1.5-million-year-old ancient human footprints found in Kenya

During the Pliocene and Pleistocene epochs, several hominin species lived in the same areas of eastern and southern Africa. However, because the skeletal fossil record is incomplete, it is unclear how these species interacted with each other.

A new study by an international team of scientists reports the discovery of footprints (~1.5 million years old) from Koobi Fora, Kenya. This discovery offers the first evidence of two different patterns of Pleistocene hominin bipedalism appearing on the same footprint surface.

It proves that some ancient hominins were neighbors.

Scientists said, “More than a million years ago, on a hot savannah teeming with wildlife near the shore of what would someday become Lake Turkana in Kenya, two completely different species of hominins may have passed each other as they scavenged for food.”

Scientists have uncovered 1.5-million-year-old fossils, revealing the earliest known example of two sets of hominin footprints created around the same time on an ancient lake shore. This discovery offers valuable insights into human evolution, shedding light on how early human species cooperated and competed with each other.

Craig Feibel, the study’s author and a professor in the Department of Earth and Planetary Sciences and Anthropology at the Rutgers School of Arts and Sciences, said, “Their presence on the same surface, made closely together in time, places the two species at the lake margin, using the same habitat.”

Study confirms the age of oldest human footprints found

Feibel, a researcher in northern Kenya since 1981, used his expertise in stratigraphy and dating to confirm that the fossils are 1.5 million years old. He also analyzed the depositional setting of the footprints, determining that the tracks were made within a few hours of each other on soft sediments at the site. This suggests that the hominins crossed paths or walked along the shore quickly.

Kevin Hatala, the study’s first author and an associate professor of biology at Chatham University in Pittsburgh, Pa., said, “While skeletal fossils have long provided the primary evidence for studying human evolution, new data from fossil footprints are revealing fascinating details about the evolution of human anatomy and locomotion and giving further clues about ancient human behaviors and environments.”

“Fossil footprints are exciting because they provide vivid snapshots that bring our fossil relatives to life. With these kinds of data, we can see how living individuals, millions of years ago, were moving around their environments and potentially interacting with each other or even with other animals. That’s something we can’t get from bones or stone tools.”

The footprints from different species displayed distinct patterns of anatomy and movement. Scientists used new 3D analysis methods to differentiate between the sets of footprints, employing cutting-edge imaging technologies to gain deeper insights into human evolution, cooperation, and competition.

Mysterious ancient human found on the roof of the world

Feibel called the discovery “a bit of serendipity,” as the fossil footprints were uncovered in 2021 during an excavation led by Louise Leakey, a third-generation paleontologist and granddaughter of Louis Leakey. The team also found fossil bones at the site.

The field team, led by Cyprian Nyete, consists primarily of skilled local Kenyans who search the landscape after heavy rains. They had been investigating fossils found on the surface when, while cleaning the top layer of a bed, Richard Loki, one of the excavators, first noticed giant bird tracks and then discovered the first hominin footprint. In response, Louise Leakey coordinated a team that excavated the footprint surface in July 2022.

Feibel highlighted that it has long been hypothesized that ‘Homo erectus’ and Paranthropus boisei coexisted. While ‘Homo erectus’, a direct ancestor of humans, survived for another million years, ‘Paranthropus boisei’ went extinct within a few hundred thousand years, and scientists are still unsure why. Both species were upright, bipedal, and agile. However, little is known about how they interacted culturally or reproductively.

DNA analysis revealed the identity of mystery fossils

The footprints are significant because they are “trace fossils”—evidence of behavior such as movement, nests, or burrows—rather than body fossils like bones and teeth. Trace fossils are important because they provide insights into behavior, whereas body fossils can be displaced by water or predators.

Feibel said, “Trace fossils cannot be moved.”

“This proves beyond any question that not only one, but two different hominins were walking on the same surface, literally within hours of each other. The idea that they lived contemporaneously may not be a surprise. But this is the first time demonstrating it. I think that’s really huge.”

Journal Reference:

1. Kevin Hatala, Neil Roach et al. Footprint evidence for locomotor diversity and shared habitats among early Pleistocene hominins. Science. DOI: 10.1126/science.ado5275