Two ancient humans with slightly different gaits crossed paths in East Africa.
Footprints preserved on the once muddy lakeshore reveal that two species, each adapted to walk in its own way, lived there about 1.5 million years ago.
Newly discovered footprints in northern Kenya and previously unearthed footprints in nearby areas provide a glimpse into coexistence and direct contact between ancient human species spanning up to 200,000 years, says paleoanthropologist Kevin Hatala of the University of Pittsburgh-Chatham. ) says: colleague.
Scientists reported on November 29 that two patterns of upright walking appear in footprints found along an ancient lake in Koobi Fora, a sedimentary layer on the eastern edge of what is now Lake Turkana. science. A similar distinction applies to footprints discovered at Ileret, another Kenyan site dating back about 1.5 million years, during a field study led by Hatala about 20 years ago, the team said. (SN: February 26, 2009).
Fingerprints showing human-like foot anatomy and gait homo erectusPossibly a direct ancestor of H. sapiensHatala says. H. erectuslived from about 2 million to about 117,000 years ago and ate a variety of energy-rich foods to support their large brains.SN: 19/12/18).
Here are some impressions that bear little resemblance to the foot and stride patterns of people today: Paranthropus boiseiInvestigators are suspicious. small brain, big jaw P. Boiseiwhich is believed to be 2.3 to 1.2 million years old, loved flowering plants called grasses and sedges.SN: May 2, 2011).
Researchers have been studying fossils from East Africa for nearly 50 years. H. erectus and P. Boisei Have a date at a nearby location around the same time. But because the fossils accumulated slowly, researchers were unable to determine whether the two species lived in the same place at the same time.
The preserved footprints analyzed in the new study address this question, said Jeremy DeSilva, a paleoanthropologist at Dartmouth College who was not part of Hatala’s team. “Now we have these two types of [hominids] “We shared the same scenery and walked with slightly different gaits.”
Closely spaced footprints at the new Koobi Fora site, which consists of three H. erectus Impressions and the traces left by 12 impressions P. Boisei The object was formed and buried in lakeshore sediments within up to a few days, researchers say. The same was true for the tracks of large birds and animals such as antelopes and wild horses.
“Eden homo and Paranthropus “If individuals were passing through this area hours to a day apart, or seconds to minutes apart, they would have been aware of each other’s presence in this shared landscape,” says Hatala.
If chimpanzees and gorillas could feed peacefully from the same tree, H. erectus and P. Boisei Bernard Wood, a paleoanthropologist at George Washington University in Washington, D.C., said he was not involved in the new study. .
According to the results of the footprint survey: H. erectus and P. Boisei “It is not possible to determine from current evidence whether or when they potentially competed due to climate or environmental pressures,” said Rita Sorrentino, a paleoanthropologist at the University of Bologna in Italy.
Whatever happened along the ancient lakeshore, the Kenyan footprints support previous reports of variation in upright posture among older human species. 3.6 million-year-old footprints at the Laetoli site in Tanzania contain human-like impressions of Lucy’s species. Australopithecus afarensis and chimpanzee-like footprints of an unidentified human species (SN: 11/13/24 ; SN: 12/1/21).
In the new study, researchers compared digital 3D models of ancient human footprints and footprints with those made by modern-day people traversing clay soils along ancient lakes, including Kenyan shepherds who wore little or no shoes. Mud footprints made by chimpanzees provided further comparison.
The arches formed by human footprints when walking in the mud are very similar to those left behind by humans. H. erectus In the ancient lake, Hatala speaks. The findings indicate that: H. erectus He claims he moved his feet as much as we do now.
P. Boisei The footprints showed flatter arches than those of modern humans, showing that their foot movements and possibly foot anatomy were different from ours, Hatala says.
P. Boisei — but it isn’t H. erectus — They also had more spread big toes than people do today, but less than what is observed in chimpanzees. P. BoiseiOne’s big toe may have been more mobile than another person’s big toe. H. erectus Or modern humans, Hatala suggests.
This foot imbalance is the basis for two relatively effective forms of walking. “The trackway we think of is P. Boisei Reflecting a fairly fast walking speed, there is no evidence that they lost balance or were less adept at walking on two legs. H. erectus” says Hatala.
