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This walrus tusk trinket may shed light on the early days of Viking trading

Ivory was a hot commodity in Medieval Europe, where the elite had a taste for intricately carved trinkets. A new study reveals where this ivory came from, providing clues to why Vikings colonized Greenland—and why they may have eventually abandoned it.

To conduct the work, researchers ground up 23 artifacts dating from 600 to 1100 years ago. The scientists could not use such a destructive technique on carved ivory objects made from walrus tusks, which rose to fashion during a period of elephant tusk scarcity. Instead, they were able to use rostrums (pictured above), parts of the walruses’ skulls to which the tusks were often left attached during transport. The scientists then sequenced the DNA they recovered and compared it to the DNA of modern walruses as well as to 14 specimens of known origin: Four from Greenland dated to between 900 and 1400 C.E. and 10 from the Svalbard archipelago in Norway dated to the 18th and 19th centuries C.E.

The resulting family tree revealed that arctic walruses branched off into two distinct groups between 23,400 and 251,120 years ago, perhaps split up by glaciers during an ice age. The western group lived in western Greenland, the location of the Viking settlements, and northern Canada, whereas the eastern group populated eastern Greenland, Norway, and Russia. Seven of the samples belonged to animals who lived prior to 1120 C.E., and only one came from the western group. In contrast, about a dozen of the specimens dated between 1120 and 1400 C.E., 10 of which were from the western group.

Taken together, the analysis suggests walrus tusk exports didn’t take off in the first century of the Viking colony on Greenland–from 1000 to 1100 C.E. But over the next 280 years, they came to dominate the European ivory market, the team reports today in the Proceedings of the Royal Society B. This slow initial ramp-up to trading could challenge the theory that the Vikings initially colonized Greenland looking for tusks. Instead, they may have been searching for land to farm or been exiled from other parts of Europe.