3D printing of dinosaur fossils

[Dr. Mike]

In April I reported about the use of CT scanning and 3D printing to create replicas of dinosaur fossils while still leaving the original fossils in their rocky matrix. I am wondering if any Embodi3D members have any personal experience with doing this type of work. How are you doing the scans? Any specific software that you are using to create your 3D models?

 

Thanks

 

Dr. Mike

[Michael Holland]

Hi, Dr. Mike -

This is happening in some instances.  CT scanning is sometimes able to yield good images of fossils within rock matrix, but results can vary considerably depending on the matrix.  If the bone and the rock matrix are very similar in density, the scanner has trouble distinguishing one from the other.  When successful, having a 3D glimpse into the rock can be very helpful in preparing the fossil.  Better still, if the preparator can have a 3D print of the fossil (with matrix removed) sitting on the work bench next to the fossil, they can know what lies beneath the rock as they remove it.  This can help them to decide which areas to work on first, and advise them of potentially thin or fragile regions of the fossil. 

A few years ago I had a specimen scanned at our local hospital.  In that case, I had a fossil that had been prepared almost completely, but with sandstone matrix remaining in some regions.  Within the sandstone I could see the broken edges of what appeared to be thin slices of bone, and I wanted to know how far those bone pieces went into the fossil in order to determine if they were part of that same bone or if they were separate elements.  My suspicion was that they were separate elements, but before attempting to separate them, I wanted verification. 

The CT scans showed that my suspicion was correct, and that these "floating" slices of bone were in fact part of different bones (anterior pterygoids).  This helped me to determine how to finish preparing the fossil, but even more importantly it also offered in-situ proof of the correct orientation of these bones in this animal.  The animal in question was Tyrannosaurus rex, and this new information offered an arrangement of the palatal anatomy of this species that is different from the previous arrangement that had been figuring into the scientific literature since the genus was first described a century ago.  A closer look at previously recorded CT scan data from another well-known T. rex specimen showed the same orientation of the bones in question, offering further confirmation. 

I'll ask around to see who else might be using CT scanning and 3D printing to get a "preview" into a fossil specimen, and what software is being utilized.  Stay tuned...

   MH

[Dr. Mike]

Thanks for the great post Michael,

 

I guess medicine and paleontology aren't that different. Neither a surgeon nor a paleontologist wants to cut through something without knowing if a vital structure lies underneath. 

 

Please let us know what you find out about current efforts to use 3D printing in paleontology. We would love to hear more about it.

 

Dr. Mike

[Michael Holland]

I've been getting some responses to my question for peers who work in paleontology, and they've offered some interesting thoughts on using 3D scanning and printing in fossil preparation.  Below is the response from my friend Matt Brown:

I remember seeing my very first 3D printed CT scan at the Dinosaur/Bird Evolution Symposium in Florida in 2000. My preparator's response to the enthusiastic exhibitor was that he was going to put me out of a job. Almost fifteen years later, I'm confident that this isn't the case, and that CT and 3D printing are very valuable additions to the preparator's toolkit. Groenke et al. presented on the use of medical CT at the 2007 SVP meeting, Balcarcel discussed some considerations in 2011, and in 2012, Marsh et al. and Colbert and Brown presented on some case studies. There are at least a few other examples that I can't think of off the top of my head (I think Cornish et al. 2010 in the Geological Curator? Discusses Archaeopteryx, I believe), and in 2010 Tim Rowe and I gave a talk discussing ways to integrate CT along with other new technologies into the preparation workflow, and a few institutions have since made this part of their common practice.

As a quick aside, I consider any digital segmentation of fossil datasets to amount to fossil preparation, this includes all those kinds of pretty spinning 3D models (see: Digimorph.org) presented at conferences over the years since UTCT hit the scene in the late 90s, and have accelerated with all of the new labs built since then. We've now got several generations of digital preparators out there, some of whom may not even realize that they are!

Back to your question of printing, 3D printouts can indeed be useful in the lab, and in ways that might not seem obvious at first. Scaling up a model of a microfossil can yield amazing insights into anatomy that is normally only visible under magnification, and rarely can you fit an entire specimen into the field of view. A 3D print out can be a tremendous aid from that perspective, additionally, just as scientific illustrators can remove obscuring anatomy with pen or pencil, the digital preparator can use the power of Xrays to reveal data under rock or other bones. Joe Groenke has recently done some amazing work making hybrid casts with both traditional molding/casting and digital printouts.

For me, the real power of CT integration in the prep lab lies not in printing however, but rather the raw data itself. A stack of DICOM or JPG files open on a computer are a game-changing addition to the preparation toolbox. Mounting a monitor near my workstation, I would use a wireless mouse to scroll through stacks of CT slices to help guide my way through a block of matrix. Members of the research team can develop a strategy early on to determine where work needs to be done, as well as the safest approach to reveal new data while minimizing risk to delicate specimens. Projects can be prioritized in this way, and even though the scans will probably cost money, the potential time, money, and risk saved by scanning specimens first must be factored in to total cost. Digital preparation is just another skill, like mechanical or chemical preparation, for the 21st century preparator to master.


Matthew A. Brown
Head of Collections, Vertebrate Paleontology Laboratory
Lecturer, Department of Geological Sciences
Jackson School of Geosciences
The University of Texas at Austin

[Michael Holland]

Anthony Maltese of the Rocky Mountain Dinosaur Resource Center in Wyoming has this to say:

We took a stab at it recently with the articulated Hell Creek gar that I
found back in 2010. There was no chance of me taking it apart and the
researcher I was working with was really interested in seeing the lower jaw
lodged under the head. The result here https://skfb.ly/BS6Z let us get a
look at both it but also the neurocranium, ribs, verts, etc.

I'm considering printing one out for my desk.

 

Anthony Maltese
Curator
Rocky Mountain Dinosaur Resource Center

[Dr. Mike]

Dear Michael,

 

Thanks for the amazing insights about 3D printing in paleontology you have shared with this forum. In many cases the rationale for using 3D printing in fossil preparation is identical to that of using 3D printing for presurgical evaluation in medicine - you are dealing with something very delicate where the stakes are high and there is only one shot at it. 

 

Matthew Brown's comment about setting up a CT workstation to view slices during fossil preparation makes sense. Similar setups have been in operating rooms for years, allowing surgeons to refer to patient CT scans during surgery. There are limitations however when viewing 2D images. For example, if you are looking at a CT image in the X-Y plane then structures that are in the Z plane can be difficult to conceptualize. As a radiologist I have looked at tens of thousands of CT scans, and with practice you can get the hang of it. But, I am still frequently surprised at how differently things look on a 3D reconstruction than I expect them to based on the 2D images. With 3D printing you can take things a step further and hold the model in your hand, which provides an additional way to assess the structure (tactile), as opposed to just visual. The human brain didn't evolve to process stacks of 2D images, and 3D models are just easier to understand -- even for people who make a living reading 2D image stacks!

 

I recently attended the 2014 RSNA meeting during which radiologists from Mayo Clinic presented their work in which they made 160 3D printed models as part of pre-surgical planning. Their surgeons already had access to high quality CT scans and 3D digital reconstructions of all of their patients. But once they had the ability to actually hold the models in their hand as part of their surgical planning they never wanted to go back. The lab is now experiencing exponential growth in requests for 3D printed models. I expect that 3D printing will similarly provide advantages in paleontology, not only in fossil preparation but also in research and education.