North Dakota Stratigraphy Archaeotherium ROCK ROCK UNIT COLUMN PERIOD EPOCH AGES MILLIONS OF YEARS AGO Common Name: Holocene Oahe .01 Pig-like mammal Coleharbor Pleistocene QUATERNARY Classification: 1.8 Pliocene Unnamed 5 Miocene Class: Mammalia 25 Arikaree Order: Artiodactyla Family: Entelodontidae Brule Oligocene 38 South Heart Skull of the giant pig-like mammal, Archeotherium. 400 mm long. Chadron Chalky Buttes Oligocene Brule Formation. Stark County. North Dakota State Camels Butte Eocene Golden 55 Valley Bear Den Fossil Collection. Sentinel Butte Description: TERTIARY Archaeotherium was similar in appearance to the living warthog and grew to lengths of about 4 feet. It had an elongate skull with unusual protrusions of bone on the lower jaws beneath the eyes. Bullion Paleocene Creek These boney knobs probably provided anchors for the powerful jaw muscles. Archaeotherium mostly ate roots and tubers but Slope with its powerful jaws and teeth could eat most anything, even Cannonball carrion, like modern pigs. The strong shoulder and neck muscles suggest that these animals spent much of their time rooting and Ludlow 65 grubbing in the ground. Large olfactory lobes indicate that they Hell Creek had a keen sense of smell. Fox Hills ACEOUS Pierre CRET 84 Niobrara Carlile Carbonate Calcareous Shale Claystone/Shale Siltstone Sandstone Sand & Gravel Mudstone Lignite Glacial Drift Archaeotherium. Painting courtesy of Simon and Schuster Publishing Company. Locations where fossils have been found ND State Fossil Collection Prehistoric Life of ND Map North Dakota Geological Survey Home Page.