Dinosaurs are everywhere……

Fossils can sometimes be found (or are kept) in the most unexpected and surprising places. Recently, a supposedly dinosaurian skull embedded in a block of marble made the news, because said block had been built into an Italian church. While such finds of large vertebrate remains embedded in buildings are rare, ammonites and other invertebrates commonly found in limestones are commonly found in buildings. In southern Germany windowsills are often made from a local Jurassic limestones, and many contain cross sections of ammonites, sponges, brachiopods, bivalves, and corals. When I was a kid my own room had a windowsill made from this material, and it certainly stimulated my interest in paleontology. This experience also allowed me to recognize the purported dinosaur skull as the cross section of a partly crushed ammonite, and other researchers come to the same conclusion. Especially fossil-rich and optically pleasing limestones are sometimes intentionally used for the decorative aspects of the embedded fossils, for example in these staircases of Japanese shopping centers.

Decidedly more unusual is a dinosaur footprint embedded in a band stand, as has happened to what was later designated the holotype specimen of Eubrontes (?) glenrosensis Shuler, 1935, at the Somervell County Courthouse in Glen Rose, Texas.

Eubrontes(?) glenrosensis holotype; image via http://www.sciencedaily.com/releases/2009/11/091104101623.htm

This placement exposes the fossil to erosion, but extracting it from its place for safer storage in museum collections is impossible. The best Thomas L. Adams, Christopher Strganac , Michal J. Polcyn, and Louis L. Jacobs from the Huffington Department of Earth Sciences, Southern Methodist University, could do to preserve the current state of the fossil’s shape was to high-resolution laser scan the surface (the story already made sciencedaily.com a year ago). As they point out, 3D digitizing technology provides a high fidelity but (depending on the specific scanner) low cost means of producing facsimiles.

Eubrontes(?) glenrosensis holotype. 6.1 photograph of the original from 1935. 6.2 laser scan based mesh. 6.3 depth map. Figure 6 of Adams et al. 2010

Additionally, laser scanning with a portable scanner allows touch free (and thus non-damaging) digitizing, while more traditional techniques for creating facsimiles such as molding or casting or mechanical digitizing always carry the risk of scratching, abrading or even totally destroying the fossil. Laudably, the authors provide the scan in various data formats in their paper, along with a Quick Time Virtual Reality Object (QTVR), so that readers without access to a CAD (Computer Aided Design) software can view the 3D scan in high resolution and color. PE has a certain tradition with regards to QTVR: there was an article in the very first volume, Issue 2 about its advantages as an illustrative tool for micropaleontology. But that should not come as a surprise, after all PE is fully electronic (as I continue to keep telling you), and has from the very beginning been a journal for publications centered on 2D and 3D digital visualizations (and that’s only the very first four years!).

But a 3D scan allows more than simply preserving the current status of an object. In comparison to old measurements, photographs and drawings it allows an assessment of the damage the fossil has suffered previously, and can serve as a baseline to monitor future erosion.

Furthermore, because of the minimal difference in shape between the original and a scan (for which Adams et al. propose the term ‘digitype’), the latter could replace the actual type specimen of a taxon if it gets lost or destroyed. Physical copies can be created as high accuracy as well, by rapid prototyping or 3D printing techniques. Currently, the ICZN code does not allow this, a dated view considering the high quality of scanning techniques available today. My own experience with, e.g., CT-scan based files of Plateosaurus and laser scan based files of Kentrosaurus (sorry, this one not open access) has convinced me that digital 3D files will become more important for research in the future. Others have been diligently building databases, sometimes making their data freely available, for example the Witmer Lab (read their blog), or Texas University’s Digimorph library.

While these examples concentrate on body fossils, tracks and trackways have been documented by laser scanning before (e.g., thousands of tracks in Spain or the first occurrence of stegosaur tracks in northern Africa [PDF]) or by other digital methods.  Relatively cheap and easily transportable scanners increasingly allow high quality scanning almost anywhere, and while many trackways are less easily accessible in the field than the Eubrontes (?) glenrosensis holotype, researchers should always consider laser scanning as a mode of documentation. Never was obtaining high quality 3D data this easy, either scanning specimens or receiving data from other researchers – and things will only get better in the future – Adams, Strganac, Polcyn, and Jacobs drive this home with a beautiful example.

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