Science

This 130 Million Year Old Dinosaur Just Went Digital. Here’s How it Happened.

Over four days (and two nights) London’s Natural History Museum 3D-scanned every piece of its historic Mantellisaurus specimen. But what can you tell from a load of old bones?Tuesday, 20 August 2019

By Simon Ingram
Crowds swirl around the Mantellisaurus skeleton in Hintze Hall, the grand gallery of London's Natural History Museum. The dinosaur is one of the first specimens the museum's 5 million annual visitors see.

The day’s been busy at London’s Natural History Museum. It’s the summer holidays and Hintze Hall – the vaulted centrepiece of Kensington’s gothic-towered edifice – has been buzzing with curious life of all ages since early morning. But now it’s closing, and as the last of the day’s visitors are politely shooed out, the hall falls silent. But only for a minute. 

Soon the hall is echoing with the clatter of scaffolding, the wheeling in of plastic boxes and bubble wrap. A collection of pillows is brought in. Ladders, toolboxes. A group of men in safety boots, carrying instruction manuals and wearing frowns, are mingling with a few of the museum’s scientists and conservationists, emerging from the museum’s back corridors as the gallery empties. All converge on a case set in a niche just inside the museum’s entrance, containing the skeleton of a bipedal dinosaur that in life looks to have been the size of a rearing horse: Mantellisaurus atherfieldensisKnown to its friends here as Mantelli. 

Amongst the murmurs of logistics and the clink of tools, the words ‘pizza’ and ‘Red Bull’ are heard. It’s going to be a long night. The reason? Mantellisaurus is coming out of its case, going for a walk, then having a scan. And when you’re over a hundred million years old, that’s quite a big deal.     

Mantellisaurus peers out of its case into Hintze Hall – where ’Hope‘ the blue whale skeleton hangs on permanent display. The fossil was first discovered in 1914 and is 86% complete.

Between evening yoga sessions, sleepovers (‘Dinosnores’) and other events beneath the Natural History Museum’s diving skeleton of Hope the blue whale, Hintze Hall is rarely empty of the living – let alone its resident long dead. As work continues tonight a collection of lifeless eyes of striking diversity watch from all corners of this vast hall: whale and a mastodon in bone, Charles Darwin in marble, a marlin from a murky tank of goodness knows what, a collection of mounted birds from their stuffed perches. At close-quarters, the eyes of Mantellisaurus are the oldest of all: it’s been dead for 130 million years, since the early Cretaceous period. Our timescales are meaningless in such company, but to the humans present tonight, time is very much of the essence. 

More watching eyes: those of palaeontologist and researcher Dr Susannah Maidment, into whose care the disassembled bones will soon pass for scanning. “I’m not particularly worried, despite the anxiety dreams I’ve been having,” she says. “I think the biggest challenge is to get all the scanning done in the time we have available. Getting access for us to be able to do this has been really, really, really tough. We only have three days.” 

The Iconic British Dinosaur

This specimen was discovered in 1914 in the cliffs of the Isle of Wight by the amateur palaeontologist Reginald Walter Hooley. He named it atherfieldensis after the nearby village; it was named Mantellisaurus much later, in honour of Gideon Mantell – the pioneering anatomist who first discovered the famous creature that, originally, Hooley thought he’d found. 

The armature of the fossil dinosaur is subtly visible on display – and has been designed to allow easy assembly and reassembly.

Mantellisaurus used to be called Iguanodon,” says Maidment, “but Iguanodon is basically now like a waste basket taxon. Everything that came out of this Wealden Group of rocks – probably about 25-30 million years of depositional history – was just called Iguanodon. These are the kind of iconic British dinosaurs, but we now know there are probably six or seven different genera. And this is one.”      

Mantelli is special for two reasons. Firstly, the museum’s specimen is nearly 86 per cent complete, and is the holotype: the international go-to reference for its species. Secondly, what many of the crowds that gather gaping before dinosaur skeletons all over the world don’t realise is that many – or elements – of them are reproductions: painstaking models, essentially, crafted for display while the real bones are conserved elsewhere. But Mantelli isn’t: bar a few pieces, it’s the real deal. And while this is this is a treat for visitors, for scientists it poses a problem. 

“Because it’s in a glass case, we can’t study it,” Maidment continues. “We can’t find out anything about it. And because it’s the holotype, if we find a new specimen, we need to compare it to this one to find out if it’s the same thing. But we can’t, because,” she taps the case, “it’s in here.” 

