Mammoth and Horse

Pleistocene Nevada

The Pleistocene Epoch (frequently referred to as the Ice Age) lasted from approximately 2.6 million to 11,700 years before present. During this period the region now known as western Nevada changed greatly. In wetter times, lakes formed, expanded, deepened, and sometimes merged to cover wide areas. In drier periods, the lakes shrank, became shallower, or disappeared. To survive, Pleistocene plants and animals had to adapt to the changes. As lakes expanded and dry land shrank, organisms competed for diminishing territory. When lakes receded, more dry land became available, but plants and animals then had to compete for diminishing water.

The Story of This Scene

A large Columbian mammoth bull has become trapped in a slick-sided mud hole in the clay of what had been a larger body of water. Near death from exhaustion and starvation, he was startled into what may be a final effort to escape by the approach of a male horse. Like the mammoth, the stallion came to this mud hole for much needed water. Frightened by the mammoth’s sudden movement, the horse rears in preparation to run.

The specific individuals these replicas portray lived at different times, but their species occurred together during the Pleistocene and could have been present at such a mud hole. While this scene is hypothetical, it could have occurred during a drying period when lakes were shrinking, and animals searched widely for water.

The Mammoth

This Columbian mammoth (Mammuthus columbi) is estimated to have been 50 years old when it died some 17,000 years ago. Its fossilized bones were found in the Black Rock Desert of northwestern Nevada in 1972 and were unearthed by associates and staff of the Nevada State Museum, Carson City. Careful excavation revealed this specimen was in what had been a depression along a channel of what is now the Quinn River. The sides of this hole had furrow-like gouges matching the animal’s toes suggesting this mammoth had become entrapped and died while trying vainly to climb out.

The Horse

This Ice Age horse was mature, but not very old, when it died about 25,500 years ago. It was found in 1985 near Pyramid Lake, in northwestern Nevada, approximately 50 miles southwest of the mammoth’s final resting place. It was excavated by staff and volunteers of the Nevada State Museum, Carson City with assistance from a representative of the Pyramid Lake Piute Tribe.

Paleontologists identified this specimen as Equus cf. pacificus; which is a species that died out long before Spanish Conquistadors reintroduced horses to North America. Other researchers, however, consider this animal to be Equus caballus (also called Equus ferus) which is the same species as the horses living in much of Nevada today.

Fossilization

Complete skeletons like these are rarely preserved in the fossil record. The Pleistocene experienced a unique combination of wet/lake and dry/land cycles. During drying spells these beasts were lured to their death by the temptation of water in muddy lake beds and their bones were preserved during wet periods as water rose to cover them for thousands of years. Through such preserved remains, we can glimpse examples of the last of the ancient life forms once common to the region that became Nevada. Studying such specimens helps us gain understanding of how geology, climate, and biology interact to provide living and dying conditions that contribute to the fossil record.