7 MILLION-YEAR-OLD ELEPHANT HERD REVEALED IN PRINTS
The most extensive set of fossilized mammal footprints ever found has allowed scientists to recreate how elephants lived 7 million years ago.
Co-author Brian Kraatz told Discovery News that the trackway “shows the oldest evidence of complex social behavior within elephants.”
“It’s an amazing locality,” added Kraatz, who is an assistant professor in the Department of Anatomy at the Western University of Health Sciences.
“Basically, this is fossilized behavior,” Faysal Bibi, lead author and a researcher at the Institut International de Paléoprimatologie and the Museum für Naturkunde, was quoted as saying in a press release. “This is an absolutely unique site, a really rare opportunity in the fossil record that lets you see animal behavior in a way you couldn’t otherwise do with bones or teeth.”
Bibi, Kraatz and their colleagues can tell that the prehistoric elephant herd consisted of at least 13 individuals. They walked through mud and left tracks that hardened, were buried and then re-exposed by erosion. Analysis of trackway stride lengths reveals the herd contained a diversity of sizes, from adults to a young calf.
An 853-foot-long trackway of a solitary male at the same site indicates the elephants differentiated into solitary and social groups, and that these might have been sex-segregated just like in elephants today.
Among living elephants, adult females lead the herds while males disperse at sexual maturity and come back only to mate. This same type of behavior is also suggested at the Mleisa 1 site.
“The Mleisa 1 fossil trackways are the most extensive ever recorded for mammals,” said William Sanders, a paleontologist at the University of Michigan who was not involved in the study. “Bibi et al.’s analysis is an exemplary and comprehensive example of what can be garnered from ancient footprints.”
Mleisa 1 is one of the largest trackway sites in the world, covering an area of 12.5 acres. Though the site had been known for some time, it was only when the scientists photographed it from the air that its significance became clear.
“Once we saw it aerially, it became a much different and clearer story,” Kraatz said. “Seeing the whole site in one shot meant we could finally understand what was happening.”
“The trackways are visually stunning.” co-author Andrew Hill said. “It is quite obvious to anyone, without any technical knowledge, that these are the footprints of very large animals, and to learn that they are over 6 million years old presents a visitor with the sensation of walking back in time, across a Miocene landscape where elephants might have strolled by just a little time before.”
Photos, from top: 1. A reconstruction of an elephant herd that lived 7 million years ago. Credit: Mauricio Antón. 2. A simulated oblique view of the 7-million year old Mleisa 1 trackways with digitized Stegotetrabelodon elephants inserted. Credit: Mauricio Anton. 3. The ancient elephant tracks go off into the distance. Credit: Faysal Bibi.