If the studious activity of the engineers at the end of the case is evidence of anything, it’s that gaining access isn’t simply a matter of turning a key and swinging open a door. But access isn’t the only reason. “If you want to understand locomotion modelling, bite-force modelling, everything is now done computationally. And this is the first step to getting that data.”

An early view of Mantellisaurus, published in an 1893 book entitled Extinct Monsters by H N Hutchinson. It is now believed Mantellisaurus walked primarily on four legs.

So this is why Mantellisaurus is being scanned: to create a super-detailed, digital 3-D model of each bone that can be rotated, examined in detail, fed into computer software and – as an added logistical bonus – shared all around the world. “We don’t charge for researchers to access our collections, but they might not have the resources to travel to the UK to study them,” Maidment continues. “I can now share it internationally with anyone at the click of a mouse.”

After much consultation of manuals and the application of 'delicate force' with glass suckers, the case is opened – with not so much as a hiss of foetid air. A track is built and eventually, the dinosaur cranks gingerly out. Then the scaffold specialists set to work, building a trestle onto which the scientists can climb up and begin to deconstruct the skeleton, logging every piece, like a jigsaw. The night goes on. The light dims outside, the other denizens of Hintze Hall dip into shadow, floodlights are brought in, and the Mantellisaurus is the focus of a pool of light and activity. 

Opening the case: a delicate matter.
Susannah Maidment and Mark Graham peer into the open Mantellisaurus case.

Preservation vs Presentation

Fossil preparator Mark Graham is watching tonight disassembly with interest, if maybe a slight frown. It was Graham who oversaw Mantelli’s installation into its current case; prior to that it had been suspended from a ceiling in the dinosaur gallery. “When we put him in his case I thought he’d be in there for 50 years. Two years later, out he pops,” he says, before brightening. “But it’s good. The system works. It was built so it could be moved.”

Mounting and displaying real skeletons is a risky business: firstly, they can be fragile. Long bones such as femora often need to be held vertically and mounted delicately, as lateral handling can cause them to break under their own gravity. Then there are security concerns: the toes of ‘Dippy,’ the famous Diplodocus that once stood where we are now in Hintze Hall – and is currently touring the country – were rumoured to be sought after souvenirs at one point, despite actually being casts. Then you can never rule out legal action if a piece of towering skeleton falls off its perch onto an unsuspecting visitor. And this would hurt at the very least, because thanks to time, pressure, and the fossilisation process of mineralisation, it’s been a long time since these bones were bones: they are as heavy as rocks, because they arerocks. And finally, as if these weren’t reasons enough, it is rather challenging on every level to make a collection of rocks look like they were once alive. Despite the practical constraints, to start with there’s the question of how it stands.

“Originally it stood like a kangaroo, its tail dragging on the floor,” says Graham. “Then as research progressed, people realised it was bipedal but could go down on its forelegs, the tail was lifted, and this stance was adopted. We try to portray a sense of movement.”

One by one, the bones go into plastic boxes lined with pillows and bubble wrap. Everything comes off in meticulous order – “like a jigsaw”, says Maidment – and gradually, Mantellisaurus ceases to be a single entity, and becomes many. Ready for the next phase. 

In the public Marine Invertebrates Gallery, under the watchful eye of a giant squid model, the scanning takes place.

Making a Digital Dinosaur

Next morning, the action has moved to the museum’s cabinet-walled Marine Invertebrates Gallery, and it's hot. The room resembles a kind of strange field hospital, and is cordoned in two: half a curious mingle of visitors, half a bustle of scientists, portable fans and wires and glowing screens. Summer weather and school holiday crowds, compounded by the heat of laptops, lights, and two large 3D surface scanners means everything is overheating, not least the scientists – many of whom were up until 2am the previous night dismantling the skeleton. 

Mantelli is in here, too, and it’s everywhere: on the floor, on tables, under scanners and spotlights, in boxes, on floor mats covered in sticky notes, and in hands under curious eyes seizing the opportunity to study the specimen first hand. Close-quarters, the bones are fascinating. They’re heavy; again, they’re rocks now. Out of the metal armature, they look fragile and disparate, but they still look like bones. And more importantly, they still carry the physical signature. “Even though they aren’t bone any more they still carry the same morphological detail,” says Mark Graham. Although the damage of a hundred million years of mountain building, squashing and fossilisation weren’t the only challenges these bones have faced in less enlightened times of preservation. “This particular specimen, some of the bones have been damaged over the years as they’ve been suspended from the ceiling in the old dinosaur gallery. On wires,” Graham continues. “So the vibration of millions of visitors over the years… some of the joints have suffered.”

