DOI: 10.5061/dryad.15dv41p5c
title: Data from: Greenland Norse walrus exploitation deep into the Arctic

description: Walrus ivory was a prized commodity in medieval Europe and was supplied by
 Norse hunters who expanded across the North Atlantic, establishing
 settlements in Iceland and Greenland. However, the precise sources of the
 ivory remain unclear, as well as the extent to which Norse hunted walrus
 or traded ivory with Arctic Indigenous peoples. We use high-resolution
 genomic sourcing methods to track walrus artefacts back to specific
 hunting grounds, demonstrating for the first time that Norse obtained
 ivory from the High Arctic region of the North Water Polynya, and possibly
 from the interior Canadian Arctic. This substantially expands the
 previously assumed geographic range of Norse exploitation activities,
 confirming likely encounters with Tuniit (Late Dorset Pre-Inuit) and Thule
 Inuit, as well as possible emergence of ivory exchange.
description: The biological samples (n=100) were obtained from an appropriate
 range of geographic locations and chronological intervals from different
 museum collections. Following Ruiz-Puerta et al. 2023, samples were
 extracted and sequenced in delicate ancient labs at the Globe Institute,
 University of Copenhagen. The 31 Mitogenome data from walrus ivory
 artefacts were obtained from Star et al. 2018 and Barret et al. 2022 and
 added to the Bayesian phylogenetic analysis.  All raw DNA sequence data
 was mapped to a walrus reference mitogenome (NCBI accession: NC_004029.2)
 using the PALEOMIX (v1.2.13.4) BAM pipeline.
description: # Greenland Norse walrus exploitation deep into the Arctic
 [https://doi.org/10.5061/dryad.15dv41p5c](https://doi.org/10.5061/dryad.15dv41p5c) ## Description of the data and file structure The 100 fasta sequences contain ancient, historical, and 31 artefacts of Atlantic walrus mitogenomes used to reconstruct medieval walrus ivory sourcing. This is possible using Bayesian phylogenetic analysis, in which the mitogenome from a European ivory artefact is placed within the phylogenetic clade of the walrus stock from which it was harvested. We first extracted and sequenced walrus mitogenomes in dedicated labs at the Globe Institute, University of Copenhagen, following established aDNA protocols described in Ruiz-Puerta et al. 2023. All raw DNA sequence data was mapped to a walrus reference mitogenome (NCBI accession: NC_004029.2) using the PALEOMIX (v1.2.13.4) BAM pipeline, excluding the d-loop due to poor mapping. MapDamage (v2.0.9) was used to assess the post-mortem damage and confirm the authenticity of our ancient DNA. Sample ID  (WLR, XOR, ER) refers to the laboratory identification number. Sample IDs do not refer to any geographical origin or other unique individual characteristic.  Part of the data was derived from the following sources: * Star B, Barrett JH, Gondek AT, Boessenkool S. Ancient DNA reveals the chronology of 368 walrus ivory trade from Norse Greenland. Proc R Soc B. 2018;285(1884):1–9. * Barrett JH, Khamaiko N, Ferrari G, Cuevas A, Kneale C, Hufthammer AK, et al. Walruses on the Dnieper: new evidence for the intercontinental trade of Greenlandic ivory in the Middle Ages. Proc R Soc B. 2022;289(1972):1–9.