A study of hand axes found in Spain suggests there may have been two culturally separate groups of humans living close to each other for long periods of time, quite likely representing different species. One group carried technologies recently imported from Africa, while the others were more long-term residents.
At Porto Maior in northern Spain archaeologists have found a major deposit of large cutting tools dating to 293,000-205,000 years ago. The tools have a distinctive style known as Acheulean, which is seen far more frequently in Africa and the Middle East than in Europe. The nature of the find suggests humans may have used these tools to cross the Mediterranean 300,000 years ago, but we have no idea how. It also shows the Acheulean style coexisted for a long period of time with a different style of tools, quite likely belonging to a different species of early human.
A paper in Scientific Reports notes Acheulean-style cutting tools have been found in southwestern Europe before, but never in this concentration, with 159 pieces, weighing a total of 118 kilograms (260 pounds), found very close together. Finding so many tools in close proximity is common in Africa, however. The items are also larger and heavier than those found elsewhere in Europe, while again being consistent with those on other continents.
Two theories have been used to explain the smattering of Acheulean tools previously found in Spain, Portugal, and southern France. One involves an African population crossing the Mediterranean, while the other is of an independent invention of a very similar style. Advocates of the second theory draw attention to subtle differences between the Acheulean finds in Europe and those in Africa.
The paper's authors, however, are on the African expansion side, arguing; “Any hypothetical re-invention of Acheulean technology in Europe would have occurred 1 million years after the emergence of the Acheulean in Africa in a different environmental and techno-cultural context, and most likely by a human species that was very different from the African inventor (Homo ergaster).” They see the discovery of the Porto Maior site as further evidence for their view, given the greater commonalities the site shares with African tool deposits compared to previous European finds.
Co-author Dr Martina Demuro of Adelaide University told IFLScience that other hand axes of this size have been found in Europe before, but they had been brought to the surface, for example by farmers plowing fields, preventing accurate dating.
Although the authors think it is likely the Acheulean technologies represented an intrusion into Europe from Africa, the puzzle remains as to how their makers got there. The landbridge that once existed across the Strait of Gibraltar had been submerged long before.
Either these early humans somehow walked around the Mediterranean from the east, leaving no trace until they got at least to southern France, or they found a way to sail across the perilous Strait, despite a lack of apparently suitable technology. Demuro compared the question to the one of how the “hobbits” (Homo floresiensis) reached Flores in Indonesia, which was never connected to mainland Asia, despite similarly appearing to lack the tools for true sailing.
If there were multiple species of humans living in Spain at the time, we don't even know which species they were, let alone how they interacted. However, Demuro said the variations in size probably reflected differing uses, rather than the size of the wielder's hands.