By Elizabeth Lunday
On the edge of the Louisiana State University campus sits two eighteen-foot tall, conical earthen mounds constructed by ancient Native Americans. Known as the LSU Campus Mounds, they are a local landmark and for many years they were a popular location for picnics and barbecues during football games.
These mounds, named A and B, may have significance that reaches far beyond the LSU campus. A paper published this summer in the American Journal of Science proposes that the mounds are older than previously believed—much, much older. Their construction began around 11,000 years ago, according to the paper’s lead author, Brooks Ellwood, an LSU geophysicist who has worked on numerous archaeological projects, and seven coauthors. This would make the LSU mounds roughly 4,000 years older than any other mounds in the lower Mississippi River Valley, and the oldest-known human-made structures in the Americas.
But questions have been raised about the paper’s conclusions. Some scientists familiar with the LSU mounds believe Ellwood and his colleagues misinterpreted data about them. Six archaeologists who have researched the mounds coauthored a rebuttal that was published in the November issue of the SAA Archaeological Record, a publication of the Society of American Archaeology. The debate is far from settled. If Ellwood and his colleagues are right, the textbooks about mound building will need to be rewritten. And even if the dates are not confirmed, the dispute serves as a case study of how science advances.