Resurrecting dinosaurs with medical scanners and 3D printers

CT scans and 3D printers are making it possible to see fossils that were previously inaccessible inside rock.

Accurate copies of fossilised bones can now be made from the combined use of computed tomography (CT) scans and 3D printers, according to a paper published in the journal Radiology.

The technique offers scientists a non-destructive way of transporting and handling rare or fragile fossils.

To protect such specimens from damage during transportation, the fossils are often stored in plaster jackets or casts. These jackets must be strong enough to protect the fossils, but should also separate easily from the specimen when removed.

It is during the removal of the plaster and surrounding sediment that the fossil is in danger of material loss or even destruction. This typically occurs when the plaster is stuck fast to the bone.

(A 3D print of a fossil (right) next to the original still inside a plaster jacket. Image: Courtesy of Radiology and RSNA)

A group of German researchers found that, by using CT and 3D printers, they could separate fossilised bone from its surrounding sediment matrix in a way that would not harm the specimen, then produce a 3D copy of it.

Applying this method to an unidentified fossil from the Museum für Naturkunde in Berlin, the researchers scanned the bone with a 320-slice multi-detector system to show up the different attenuation (absorption of radiation) through the bone and the surrounding sediment matrix, depicting clearly the fossilised vertebra.

The scan also provided information on the condition and integrity of the specimen, like otherwise unknown fractures, and helped the researchers build an accurate reconstruction of the fossil.

Then using a laser sintering system – a process which uses high-powered lasers to fuse materials by adding thin horizontal layers of plastic – an accurate 3D copy of the fossil was produced.

(An enlarged 3D copy of a 380 million year old coelacanth skull found near Fitzroy Crossing, Western Australia. Image: John Long)

The impact on palaeontology
According to Richard Brian Gunderman, a professor of radiology at Indiana University who was not involved in the study, CT scanners are able to determine the exact structural dimensions of an object, down to fractions of a millimetre.

This data can then be used to construct a replica so precise that objects of great historical interest, like Stradivarius violins, have been created to sound remarkably similar to the originals.

“Such a technology has been a boon to palaeontologists in the past few years,” said John Long, strategic professor in palaeontology at Flinders University.

“Once we relied on meticulous time-consuming methods to prepare delicate fossils out of the rock and, even then, we could only see their external features. Now, using high-resolution micro-CT scanners and synchrotrons [particle accelerators], we can investigate every nook and cranny of the fossil right down to individual cells and tissue structures without having to risk damaging the specimen.

“Combined with advanced 3D printing, we can now slice though the ancient fossil skulls and print them in halves showing the full anatomy in clear definition. This will no doubt revitalise palaeontology.”

(A 3D scan of a 380 million-year-old Gogonasus fish skull by Tim Senden and ANU Vizlab.)

Ahi Sema Issever, from the Charité Campus Mitte in Berlin and one of the study’s authors, explained: “The most important benefit of this method is that it is non-destructive so the risk of harming the fossil is minimal. In addition, not only does this method allow for a global exchange of rare fossils in any quantity, data on the specimens can also be digitally shared between research institutes, museums and schools while protecting the original fossil.”

Darren Curnoe, associate professor at the University of New South Wales, agreed, saying: “Famous fossils like the Taung Child in South Africa - the very first ancient ape-like creature found in our human evolutionary tree - has been quite badly damaged following almost 90 years of study by scientists.

“Almost everyone who sees the fossil wants to take a couple of measurements of their own, and by doing so, is damaging these priceless pieces of our collective heritage. We need to do better, and such technology might just be the answer.”

A note of caution
Although supportive of the technological breakthrough in this study, Professor Long warned that researchers must not rely too heavily on tomographic imagery and 3D printing to draw their conclusions.

“It is important to carefully study the preservational biases of the original fossil first to determine how reliable a computer-generated image will be. In some cases, replacement of bone by other minerals or the presence of solid inclusions can effect the quality of CT images and affect 3D printing results.

“Scientists still need to study the original specimens in detail first, and then make interpretations using CT tomography and 3D printing.”

(A scanned 400 million-year-old placoderm eye capsule found in Taemas near Canberra. Image: Tim Senden)

Associate Professor Curnoe agreed, saying: “Any model made from CT scans must properly distinguish actual bone from missing bone, or even from materials like plaster, that had been used in the past to reconstruct missing bones in the fossils. This is particularly important since most fossils found are incomplete or distorted.

“In the end, there is nothing like seeing the real thing to fully understand the anatomy and the state of preservation of a fossil. But, for the sort of work many scientists do, especially postgraduate students, 3D models would be incredibly useful at a time when funding can be very hard to get.”

Beyond fossils
Some experts speculate that the findings from this study will benefit the medical field, like building and fitting implants in orthopaedic surgery. Others feel that the technique could be used to model real bones and other tissues, such as cadavers that have been preserved in ice or peat bogs.

Martin Baumers, a research fellow at the University of Nottingham, would like to see the implementation of a virtual library and data infrastructure for such 3D data and designs. He believes that it would aid collaborative research, allowing experts from different disciplines to share and retrieve 3D models for 3D printing or other scientific, even commercial, usage.

