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)
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Fark.com’s censorship story is a striking insight into Google’s unchecked power

The founder of the community-driven website claims its advertising revenue was cut off for five weeks.

When Microsoft launched its new search engine Bing in 2009, it wasted no time in trying to get the word out. By striking a deal with the producers of the American teen drama Gossip Girl, it made a range of beautiful characters utter the words “Bing it!” in a way that fell clumsily on the audience’s ears. By the early Noughties, “search it” had already been universally replaced by the words “Google it”, a phrase that had become so ubiquitous that anything else sounded odd.

A screenshot from Gossip Girl, via ildarabbit.wordpress.com

Like Hoover and Tupperware before it, Google’s brand name has now become a generic term.

Yet only recently have concerns about Google’s pervasiveness received mainstream attention. Last month, The Observer ran a story about Google’s auto-fill pulling up the suggested question of “Are Jews evil?” and giving hate speech prominence in the first page of search results. Within a day, Google had altered the autocomplete results.

Though the company’s response may seem promising, it is important to remember that Google isn’t just a search engine (Google’s parent company, Alphabet, has too many subdivisions to mention). Google AdSense is an online advertising service that allows many websites to profit from hosting advertisements on its pages, including the New Statesman itself. Yesterday, Drew Curtis, the founder of the internet news aggregator Fark.com, shared a story about his experiences with the service.

Under the headline “Google farked us over”, Curtis wrote:

“This past October we suffered a huge financial hit because Google mistakenly identified an image that was posted in our comments section over half a decade ago as an underage adult image – which is a felony by the way. Our ads were turned off for almost five weeks – completely and totally their mistake – and they refuse to make it right.”

The image was of a fully-clothed actress who was an adult at the time, yet Curtis claims Google flagged it because of “a small pedo bear logo” – a meme used to mock paedophiles online. More troubling than Google’s decision, however, is the difficulty that Curtis had contacting the company and resolving the issue, a process which he claims took five weeks. He wrote:

“During this five week period where our ads were shut off, every single interaction with Google Policy took between one to five days. One example: Google Policy told us they shut our ads off due to an image. Without telling us where it was. When I immediately responded and asked them where it was, the response took three more days.”

Curtis claims that other sites have had these issues but are too afraid of Google to speak out publicly. A Google spokesperson says: "We constantly review publishers for compliance with our AdSense policies and take action in the event of violations. If publishers want to appeal or learn more about actions taken with respect to their account, they can find information at the help centre here.”

Fark.com has lost revenue because of Google’s decision, according to Curtis, who sent out a plea for new subscribers to help it “get back on track”. It is easy to see how a smaller website could have been ruined in a similar scenario.


The offending image, via Fark

Google’s decision was not sinister, and it is obviously important that it tackles things that violate its policies. The lack of transparency around such decisions, and the difficulty getting in touch with Google, are troubling, however, as much of the media relies on the AdSense service to exist.

Even if Google doesn’t actively abuse this power, it is disturbing that it has the means by which to strangle any online publication, and worrying that smaller organisations can have problems getting in contact with it to solve any issues. In light of the recent news about Google's search results, the picture painted becomes more even troubling.

Update, 13/01/17:

Another Google spokesperson got in touch to provide the following statement: “We have an existing set of publisher policies that govern where Google ads may be placed in order to protect users from harmful, misleading or inappropriate content.  We enforce these policies vigorously, and taking action may include suspending ads on their site. Publishers can appeal these actions.”

Amelia Tait is a technology and digital culture writer at the New Statesman.