Continuity and Change in the Extinction Dynamics of Late Quaternary Muskox (OVIBOS): Genetic and Radiometric Evidence

Abstract Although the tundra muskox (Ovibos moschatus) is not often included in discussions of late Quaternary megafaunal extinctions, ancient DNA (aDNA) evidence indicates that this species lost a considerable portion of its genetic diversity sometime after the Last Glacial Maximum but before the mid-Holocene. Ovibos originally arose in Asia and enjoyed a Holarctic distribution during the late Pleistocene. It was previously believed that the tundra muskox disappeared in Asia near the end of that epoch. However, new evidence establishes that Ovibos expressing modern haplotypes “reappeared” for a brief period along the Arctic periphery of northeastern Asia between 3700–2800 yrbp. Where Ovibos managed to survive during the early and middle Holocene is unknown; it may have been North America or Asia (or both). In this there are certain parallels to the extinction dynamics of the woolly mammoth, Mammuthus primigenius. Most populations of woolly mammoth (including all known mainland populations) had disappeared by 9000 yrbp. However, peripheral populations on Wrangel Island in the Chukchi Sea and St. Paul Island in the Pribilofs managed to survive much later (until ca. 3700 yrbp in the case of the Wrangel population). This pattern of end-Pleistocene range collapse, followed by short-term “recovery” in the Holocene, has also been detected in the radiocarbon record for the giant Irish deer, Megaloceros giganteus. This may signify that the late Quaternary extinction process took place over a much longer interval than imagined heretofore. However, whether these megafaunal collapses occurred in truly close correlation with one another will have to be tested more rigorously with a much better 14C database than exists currently.