it was a lowly scavenger, rather than the ferocious hunter of popular imagination, now the "tyrant lizard" is facing another image crisis.

As the feathered revolution swept palaeontology, experts began to ponder the Tyrannosaurus genus. Surely the most charismatic predator of all time could not have been fluffy?

Would a feathery Tyrannosaurus have been less scary?

No plumage has so far been found on the 50-plus specimens of T. rex unearthed across North America. But there are some intriguing clues coming from China.

In 2004, a primitive tyrannosauroid was found with a covering of feathers similar to those found in other small, predatory dinosaurs.

This was followed by the the 2012 discovery of Yutyrannus – meaning "feathered tyrant". This giant predator was closely related to T. rex and not far off it in size. It was covered in long plumes.

These findings suggest a whole new look for the most famous predator of all time.

The question is, would a feathery Tyrannosaurus have been less scary than the roaring, lawyer-chomping monster we all know and love?

Stegosaurus

Experts have a proud history of coming up with wacky explanations for strange dinosaur features; explanations that tend to creep into the popular canon and stubbornly remain there.

For instance, a widely-circulated "fact" about Stegosaurus is that it possessed a supplementary brain in its pelvic cavity, to make up for the tiny one it its head.

Sex could have been the key driver for many of the most extravagant traits observed in dinosaurs

Stegosaurus was probably not the sharpest tool in the box, but that does not mean it needed a bonus brain. The enlarged cavity that inspired this myth probably housed a "glycogen body": a structure found in many birds, possibly involved in energy storage.

Then there are the plates on its back.

For some time, the most popular theory was that Stegosaurus's most prominent attributes were essentially "solar panels" to help it regulate its body temperature. But this has since been disputed. After all, if that is what the plates evolved for, why are the adornments of other stegosaurs more like spikes than panels?

The great variety seen in stegosaur spikes plays into another line of thinking. Much like the bright and varied plumage of tropical birds, maybe the plates helped these dinosaurs identify one another and pick mates.

Sex could have been the key driver for many of the most extravagant traits observed in dinosaurs. In recent years, everything from the long necks of sauropods to the frills of ceratopsians like Triceratops has been attributed to sexual selection.

Pachycephalosaurus

Though not part of the dinosaur A-team, Pachycephalosaurus is well-known among more discerning dino-fans for one thing: ramming heads.

Pachycephalosaurs could only head-butt once, and that trauma would have likely killed them

These dinosaurs are almost exclusively depicted engaged in combat, charging at one another head-first. Pachycephalosaurus had a dome-shaped head with a heavily-reinforced skull, and the dominant idea has been that males used these built-in battering rams to fight each other, rather like modern day bighorn sheep.

But some researchers have voiced doubts about whether Pachycephalosaurus could have engaged in such fights.

"[Our findings suggest] that pachycephalosaurs could only head-butt once, and that trauma would have likely killed them," says John Horner of Montana State University, USA, who co-authored an investigation into the microstructure of their skull tissue. He suggests that the domes could be another useful display structure for attracting mates.

Ankylosaurus

Covered from head to tail in thick armour plates, Ankylosaurus was the medieval knight of the Cretaceous period.

The armour was thereby endowed with great strength in all directions

Modern palaeontologists employ technology to wring ever more detailed information from fossils. This was demonstrated in 2004 by Torsten Scheyer at the University of Bonn, Germany, who used polarisation microscopy to uncover remarkable new layers of complexity in Ankylosaurus armour.

Far from being the oversized scales that experts had previously envisaged, the armour turned out to have a complex microstructure of bone and collagen, analogous to the structure of fibreglass or Kevlar.

"The armour was thereby endowed with great strength in all directions," says Scheyer. It would also have been surprisingly lightweight. "Today's composite materials, which are used to make the rotor blades for wind farms or bullet-proof vests, are based on the same principle."

It seems the Ankylosaurus was less a clunking medieval knight, more a modern super-soldier.

Spinosaurus

Another dinosaur made famous by a Jurassic Park movie, Spinosaurus was shown engaging in an epic showdown with Tyrannosaurus, with predictably riotous results.

Working on this animal was like studying an alien from outer space

You can see why the film-makers chose Spinosaurus. At 50 feet (15.2m) long, it was 9 feet (2.7m) longer than Tyrannosaurus. It also possessed long, menacing jaws, and a freaky "sail" jutting out of its back.

Spinosaurus has always been a mystery, known only from skeletal fragments unearthed in the deserts of North Africa. Then, in 2014, a team led by Nizar Ibrahim of the University of Chicago in Illinois, USA, announced that they had discovered new remains. These fossils seem to confirm something long suspected: Spinosaurus is the only known aquatic dinosaur.

Ibrahim's analysis suggested a creature with small hind limbs more suited to swimming than hunting on land. It also had a long, crocodilian snout, and bone microstructure similar to that of other aquatic vertebrates.

"Working on this animal was like studying an alien from outer space," says Ibrahim. "It's unlike any other dinosaur I have ever seen."

Bonus: Pterosaurs

This one does not quite count, because pterosaurs were not actually dinosaurs: a fact that gets overlooked from time to time.

Some members of this group stood as tall as giraffes

For many people, the name "pterodactyl" is the most familiar. But this only refers to one of the many groups of flying reptiles, which are collectively called "pterosaurs". The group was actually enormously diverse.

At one end of the spectrum you have Nemicolopterus, a tiny pterosaur with a wingspan of only 25cm (10 inches).

Then there are the big boys: the azhdarchids. When crouched on the ground, some members of this group stood as tall as giraffes. When they stretched out their wings, their span would have been a whopping 10m (32.8 feet). By some distance, they were the largest flying animals of all time.

And yet, the most popular recent depiction of these giants, illustrated above, is as terrestrial foragers, occupying a similar niche to modern-day storks.