In his youth, Michael Ohnersorgen recalls spending his summers on his uncle’s ranch in Arizona. “I remember seeing a lot of pottery and arrowheads and things like that on the ground, and as a kid I always thought that was interesting,” he says. While studying pre-medicine in college, Ohnersorgen discovered that anthropology was the field he really loved. “About mid-way through my junior year, I came to the conclusion that I wasn’t really interested in medicine. I looked at my transcript and saw I had all these anthropology classes, and I realized that is what I really liked.”
Now an assistant professor in the Department of Anthropology at the University of Missouri-St. Louis, where he teaches courses in archaeology, it took Ohnersorgen a couple of years to find his niche. After receiving his Ph.D., he worked for several years as an archaeologist with the Arizona State Historic Preservation Office and the Arizona Department of Transportation, hoping he would someday land a position as a professor. By chance, he went to see a friend’s dissertation defense at Arizona State University, his own alma mater, where a person familiar with Ohnersorgen’s dissertation on the Aztec empire invited him to take a post-doctoral position on a fieldwork project in Mexico. The following year, he applied for and received a National Science Foundation Grant to continue this research.
Currently, Ohnersorgen has been doing fieldwork at the Chacalilla archaeological site on the coast of Nayarit, Mexico, studying a phenomenon known as the Aztatlán tradition. This phenomenon represents a Mesoamerican cultural movement that occurred between roughly 850/900 A.D. and 1300/1400 A.D., when “we see the spread of an art style and cultural tradition that includes really distinctive, complex iconography,” he explains. This particular part of Mexico has not been heavily studied in comparison to other parts of Mesoamerica; Ohnersorgen notes that scholars have been aware of the involved traditions since the 1920s, but that research has been sporadic at best. For such reasons he is vitally interested in how the Aztatlán tradition spread to different cultural groups and what mechanisms were involved during those interactions.
The University of Missouri Research Board grant was absolutely critical for Ohnersorgen to continue his research. As it turns out, he was midway through this long-term project when he came to UMSL, and he did not have access to the necessary equipment and resources with which he had started his work. The UMRB grant allowed him to purchase Global Positioning System equipment and a vehicle to use for the project.
The Aztatlán tradition represents a puzzle for Ohnersorgen, who seeks to understand and arrange its various pieces. For example, remnants of ancient buildings and pottery are scattered throughout the site. Ohnersorgen and his team of investigators have scanned every inch of the area looking for artifacts that might lead to some answers. “We’ve tried to get a sample of artifacts through surface collections and excavation from different kinds of features on the site,” he explains.
Especially interested in the political and economic aspects of the Aztatlán tradition, Ohnersorgen has noted that artifacts associated with the tradition may have been instrumental in building and maintaining a class hierarchy: “We are seeing a distribution of things around the site that shows how elites seem to have had more access to this stuff,” he suggests. Everyone seemed to have some “Aztatlán material,” Ohnersorgen observes, but it was the elite who possessed the “higher-status content.”