(CN) — Expansive grasslands with freshwater lakes once dotted the vast, dry Arabian Peninsula, inviting humans to travel the region by foot along with elephants, horses and other animals more than 100,000 years ago.
Seven footprints discovered at a site in Saudi Arabia are estimated to be about 120,000 years old according to a study published in Science Advances on Thursday. Researchers say they were made by early humans.
The footprints found in an ancient lake deposit reveal one of the earliest route Homo sapiens could have traveled during the last interglacial period.
Today, Saudi Arabia’s Al-Nefud Desert in the northern part of the peninsula is a vast, flat desert covered with windswept sand and little sign of vegetation cover.
In the western region of the desert, an international team of scientists found 376 tracks, including 7 hominin, 44 elephant, and 107 camel footprints in the lake deposit along with fossils of giant buffalo.
“From studying the lake sediments, we know that the lake was, for most of the time, large, permanent, and consisting of freshwater,” study author Mathew Stewart with Max Planck Institutes for Chemical Ecology said in an email.
“This lake, and others like it we have investigated in the area, would have provided a vital resource to animals and humans. The environment was likely an open grassland with large permanent lakes and river, perhaps something similar to modern-day East African savannas.”
There are signs that many of the tracks discovered were made as animals traveled north to south, likely indicating movements in line with seasonal shifts in rainfall. This is most evident with the elephant tracks, which are disproportionately oriented to the south according to the study.
The mere presence of elephants suggests there were freshwater sources and plant life in the modern-day Alathar lake in the Al-Nefud Desert.
Stewart said the footprints and tracks made by animals gives researchers a snapshot or glimpse into the world around this lake 120,000 years ago.
“From studying the footprints, it’s clear that humans and large mammals were utilizing this lakeside setting at a similar time,” said Stewart. “The scarcity of stone tools suggests that visitation to the lake was brief, perhaps serving as a stopping point for water and foraging.”
Previous theories about human migration to the Arabian Peninsula involved humans making their way along the coast from the African continent, but Thursday’s study provides an alternative route that humans took as they made their way east.
Researchers are confident that seven of the footprints found in their excavation are those of early humans who were on their way to a new part of the world.