An excavation of an Early Iron Age village near Aalborg in Denmark uncovered the jaws and skull fragments from a small mammal that were morphologically identified to the genus Crocidura (white-toothed shrews). Three Crocidura species are known from prehistoric continental Europe but none of them are distributed in Scandinavia, which is why this surprising finding warranted further analyses. The bone was radiocarbon-dated to 2840-2750 calibrated years before present (cal. BP), corresponding to the Late Bronze Age and hence earlier than the Iron Age archaeological context in which it was found. Using highly optimized ancient DNA protocols, we extracted DNA from one tooth and shotgun-sequenced the sample to reconstruct a near-complete mitochondrial reference genome (17,317 bp, 32.6X coverage). Phylogenetic analyses determined this specimen as a bicoloured shrew (Crocidura leucodon) but with a phylogenetic position basal to the clade of known sequences from this species. The confirmation of Crocidura presence in Denmark by the Late Bronze Age sheds new light on the prehistoric natural history of Scandinavia. We discuss the implications of this finding from both zoo-archaeological and ecological perspectives. Furthermore, the mitochondrial genome reconstructed in this study offers a valuable resource for future research exploring the genetic makeup and evolutionary history of Eurasian shrew populations.

Between 2013 and 2021, a large-scale excavation in the south-eastern outskirts of Aalborg, Denmark, resulted in a fully excavated rural village from the Early Iron Age. One particularly unexpected zoological discovery was the identification of two jawbones and skull fragments from the white-toothed shrew genus (Crocidura) of which there are no confirmed recording from Denmark. DNA was extracted from one tooth that was removed from the jawbone, using protocols described in Allentoft et al., 2015, and Orlando et al., 2013. The DNA concentration of the library was quantified on an Agilent 2200 Tapestation, and pooled equimolarly with other libraries (from different projects) before sequenced on an Illumina NovaSeq6000 platform (150 PE).