Footprints dating back approximately 1.4 million years have provided new insights into the social behavior and physical characteristics of an ancient hominin species in East Africa. The fossilized prints, found near Lake Turkana in Kenya, were left by a group of eight adult males belonging to the species Paranthropus boisei, revealing previously unknown aspects of their size and social structure.
Paranthropus boisei, which lived in the region until around 1.15 million years ago, is known for its robust skulls, large jaws, and teeth but is not considered a direct ancestor of modern humans. Instead, it shares a common ancestor with Homo sapiens in Australopithecus afarensis before eventually becoming extinct.
Prior fossil evidence suggested that adult males of this species were relatively short, averaging about 4 feet 6 inches in height. However, the new analysis of the footprints indicates a much larger stature, comparable to early Homo erectus individuals found nearby. Researchers estimate these Paranthropus males to have stood as tall as six feet and weighed roughly 165 pounds, demonstrating a human-like body size that contrasts with previous assumptions.
The group’s all-male composition is notable, lacking any footprints attributed to females or juveniles. This absence points to a possible division of labor or sex segregation in certain activities among early hominin groups. Modern ape societies often have males forming cooperative coalitions to defend territory, patrol boundaries, and hunt, a behavior that may have parallels in Paranthropus social organization.
Dr. Neil Roach, a Harvard University researcher and co-author of the study, suggested the group’s all-male travel could hint at a complex social structure. He explained that males might have lived in larger groups where intra-sex competition for mates was balanced by cooperation to enhance survival in a hazardous environment.
The footprints were studied in detail by an international team, including Dr. Kevin Hatala from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. The findings were published in the Proceedings of the National Academy of Sciences, contributing to a growing understanding of how early hominin group dynamics and physical characteristics evolved in response to environmental challenges and social needs.