The objects which will record all of this history – recent and otherwise – stand in opposing corners of the room. The 3D surface scanners, futuristic glowing ray guns on articulated arms, projecting coloured lights being shone along bones. An adjacent screen gradually builds a green visualisation of the bone that refines with every sweep. 

PhD student Joe Bonsor uses a 3D scanner to digitise a thigh bone. Care must be taken to hit every surface, or the scan will be incomplete.

“3D models actually help us do lots of cool stuff,” says Susannah Maidment. “A lot of what we do is comparative anatomy. What do today’s things that have these features do? When we’re doing locomotion modelling, we’ll take these 3D scans, then dissect crocodiles and birds and look for the same muscle scars on the dinosaur. So we can then put it through software to make a leg swing and say well, this muscle pulled this leg forward, and it worked harder than this muscle in a different dinosaur. So what does that tell us about function, or running speed?” She says. “It’s very multidisciplinary. Biomechanics, histology, geology, medicine. People come in to palaeo with completely different skill sets.”  

One of these is Jeremy Lockwood, an ex-GP studying Mantelli for a PhD. Methodically measuring, calculating and drawing, his tools are a calliper ruler, a tape measure, an iPhone and a sketchbook. He holds up a humerus and runs his hand over section that looks like tree bark. “You see this roughness here, the deltopectoral crest – this means this thing must have had really powerful deltoid and pectoral muscles. So it’s interesting that it’s often seen as a bipedal dinosaur.” 

(Read: 'Astonishingly rich' dinosaur dig reveals its secrets.)

João Leite examines Mantelliosaurus hand bones. Close examination of the individual bones allows him to deduce aspects of the lifestyle of the dinosaur.

On a table under some lights a man in a Jurassic Park t-shirt is removing the bones of the Mantellisaurus forearms off its metal supports with precision scissors. In front of him is a variety of 3D printed models, scales, and a camera. His name is João Leite, and he too is studying for a PhD, his on dinosaur hands. These hands will be CT scanned also – to determine which of the bones are antique replicas, and which are real; weight and a learned eye can usually deduce it with bigger bones, but with smaller ones, it’s not so obvious. 

“Here in these animals, the wrists are all fused together,” he says. “Then the thumb is the famous thumb spike. It’s almost like they completely lost the finger, and are just left with the spike.” 

The thumb spike is the famous Iguanodon signature: one of the first fossils found by Gideon Mantell. The first palaeontologists didn’t know where to put it, so they put it on the nose thinking it was a horn. Nobody still really knows what it was for. “The small thumb spike is really hard,” Leite says. “With Iguanodon, people thought, maybe it was a defence against predators. But that’s kind of a weird one as the arms are not that long. If a predator is attacking from the front, you’re not going to think, ‘Rrrr, I’m going to stab you in the neck.’” He laughs. “It got pretty gory in old paintings. Nowadays researchers are more inclined to think that the thumb spike was used more for fighting between members of the same species, or to help dig out roots, crack fruits and tear tree bark.” 

Close examination of the Mantellisaurus hands show flattening of the digits, suggesting there were used for walking as well as grasping.

He indicates the longest fingers, and the flattening in the bones on the end: like miniature hooves. Then he imitates the stance with his own two forefingers, is if trying to press invisible buttons on the table. Here is clear evidence the dinosaur used its forefingers for walking. “Basically once you get all the bones individually and you can see all of their surfaces, you can try to figure out how the different bones articulate and moved relative to each other, how the animal used it’s hands to walk around, and what it did for a living.”

João breaks off to answer some questions from a member of the public, curiously leaning over the belt rail. There have been a few this morning: the work on Mantelli, warts n’ all, is being done in full view of a procession of museum visitors behind a belt barrier and a sign saying ‘Research in action.’ A similar sign stands in the now rather bare-looking case in Hintze Hall, where the now even more skeletal Mantellisaurus armature stands with only its non-removable pelvis, shoulder and skull remaining. Even these are attracting considerable interest: between this vacant case and the takeover of the marine invertebrates gallery, more reasons why this scanning project is very much on the clock. 

