Footprints seem so inconsequential, unless they are 19,000 years old and discovered en masse. In 2006, a local villager, Kongo Sakkae in Engare Sero , Tanzania found ancient footprints. While in the area in 2008, conservationist Jim Brett learned of the site and photographed it. He shared them with a colleague, Dr. Cynthia Liutkus-Pierce and a long-term research project began. Dr. Liutkus-Pierce and her research team just published their findings after careful study.
Over 400 well-preserved footprints are preserved in a series of “fluvially reworked debris flows” from the nearby Oldoinyo L’engai volcano, a peak 7,650 foot tall towering over Lake Natron. The volcano is a sacred pilgrimage site for the Maasai tribe to honor their god Engai.
The prints tell a tale of life during ancient times. There is group of twelve women and children who appear to be traveling together. One set of prints reveals the person walking with a broken toe. Other prints reveal person appearing to be jogging.
William Harcourt-Smith, a paleoanthropologist at the City University of New York and member of the research team says,
There’s one area where there are so many prints, we’ve nicknamed it the “dance hall,” because I’ve never seen so many prints in one place … it’s completely nuts.
Initially, the researchers thought that the mud preserving the footprints had resulted from falling ash followed by a volcanic eruption. This led them to estimate the age of the prints to be about 120,000 years old.
Further research revealed different dating. The ash actually had been carried by water and a crystal present in the mud determined the age to be younger. The shell in the mud above the footprint led the team to conclude that the footprints were really between 5,000 and 19,000 years old, placing them in the late Pleistocene epoch.
Dr. Cynthia Liutkus-Pierce a geologist from Appalachian State University and National Geographic grantee, who led the study, explains,
Immediately after the footprints were pressed into the wet mud and ash, the wet sediments dried out and hardened.. We see evidence of this because footprinted surface has large polygonal mudcracks in it. However, our laboratory research indicates that once that hardened mud and ash gets wet again, traces of any impressions are destroyed. Therefore, in order to preserve the Engare Sero footprints, the hardened, dried surface had to be buried soon after it formed.
Preserving the archaeological site containing the footprints has been another challenge. The site is fenced off from onlookers. To be safe, researchers with help from the Smithsonian have created 3-D scans of the entire area.
The footprints at Engare Sero add to the unique record of fossil footprint sites throughout the world. They record traces of our ancestors, their activity and behavior during the latest Pleistocene along the margin of Lake Natron in Tanzania.