Scientists have debated for years over why Bronze Age wall paintings at the ancient settlement of Akrotiri on the Greek island of Santorini depict monkeys who originated from thousands of miles away in Asia.

Some say that the artworks suggest that ancient cultures separated by great distances had clearly been trading and exchanging ideas for some time, despite all the barriers and difficulties involved.

Akrotiri was a settlement of the Minoan civilization in Bronze Age Greece that was buried by ash from a volcanic eruption which occurred around 1600 BC.

Many of the paintings on the walls of buildings there clearly show monkeys, yet there is no archaeological evidence of monkeys in Greece at the time. Most of the monkeys in the artwork have been identified as Egyptian species such as olive baboons.

This makes sense because Egypt is known to have had contact with the Minoan civilization, which was spread across several Aegean islands.

However, as a New Scientist report recently revealed, other primates depicted on the walls were grey langur monkeys, which live in southern Asia in what is now Nepal, Bhutan and India – and particularly in the Indus Valley.

Somehow, the artist who painted the monkey mural must have seen a grey langur for himself. Did Minoan Greeks visit the Indus? “I wouldn’t be surprised if someday in the future we found evidence for that kind of direct contact,” says Marie Nicole Pareja at the University of Pennsylvania in Philadelphia.

It is also possible the visit was the other way around, but again there is no evidence, she adds in her interview with the New Scientist.

Instead, it may be that Greece and Indus were connected via Mesopotamia, another Bronze Age civilization centered in what is now Iraq. Langurs may have been imported to Mesopotamia for menageries, where visiting Greeks saw them.

“It’s evidence of this far-reaching trade, these relationships with these far-flung areas,” says Pareja. Even in the Bronze Age, it seems there indeed was a great deal of exchange between these seemingly disparate and completely separate civilizations.