Human footprints are a source of fascination. They evoke curiosity, urging us to imagine the actions, destinations, and lives of those who made them. When fossilized, footprints offer more than imagination—they preserve moments frozen in time, giving us direct glimpses into the behavior and movement of extinct organisms. For paleontologists, these prints are invaluable, providing rare evidence of the lives of creatures from as far back as 380 million years ago, when the first four-legged animals began to walk on land.
Footprints made by ancient hominins—our evolutionary relatives—are particularly intriguing. They offer insights into how early human ancestors and their relatives moved, interacted, and adapted to their environments. Remarkable discoveries in eastern Africa have unearthed tracks that tell stories about the lives of hominins who walked upright long before our own species, Homo sapiens, emerged. Among these discoveries, new research highlights an extraordinary find: footprints from two distinct hominin species walking along a lakeshore in what is now Kenya approximately 1.5 million years ago. These tracks not only reveal the coexistence of different species but also shed light on their behaviors and environmental interactions, enriching our understanding of human evolution.
The First Fossilized Hominin Footprints in Kenya
In 1978, fossilized hominin tracks were discovered in Kenya’s Lake Turkana region. This accidental find occurred during a geological and paleontological expedition led by paleoanthropologist Anna Behrensmeyer and paleoecologist Léo Laporte. Their mission was to document fossils and environmental evidence from a time period about 1.5 million years ago.
While excavating sediment layers, the team uncovered unexpected impressions within a layer of solidified mud. Initially believed to be hippo tracks, further excavation revealed seven humanlike footprints—clear evidence of a bipedal hominin walking eastward. The tracks showed remarkable detail, including a slip into a hippo print and subsequent recovery to avoid falling. This find was awe-inspiring, connecting the researchers with a fleeting moment in the life of a hominin who lived over a million years ago.
The fossilized surface suggested that the hominin walked along the lakeshore, transitioning from softer mud to firmer ground. The environment then, as now, posed risks; slipping into a hippo track was not uncommon, as researchers noted during their modern surveys along Lake Turkana’s shore. While the 1978 tracks were extraordinary in themselves, they were only the beginning of a larger story that would unfold decades later.
A New Trackway Discovery
In 2021, another discovery in the same region added new layers to our understanding. While excavating hominin fossils, a team led by Louise Leakey found another set of footprints. These tracks, uncovered by field researcher Richard Loki, prompted collaboration with paleoanthropologists Neil Roach and Kevin Hatala, experts in analyzing ancient trackways.
Using photogrammetry—a technique for creating 3D images—the team documented the new tracks. This method preserves details of fragile sediments that cannot be safely removed for museum display. The newly uncovered prints were also dated to approximately 1.5 million years ago, though they were slightly older than the 1978 discovery, based on stratigraphic evidence.
What made these footprints particularly remarkable was that they revealed evidence of two distinct hominin species—Homo erectus and Paranthropus boisei—using the same lakeshore, likely within a short period of time. The tracks suggest that the muddy conditions that preserved them existed only briefly before being destroyed by waves or sun exposure. This close timing raises intriguing questions about the interaction, if any, between the two species.
Insights into Hominin Behavior
The new footprints confirm the coexistence of Homo erectus—our likely ancestor—and Paranthropus boisei, a distant cousin, in the same region at the same time. The Turkana Basin, where the tracks were found, was home to a diverse community of mammals, including elephants, hippos, antelope, and birds. Yet, the frequency of hominin tracks at the site is notable, particularly since other primates, such as baboons, did not leave similar evidence.
What drew these hominins repeatedly to the lake margin? The environment likely offered abundant resources, such as edible plants, freshwater bivalves, fish, birds, and reptiles. For Paranthropus boisei, whose tooth chemistry suggests a primarily herbivorous diet, the lakeshore may have been an important source of grasslike and reedlike plants. Homo erectus, with a more varied diet that included animal protein, may have exploited a wider range of resources.
The lakeshore was not without risks. Even today, Lake Turkana’s inhabitants face dangers from crocodiles and aggressive hippos. For hominins only 4 to 5 feet tall, these hazards would have been significant. Their repeated visits suggest that the benefits of the lakeshore outweighed the dangers.
The Social Lives of Early Hominins
Among the earlier discoveries at a site near Ileret, roughly 25 miles north of the recent finds, a trackway preserved the movements of at least eight hominin individuals. These prints, dated to the same general period, suggest group travel along the lake margin. The individuals were of similar size, possibly adult members of a social group. Such evidence of group behavior adds to the understanding of how early hominins interacted and organized themselves.
The coexistence of Homo erectus and Paranthropus boisei in the Turkana Basin over at least 200,000 years raises further questions. Did the two species compete for resources, or did they occupy different ecological niches? The tracks alone cannot answer these questions, but they provoke fascinating speculation about the dynamics of their shared habitat.
Preserving the Legacy of Ancient Footprints
Efforts are underway to preserve and showcase these extraordinary discoveries. At Ileret, a museum is being built by the National Museums of Kenya to protect and display excavated trackways. This facility will allow the public, including the local Daasanach community, to explore the 1.5-million-year-old footprints and learn about their significance. The museum, scheduled to open in January 2025, will include educational programs and resources aimed at engaging young people and fostering a deeper appreciation of human prehistory.
New Frontiers in Footprint Research
Fossilized footprints provide a unique perspective on the lives of ancient hominins. Unlike fossilized bones, which reveal anatomy, footprints capture behavior, movement, and interactions with the environment. Every new discovery adds a piece to the puzzle of human evolution, offering clues about how our ancestors and relatives lived, adapted, and evolved.
The recent discoveries in the Turkana Basin are a reminder of the rich and complex history of our species. As researchers continue to uncover and analyze ancient trackways, they will undoubtedly uncover new stories about the lives of our distant relatives, deepening our understanding of where we come from and how we became who we are today.