Wednesday, July 9, 2014

[PaleoMammalogy • 2014] Early Eocene mammals from the Driftwood Creek beds, Driftwood Canyon Provincial Park, northern British Columbia, Canada

the typical Eocene paleoenvironment preserved in the Driftwood Canyon fossil beds, British Columbia, Canada.
 In the image, a Heptodon has been startled from drinking by a sound off to the right, while a small Silvacola acares on a moss-covered surface stalks the green lacewing (Pseudochrysopa harveyi) in the foreground. A water strider floats at lower left, while a march fly rests on a stalk of Equisetum at upper left. A damselfly flutters above the hedgehog at upper right under red autumn leaves of Alnus. Other plants depicted include water fern (Azolla) and waterlilies (Nuphar) (both floating), and the terrestrial plants Thuja, Metasequoia, Sassafras and saw palmettos.
Julius Csotonyi |

The early Eocene is an important time in Cenozoic history because it marked the height of global warming, coincident with significant reorganization of the mammalian biota. In North America, our understanding of mammalian diversity during this interval is largely limited to a fossil record south of the 49th Parallel. New discoveries in the early Eocene Driftwood Creek beds (Ootsa Lake Group), northern British Columbia (∼55°N) double the known diversity of Eocene mammals from this Canadian province and provide a window into the mammalian community that lived near the northernmost lake of the Okanagan Highlands, a series of Eocene lake deposits extending north-south from Republic, Washington, to Smithers, northern British Columbia. A diverse insect and fish fauna has been described from Okanagan Highlands Eocene lake shales, together with a diverse flora, interpreted as a cool upland forested landscape. We report the tapiroid cf. Heptodon and an erinaceomorph lipotyphlan Silvacola acares, gen. et sp. nov., from the Driftwood Creek beds. Presence of cf. Heptodon is consistent with the late early Eocene age of the Driftwood Creek beds determined by radiometric dating and palynology. Heptodon is otherwise known from Eocene localities in Wyoming and Colorado as well as Ellesmere Island in the High Arctic, whereas erinaceids are recorded from late Paleocene sites in Alberta, Saskatchewan, and the U.S. Western Interior and are relatively uncommon at Eocene sites in the U.S. Western Interior. Occurrence of cf. Heptodon at Driftwood Canyon supports the hypothesis proposed by others that tapiroids are proxies of densely forested habitats.

Jaelyn J. Eberle, Natalia Rybczynski & David R. Greenwood. 2014. Early Eocene mammals from the Driftwood Creek beds, Driftwood Canyon Provincial Park, northern British Columbia. Journal of Vertebrate Paleontology. 34(4); 739-746. 

New fossil discoveries: Ancient hedgehog and tapir once inhabited British Columbia