Coryphodon, the northernmost Holarctic Paleogene pantodont (Mammalia), and its global wanderings

Abstract

The pantodont Coryphodon is a frequently found component of early Eocene terrestrial faunas in North America, distributed widely from the Arctic to the Gulf Coast. The most northerly member of this genus of large herbivore is a new species that appears to be closest to the oldest known mid-latitude species, Coryphodon proterus from the Clarkforkian (Cf-2), late Paleocene, of Montana. Coryphodon is widely distributed during the early Eocene across the Holarctic, occurring also in England, Belgium, and France (MP7-9, early Eocene) on the one hand and Kazakhstan, Mongolia, and China (Gashatan-Bumbanian, late Paleocene-early Eocene, Xinjiang, Shandong, and Shanxi) on the other. Although other genera of Coryphodontidae, as well as of other pantodont families, appear to have had more sedentary habits, Coryphodon is noted for its wide distribution. Adaptations to a warm temperate northern climate, including its northern light regime, may be postulated for this genus of pantodont as well as a pattern of dispersal leading to its wide range across the Holarctic.