The origins of the enigmatic Falkland Islands wolf

Abstract

The origins of the extinct Falkland Islands wolf (FIW), <i>Dusicyon australis</i>, have remained a mystery since it was first recorded by Europeans in the seventeenth century. It is the only terrestrial mammal on the Falkland Islands (also known as the Malvinas Islands), which lie ∼460 km from Argentina, leading to suggestions of either human-mediated transport or overwater dispersal. Previous studies used ancient DNA from museum specimens to suggest that the FIW diverged from its closest living relative, the South American maned wolf (<i>Chrysocyon brachyurus</i>) around 7 Ma, and colonized the islands ∼330 ka by unknown means. Here we retrieve ancient DNA from subfossils of an extinct mainland relative, <i>Dusicyon avus</i>, and reveal the FIW lineage became isolated only 16 ka (8-31 ka), during the last glacial phase. Submarine terraces, formed on the Argentine coastal shelf by low sea-stands during this period, suggest that the FIW colonized via a narrow, shallow marine strait, potentially while it was frozen over.