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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The art of the YouTube Poop

What are YouTube Poops and why do we need them now, more than ever?

“The world today doesn't make sense, so why should I paint pictures that do?”

So, allegedly, said Pablo Picasso in a shrewd attempt to justify his love of putting noses where noses don’t actually go. It is imperative that you now hold this profound quotation firmly in your mind whilst you watch this four minutes and 57 second long clip of Arthur – the cartoon aardvark – being tormented by squirrels.

What you have just seen is an example of the art form primarily known as “YouTube Poop” (YTP). Beginning in the early Noughties, this cultural movement is characterised by confusing and shocking edits of Saturday-morning cartoons, video games, and viral videos. Though the Tens have seen the genre decline in popularity, the YTP is, nonetheless, one of the defining innovations of our era.

Those in the Poop community don’t actually like being labelled as artists, as one Yale student found out when he attempted to define them as such on the University’s technology blog. Though they have been compared to Dadaism, YTPs are more vile, violent, and most importantly, nonsensical than most artworks, but this is precisely why they are an asset to our age. In a world where – sorry Pablo, you got nothing on us – absolutely zero things makes sense, it is time for the YTP to have a comeback.

Despite its seeming randomness, the world of YTP is not without its rules. “Poopisms” are the common techniques and tricks used in videos to ensure they qualify as a true Poop. They include “stutter loops” (the repetition of clips over and over), “staredowns” (freezing the frame on a particular facial expression), and the questionably-named “ear rape” (suddenly increasing the volume to shock the viewer). One of the most humorous techniques is “sentence mixing”: forcing characters to say new sentences by cutting and splicing things they have said.

There are also firm rules about what not to do. Panning across a clip without adding another Poopism at the same time is considered boring, whilst using your own voice to dub clips is seen as amateur. By far the biggest barrier that Poopers* face in creating their videos, however, is the law.

Despite what many eight-year-olds on YouTube think, declaring that something is a “parody” in the description of a video does not make it exempt from copyright laws. The video below – regarded by at least two commenters as “the best YouTube Poop” ever – is missing audio 20 minutes in, as the creator was hit by a copyright claim.

Yet even the iron fist of the law cannot truly stop Poopers, who are still going (relatively) strong after the first YTP was created in 2004. YouTube Poops now even have their own Wikipedia page, as well as a page on TV Tropes and a WikiHow guide on how to create them, and for good measure, avoid them.

YouTube Poops have therefore undoubtedly secured their place in history, and whilst you might wander into a comment section to declare “What have I just watched?”, remember that Pablo Picasso once said: “The purpose of art is washing the dust of daily life off our souls.” He almost definitely wasn’t talking about “You are a Sad Strange Little Man” by cartoonlover98, but still.

* The term “Poopists” was rejected by the community for being “too arty”.

 

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