Giant Ice-Age Mammals Brought to Life

12,000 years ago, giant megafauna with exotic names like the scimitar cat, dire wolf, and columbian mammoth lumbered across the North American continent. With the help of Thomas A. Demere, curator of the paleontology department at the San Diego Natural History Museum, we walk through one artist's reconstructions of just what those long gone critters may have looked like. (Sergio De la Rosa Martinez)

Mammut americanum (American mastodon) The American mastodon is an extinct, distant cousin of living elephants, Demere explains. "Unlike elephants and the closely related mammoths, mastodons probably lived along stream courses and ate tough riparian vegetation." Remains of this species were reportedly found at the Snowmass Village excavation. "The digital art image appears to be anatomically accurate and captures the essence of the animal, especially the low position of the shoulders and elongated head, Demere said. (Sergio De la Rosa Martinez)

Mammuthus columbi (Columbian mammoth) The Columbian mammoth is an extinct cousin of the living Indian elephant, and the other find at Snowmass that so excited the paleontologists from the Denver Museum of Science. "The digital art image appears to be anatomically accurate," Demere said, "and includes the large domed skull, and long tusks of this species. The small ears are in keeping with fossil evidence (frozen wooly mammoth carcasses) that suggest mammoths had small ears like living Indian elephants -- and not the much larger ears of African elephants." (Sergio De la Rosa Martinez)

Mixotoxodon larensis (notoungulate) An extinct member of a typically South American group of large-boded mammals. Mixotoxodon did migrate into North America across the Panamanian land bridge, and their fossil remains have been found as far north as Veracruz and Michoacán, Mexico -- but this odd-looking species almost certainly did not live in the region. (Sergio De la Rosa Martinez)

Homotherium serum (scimitar cat) The extinct long-toothed cat with the exotic name has been found at a number sites from Alaska to Texas, Demere said. Its fossil remains have not been reported from Snowmass, although it may have lived in the region. Demere gave this recreation his stamp of approval, "especially its hyena-like profile with low hips and taller shoulders." (Sergio De la Rosa Martinez)

Arctodus simus (short-faced bear) An extinct bear native to North America, the short-faced bear survived late into the Pleistocene -- until about 11,000 years ago, Demere said. Fossil remains of this species have not been reported from the Snowmass Village site, although it may have lived in the region. (Sergio De la Rosa Martinez)

Smilodon fatalis (saber-tooth cat) The saber-tooth cat is thought to have been an ambush (rather than pursuit) predator, Demere notes. But its fossil remains have not been reported from the Snowmass Village site -- and whether it lived in that region of North American is uncertain. (Sergio De la Rosa Martinez)

Glyptotherium "An extinct relative of the living armadillo, Glyptotherium had a covering of bony armor that formed in the dermal skin layer," Demere explains. The herbivorous mammals evolved in South America and migrated into North America during the Great American Interchange. Its fossils have been found in the American Southwest, though not necessarily as far north as Colorado. (Sergio De la Rosa Martinez)

Camelops hesternus (western camel) An extinct cousin of living Old World camels, the western camel once roamed North America and may even have traipsed through Snowmass Village. "The digital art image appears to closely resemble the living bactrian (two-humped) camel, although slightly taller and with a single hump," Demere said. (Sergio De la Rosa Martinez)

Canis dirus (dire wolf) The dire wolf is an extinct species known from Pleistocene sedimentary rocks in North America, Demere said, noting that its fossilized remains are common in the late Ice Age deposits at Rancho La Brea. (Sergio De la Rosa Martinez)