Recent Discoveries at Teotihuacan: Excavations at the
Plaza of the Columns
Free admission and stream online
As part of a circuit of conferences
called “Archaeology Today” (coordinated
by Dr. Leonardo López Luján), Dr. Saburo Sugiyama and Dr. Nawa Sugiyama, co-directors
of the Project Plaza of the Columns Complex, will present an interesting
lecture on the most recent discoveries at Teotihuacan made by their project.
Multiple aspects of Teotihuacan,
such as urban planning, new LiDAR maps of the Teotihuacan Valley, the arrival
of Maya elites, and the sacrifice of animals, will be revealed to the general public.
Do not miss this opportunity to attend the Colegio Nacional next Wednesday, June 12th, at 6pm. If you can’t make it in person, check out www.colnal.mx to stream online.
The Elements of a Paleodiet: How Isotope Analysis Help Archaeologists in the Lab
Food is an important
part of our lives, yet it is a difficult thing to see in the archaeological
record. Usually archaeologists rummage through ancient trash piles to look for
animal bones and residues in pots to find out what people ate. However, there
is another tool that archaeologists use that can tell us more about what people
and animals consumed called stable isotope analysis. This methodology helps
archaeologists understand the chemical make-up of human and animal bones to
reveal information regarding diet, social organization, and human-animal
interactions. At the Archaeological Sciences Lab
at George Mason University, I help prepare bones in order to extract that
All living organisms
are comprised of molecules that they have absorbed or eaten throughout their
lives. Bones, teeth, and even hair molecules can tell archaeologists a lot
about an organism’s life history and environment. These molecules, referred to
as stable isotopes, and their composition can vary depending on the environment
of the organism. Factors such as temperature, altitude, nutrition, and humidity
affect isotopic composition and will be reflected in the tissues we look at.
There are several isotopes that can be analyzed such as carbon, oxygen,
nitrogen, and strontium.
Carbon is most familiar
as the lead in our pencils and what we breathe out in carbon dioxide, but
carbon also relates to the way plants obtain energy or photosynthesis. C3 and
C4 cycles are the most common photosynthetic pathways a plant can use and can be
determined from bones of an animal or person who ate plants. Since
photosynthesis varies among plants, archaeologists can reconstruct what people
and animals were eating, where they lived (based off where the plants grew),
and how their diet changed over time. This is the information that can be
deduced from carbon alone. It is important to collect the information stable
isotope analysis provides. So, how do archaeologists conduct isotope analyses?
In the Archaeological
Sciences Lab I help prepare the bones to extract the isotopic information we
need. The bones from the Project Plaza of the Columns Complex (PPCC) are
cleaned after excavation. Then, the bones are analyzed, identified to species,
photographed, and documented for further reference. It is important to document
the bones well because isotope analysis is a destructive process. First, I make
sure the bones are cleaned completely. Using a hand rotary tool, I thoroughly clean
off any excess dirt and build-up on and inside the bone. I also use the rotary
tool to remove a part of the bone that will be used for the isotopic analysis.
Then, I wash the bones in a sonic bath which uses high frequency sound waves to
remove any remaining dirt that cannot be removed by hand.
After letting the bones
dry overnight, I use an agate mortar and pestle to crush the bones into a fine
powder. I weigh each sample and transfer them to tubes so they may soak
overnight in a chemical solution to begin the removal of organic components.
Then, the samples are rinsed in ultrapure water, and an acid solution is used
to completely remove all organics in the sample. Once weighed a final time, the
sample is ready for the mass spectrometer at the Smithsonian
Museum Conservation Institute. The mass
spectrometer is able to measure isotopic variations in a sample. It is through
those variations that archaeologists can gain insight on the diet of the
individual and the ecosystem they lived in.
At first glance,
isotope analysis is intimidating to someone with little experience with heavy
machinery and chemicals. However, since working at the Archaeological Sciences
Lab, I have greatly enjoyed my time learning about isotopes and the many
questions about ancient life that can be answered through this process. Stable
isotopes open a new window into ancient life that tell archaeologists about
more than just food consumption. At the PPCC, isotope analysis has helped
investigators find out more about animal
management and how it had affected social
structure in ancient Teotihuacan. The potential use of isotope analysis is
quite vast, and archaeologists still have much more to discover using this
France, Christine A.M., Douglas W. Owsley, and Lee-Ann C. Hayek. “Stable Isotope Indicators of Provenance and Demographics in 18th and 19th Century North Americans.” Journal of Archaeological Science 42 (2014).
Schwarcz, H.P, M.J. Schoeninger. “Stable Isotopes of Carbon and Nitrogen as Tracers for Paleo-diet Reconstruction.” In Handbook of Environmental Isotope Geochemistry, by M. Bakaran, 725-742.
Sugiyama, Nawa, A.D. Somerville, M.J. Schoeninger. “Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica.” Plos One 10, no. 9 (2015).
Sugiyama, Nawa, William L. Fash, and Christine A.M. France. “Jaguar and Puma Captivity and Trade among the Maya: Stable Isotope Data from Copan, Honduras.” Plos One 13, no. 9 (2018).
White, Christine D. “Stable Isotope and the Human-Animal Interface in Maya Biosocial and Environmental Systems.” Archaeofauna 13 (2004). 183-198.
Due to popular demand, the Phoenix Art Museum added an additional lecture by archaeologist Nawa Sugiyama (Assistant Professor, Department of Sociology and Anthropology, George Mason University, and co-director of the Project Plaza of the Columns Complex) who will present a 40-minute lecture on the sacred animals, sacred places, and ritualized landscapes at Teotihuacan.