Computer-Tomography-Laboratory

Mikro-Computer-Tomograph im Labor der Paläontologie
Micro-CT in the lab facilities at the paleontological institute

The Micro-Computer Tomography Laboratory at the Chair of Paleoenvironment

Geoscientific questions often require an examination of both the interior of rocks and the fossils they contain. Until now, traditional preparation methods have mainly involved the destruction of the sample material (sectioning, thin sectioning, and serial sectioning).

The emergence of computer tomography technology in the 1970s revolutionized medicine. Intensive research in this field since the 1980s has also led to the development of industrial computer tomography. Since the early years of the new millennium, this technology has become particularly interesting for sedimentological and paleontological/biological research, both in terms of its affordability and its performance. It is now possible to analyze and document the internal structures of rocks without destroying them.

Innenraum des Computer-Tomographen
Interior of the computer tomograph with the two X-ray tubes (right), the sample manipulator in the middle, and the detector (left)

Do you need scans of your samples for your research? Contact us: christian.schulbert@ fau.de oder telefonisch +49 9131 8524851.

Here are some examples from our laboratory that illustrate the possibilities offered by non-destructive material testing technology:

Morphological analyses of the shells of marine unicellular organisms in the submillimeter range. The raw 3D volumes are displayed in grayscale depending on the material density. Software can be used to segment this grayscale data into colors, which allows structures such as surfaces to be displayed more clearly. In the case of the recent foraminifer Calcarina, the calcareous shell and the cavity (blue) enclosed by the shell (yellow) are shown here.
Segmented volumes can also be shown and hidden, as well as virtually cut, to provide insights into the internal structures.

Rendering des Gehäusehohlraums der Foraminifere Calcarina
Rendering of the shell cavity of the foraminifer Calcarina
Schnitt durch das Gehäuse der Foraminifere Calcarina
Cross-section through Calcarina
Rezente Foraminifere Calcarina
Recente foraminifer of the genus Calcarina
Schnitt durch einen bioerodierten Kalkstein
Bioerosion in a carbonatic rock

Bioerosion of organisms on other organisms or on inanimate substrates is widespread in both recent and fossil contexts. With the help of 3D volume data from CT scans, traces of bioerosion can be visualized and analyzed in a non-destructive manner. In this way, it was possible to identify the various groups that had hollowed out a limestone rock from the Mediterranean Sea. In the 2D section, for example, the shells of a boring mussel can still be seen in some cavities, which, along with many specimens of a boring sponge, caused the perforated structure of the once compact limestone.

Darstellung des durch Bioerosion enstandenen Hohlraums in einem Kalkstein-Handstück
Depiction of the cavity created by bioerosion in a limestone handpiece

While a two-dimensional cross-section of an object already provides a wealth of information, this can be greatly expanded upon by using 3D representations of structures. Here, the cavities in the limestone have been vividly depicted, while the limestone itself has been removed or hidden. This structure was created by the marine boring sponge Cliona, which connects its many chambers with fine channels.

Backenzahn "Weisheitszahn" eines Menschen aus Hunas
Molar “wisdom tooth” of a human from the cave ruins near Hunas. At more than 250,000 years old, this tooth is the oldest evidence of human existence in Bavaria.

Our collection includes the wisdom tooth of the oldest human fossil found in Bavaria. Examinations of surrounding stalactites revealed an age of more than 250,000 years. At that time, representatives of our species were probably already living in the region, but Neanderthals were also widespread. Morphological measurements are necessary to determine which human species this tooth belongs to (the investigations are still ongoing).

Schnitt durch die pleistozäne Koralle Porites mit deutlichen Wachstumslinien
Cross-section of the Pleistocene coral Porites with distinct growth lines

Coral skeletons are an excellent archive for climate research into temperature developments during the Pleistocene. Growth rates can be calculated, for example, using growth lines on the coral skeleton. In a seasonal rhythm, corals alternately build dense and less dense stripes into their skeletons. These differences in density can be easily detected and measured using computer tomography methods.

Oberkiefer-Gebiss des jurassischen Raubfisches Piranhamesodon
OberUpper jaw of the Jurassic predatory fish Piranhamesodon

For vertebrate paleontologists, the internal structures of their objects of study are often inaccessible. However, in most cases, it is not possible to make thin sections and cuts through vertebrate fossils. In the case of the fish fossil Piranhamesodon from the limestone slabs of Ettling in the Altmühltal valley, it was only possible to determine that there were additional rows of teeth in its mouth on the palate using computer tomography methods. https://doi.org/10.1016/j.cub.2018.09.013

Darstellung des Porenraums in einem Sandstein
Representation of the pore space in sandstone

Sedimentologists can use CT data to visualize and measure the pore space in rocks. Pores and pore connections provide insights into the transport of liquids (or gases), such as groundwater or petroleum.

 

 

Micro computer tomograph

Gerät zur zerstörungsfreien Untersuchung von Proben aus unterschiedlichsten Disziplinen:

  • Paläontologie
  • Geologie
  • Biologie
  • Archäologie
  • Medizin
  • Mineralogie
  • Materialwissenschaften
  • Metallurgie
  • Ingenieurswissenschaften

Probengröße bis maximal 25 x 35 cm bei bis zu 10 kg Masse. 
Die erreichbare Auflösung hängt u.a. von der Probengröße ab und geht bis etwa 0,8 µm.
Manufacturer: General Electric
Model: Phoenix v|tome|x s 240
Construction Year: 2016
Location: Erlangen
URL: https://www.gzn.nat.fau.de/palaeontologie/ausstattung/computer-tomographie-labor/
Funding source: Deutsche Forschungsgemeinschaft (DFG)

Related Research Projects:

Related Publications: