The Woodland Muskox Bootherium bombifrons (Artiodactyla, Bovidae) from Hebron, Licking County, Ohio, USA and its Paleoecology in the Great Lakes Region

Abstract

The braincase with horn cores of a male, extinct woodland muskox (Bootherium bombifrons) was recovered from a wetland near Hebron, Licking County, Ohio, in 1995. The fossil remains were preserved in sediments associated with a pro-glacial lake on the eastern margin of the Scioto lobe of the Laurentide ice sheet. An 853 cm long sediment core was analyzed, and its pollen record was used to reconstruct changes in the region’s late Pleistocene paleoecology, which was barren landscape immediately following deglaciation. This transitioned to a spruce-dominated forest, and finally a deciduous forest. While most previous records of Bootherium have been associated with spruce-dominated habitat, the Hebron muskox lived in an environment with forests dominated by deciduous trees with only minor amounts of spruce. A paleoclimatic model—based on multiple records of Bootherium—indicates the wide distribution of the species south of the maximum continental ice sheets was due to its lesser cold tolerance and higher warm temperature tolerance than the modern muskox. Based on 2 averaged direct AMS radiocarbon measurements on the muskox skull, its age is 11,086 ± 18 radiocarbon years (13,093 to 12,926 calendar years BP) making it the youngest radiocarbon dated individual of Bootherium bombifrons. This date suggests the eventual extinction of the species may be related to the decline of its preferred habitat as climates changed at the end of the Pleistocene.