Hello and welcome once again to Virtebra, the Virtual Bones and Artifacts Lab at the University of West Florida! My name is Mariana Zechini, and I am a graduate research assistant in the Anthropology department. I am responsible for creating and printing 3D models of artifacts for Virtebra.
In 2013, Dr. Kristina Killgrove received the first molars of 22 individuals from the Petriplatz site in Berlin, Germany, thanks to archaeologist Claudia Melisch. Claudia directed the excavations from 2007 to 2010. The goal of the excavation was to uncover the town center of Cölln, the medieval sister city of Berlin. Cölln and Berlin were founded on the opposite sides of the Spree River, most likely during the 13th century. During the excavations, Claudia and her team uncovered the church of St. Peter (St. Petri-kirche), its cemetery, the town center, and the surrounding habitation area. The cemetery contained 3,124 graves with 3,718 bodies, making it one of the largest, if not the largest, medieval cemeteries in Europe. Most of the teeth that Dr. Killgrove received came from individuals from the cemetery’s earliest occupation (1200-1300) and two individuals date to the later occupations of the cemetery (1400-1600).
Dr. Killgrove took the teeth to the Isotope Geochemistry Lab at UNC Chapel Hill and, under the direction of Dr. Drew Coleman, performed strontium isotope analysis on the teeth to understand where the earliest settlers of Berlin came from. Dr. Killgrove and Dr. Coleman found that 3 of the 20 individuals have strontium isotope values that do not match up with the strontium value for Berlin. These results indicate that those three individuals came from elsewhere in Germany.
Before drilling the teeth to take samples for strontium analysis, Dr. Killgrove 3D scanned them using the NextEngine 3D scanner. For the past few weeks, I have been editing and printing models of the teeth in order to create an interactive and comparative 3D collection. So far, I have successfully printed two teeth from female individuals – one with a strontium isotope value of .713, which is similar to the geology of west-central Germany, and the other with a strontium isotope value of around .711, which is more similar to the geology of Berlin.
During the editing process, I encountered very few problems. Fusing the model turned out to be the most difficult part of the process. Instead of binding multiple models together and filling any holes, fusing would not fill any data gaps but instead add more holes to the object. I found a way to alternatively fuse the models by using the “remesh” option on the software. This option created a smooth, clean and completed digital model.
The digital models of the teeth can be shared with researchers and archaeologists associated with Petriplatz. They allow us to keep exact replicas at UWF for further study once the teeth are sent back to Germany. The digital and printed models could even be used in interactive demonstrations to teach others about archaeological excavations at Petriplatz. In addition, the teeth allow us to ask questions about health and diet of individuals living in Berlin and Cölln during its founding years. Over the next few weeks, I plan to continue editing and printing teeth in order to create a larger digital and printed collection. The teeth that have been scanned and modeled so far can be found at the Virtebra repository on GitHub.
For more on the Berliners project and the excavations at Petriplatz, see:
- Petriplatz – Wo Berlin begann! (Powered by Osteons blog)
- Whence the earliest Berliners? (Part 1) (Powered by Osteons blog)
- Berlin’s Forgotten Half: Excavations Shed Light on History of Cölln (Spiegel Online)
- Ein alter Baum und mehr als 700 Skelette (Berliner Zeitung)
- 2012: 775 Years of Berlin (Berlin.de)
- Archaeologist Claudia Melisch’s Academia.edu page, which has numerous articles on the excavations at Petriplatz