For Professor Long, the biggest breakthrough will come when palaeontologists possess the ability to make portable machines to take into the field and scan fossils, still buried under the rock layers, to determine the full extent of the fossil before excavating it.

This article was originally published at The Conversation. Read the original article.The Conversation

A scan of a 380million-year-old tooth from a fossil shark. (Image: Tim Sendon)
Sam Pepper via YouTube
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The story of Sam Pepper: how a British YouTuber incurred the wrath of the internet

The Dapper Laughs of online pranks  has finally gone too far.

Last night, a Twitter user claiming to be "a voice" for hacker collective Anonymous sent out a series of angry tweets slamming a video featuring "violent abuse". The user wasn't referring to Isis, which is the subject of an ongoing campaign by the hacker group, but a young, turquoise-haired British man named Sam Pepper. 

Pepper is a YouTube star who came to fame after appearing in the 11th series of reality show Big Brother. He's known for his prank YouTube videos posted under the username "Sam", which have in the past involved such hilarious japes as wearing a prosthetic old man's face and climbing into bed with his own girlfriend. He now lives in LA, but is friends with other prominent British YouTubers, including, of course, Zoella. 

So on the face of it, it's a little surprising that @TheAnonMessage blasted out this tirade against the star last night as a series of tweets to his 170,000-odd followers:

We've been notified of a sick, disturbing video uploaded by @sampepper. Yet again, he uses violent abuse to garner subscribers.

This is something that we cannot stand for. This so-called prank should bring shame to the YouTube community for supporting this imbecile.

This video must be taken down. @SamPepper you have been warned. You have 24 hours or we will unleash fucking hell on you.

The video in question, "KILLING BEST FRIEND PRANK | Ft. Sam & Colby", was published on 29 November but already has over two million views. In it, Pepper teams up with another Sam, half of the YouTube duo Sam & Colby, to pretend to, er, kill him, and terrify Colby in the process.

Sam and Colby drive into shot, then both get out of the car to check the oil. A figure wearing a black balaclava grabs Colby, put a bag over his head, tapes up his hands and dumps him in the boot of the car, all with Sam's help. The pair take him to a rooftop, where the bag is removed, and Pepper - the masked attacker - shoots Colby in the head with a fake gun. The visual references to Isis are hard to ignore:  

Photo: Sam Pepper via YouTube

What follows is a genuinely disturbing thirty seconds in which Colby screams and cries, eventually drowned out and replaced in the video's edit by tinkly piano music. Finally, Sam stands up and reveals he isn't dead. 

YouTubers responded angrily to the prank. Commenters called it "cruel" and seemed genuinely distressed by Colby's experience. The video's approval ratings, represented by thumbs up and thumbs down, are a good indication of audience reaction: 

So what happens if Pepper doesn't remove the video within 24 hours? Gabriella Coleman, author of Hacker, Hoaxer, Whistleblower, Spy: The Many Faces of Anonymous told me that "[@TheAnonMessage] has earned the wrath of Anonymous for acting irresponsibly" in the past (most notably, the user launched an attack on the wrong Ferguson police officer), and isn't part of the main Anonymous group. However, this doesn't mean the user couldn't attack Sam's channel or website. Either way, @TheAnonMessage has leapt on the coattails of a controversy that seems to have caught the imagination of large swathes of social media.

From Pepper's own point of view, though, it's easy to see why the whole furore is a little mystifying. His entire empire is founded on pushing boundaries of acceptability, and no one involved in this particular prank is angry - the video includes an epilogue where he chats to Sam and Colby, and Sam grins and exclaims "that was crazy!".

There's a parallel with the comedian Daniel O'Reilly (also known by his persona Dapper Laughs) here: both are young male entertainers who built an online audience through pushing the envelope with humour and pranks, and are then a bit shocked when they cross an invisible line and are lambasted for behaviour not dissimilar to the actions that earned them followers in the first place. 

Pepper, like Dapper, has been accused of misogyny, and even sexual harassment in his videos - he removed one, "Fake Hand Pinch Prank", which involved grabbing women in public using a fake hand, following online outcry. Yet one of his most watched videos is "How to Make Out with Strangers”, in which he approaches random women in Miami, says things like “I’m seeing which beautiful girls would like to make out…with me,” and kisses them. The video received none of the same criticism, and earned him over 17 million views. You can see why he might not be getting the message. 

The difference between the two videos lies, of course, in consent, as Pepper at least pretends to ask the women's permission in the Miami video. Yet as YouTuber Laci Green gently points out in an open letter to Pepper written at the time: "You pressure women on camera to make out with you - again, many of whom are visibly uncool with it. Confused and caught off guard, they painfully follow through with your requests, clearly uncomfortable."

What's clear is that the internet is still trying to figure out what is acceptable in the realm of humour. Internet-friendly humour tends to be slapstick, brash, irrelevant, and involve making fun of gormless members of the public. But pushed to extremes - the extremes which can seem necessary to make a name for yourself in the saturated vlogger market - these gags can easily turn nasty. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.