Scientists working on the Greek island of Crete have found distinctly human-like footprints that are 5.7 million years old — a discovery that is challenging accepted theories of human evolution because they date back long before human ancestors are thought to have left Africa.
The footprints, found embedded in rock in an area called Trachilos in western Crete, show that the creature was bipedal, had five toes, and sported an especially human-like big toe that is similar to those of modern humans in size, shape, and position.
The research is published in the journal Proceedings of the Geologists’ Association.
“Human feet have a very distinctive shape, different from all other land animals,” wrote Uppsala University, in a statement. “The combination of a long sole, five short forward-pointing toes without claws, and a hallux (“big toe”) that is larger than the other toes, is unique.”
By contrast, the 3.7 million-year-old Laetoli footprints from Tanzania, believed to have been made by Australopithecus, lack arches and have narrower heels than modern humans, while the 4.4 million-year-old Ardipithecus ramidus from Ethiopia has a more ape-like foot.
“What makes this controversial is the age and location of the prints,” says co-author Prof. Per Ahlberg of Uppsala University, in the statement.
When the Trachilos footprints were made, during the late Miocene, Crete was still attached to the Greek mainland and savannah-like environments stretched from North Africa around the eastern Mediterranean.
“This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate,” says Ahlberg. “Whether the human origins research community will accept fossil footprints as conclusive evidence of the presence of hominids in the Miocene of Crete remains to be seen.”