(Related: The desert-dwelling dinosaur that balanced on single toes.)

PhD student João Leite and Dr Susannah Maidment evaluate 3D scan data.

“A lot of what we do is comparative anatomy. What do today’s things that have these features do?”

Dr Susannah Maidment
The painstaking process of 3D scanning the dinosaur piece by piece requires each scan to be examined for quality and gaps in data.

The pelvis and a few other bones that couldn’t be removed were scanned last night in situ using portable hand scanners. Reflective dots pinned to the bones to helped the scanner reference its position, and build a map of the bone – like foundations off which to build a 3-D scaffold. In the gallery today most of the action is on the larger scanners.  

“Here we have a laser projecting a straight line onto the surface of the bone, and a camera looking at it from an offset angle,” explains Dr Amy Scott-Murray, the museum’s 3D Imaging Specialist. “When a laser is projected on a flat surface it looks perfectly straight. On a bumpy, curved surface, from the camera’s offset point of view, it looks bumpy and curved,” she says. Sensors in the arm let the camera know exactly where the camera is and what direction it’s pointing in as it moves around. “And it combines that information with the way the line changes shape as it moves across the surface to reconstruct its topography.”

Scanning continues for the next two days. Then on Thursday night, Mantelli goes back into its case. It’s another night shift, and it’s harder to put back together then take apart; Susannah Maidment tells me later the job was finally done by 2.30am. And the work is already revealing insights. “We noticed a few discrepancies between what people had previously said about Mantellisaurus and what we observed,” says Maidment. “So we decided that we will write a paper re-describing the holotype.”

view gallery

As for the future, it is evidently increasingly digital. “As a museum we have an ongoing aim to digitise all of our specimens, be that via photography, digital records, or 3D scans,” continues Maidment. “We’ll continue to scan specimens as and when the opportunity arises. But it might be a while before I’ll be allowed to take another dinosaur off display again. And I need to catch up on some sleep first.”

Old Storage 

While the Mantellisaurus begins its new life on hard drives as a digital entity, down in the museum’s basement is a more traditional kind of storage – and the final piece of this dinosaur’s jigsaw. Like the pelvis and the few other bones which couldn’t be removed, the skull remained in the display case. But unlike the other insitu bones, it wasn’t scanned. Because it isn’t real – it’s a facsimile. The real skull was scanned where it’s stored: down here in the basement. 

Here are corridors and cupboards containing racks and racks of meticulously catalogued specimens, collected over the museum’s life. Many historic, some famous, most too fragile to be displayed, projects like the Mantellisaurus scan means these specimens – and these corridors and lamp-lit desk – may become secondary reference points to the digital versions being created. It’ll certainly be less physical, in more ways than one. 

Professor Paul Barrett wrestles with a drawer marked ‘Heavy!’ onto the workdesk. Inside is four transparent boxes, each containing a fragment of bone. The drawer is then joined by another, similar tray. Then another. 

Fragments of the Mantellisaurus skull in the basement of the Natural History Museum.
The real Mantellisaurus jawbone, complete with teeth arranged in a 'dental battery.'

“Skulls are usually like this... It’s rare you get one that’s still in one lump.”

Professor Paul Barrett

You might expect to be presented with an object the size of a roast chicken, but Mantellisaurus’s skull is in many pieces. Some of the bones are little bigger than a peanut. And very few of them – a piece of jaw, say – are identifiable to untrained eyes as a bone fragment, never mind part of a skull. 

“Skulls are usually like this,” says Barrett. “It’s rare you get one that’s still in one lump. We actually have quite a lot of the bones here, enough to make a decent-looking skull.” In combination with complete skulls of related dinosaurs, “you can use those as a sort of template for working out how these different bones go together.”

It’s little short of wizardry that these bones can be reconstructed into the object now redisplayed in its case upstairs. Evidently, bone has “a woven or spongy texture,” as Barrett says. A particular feel, colour, a taste, even – and that once you get your eye in on a dig, it’s not that hard to separate it aesthetically from the rock it’s become a part of. See a specimen like the Mantellisaurus skull and it’s a difficult statement to process.

But with more people wherever they are able to study ancient bones in detail, the picture of the world back in the dim and distant past is getting more clearly defined every day.  

Mantellisaurus is now back on display in Hintze Hall. Like many other specimens, the skeleton has a new digital life and will be able to be accessed by researchers all over the world.
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