Ana səhifə

A mammoth Discovery at the Florissant Fossil Beds

Yüklə 226 Kb.
ölçüsü226 Kb.
A Mammoth Discovery at the Florissant Fossil Beds

by Steven Wade Veatch, Colorado Springs Mineralogical Society

From: Pick & Pack, 7/2010

(1st Place – AFMS Original Adult Articles Advanced)

The Florissant Fossil Beds National Monument in Colorado is one of the most important late Eocene plant

and insect fossil sites in the world. The 34-million-year-old fossils range from plant and insect impressions in paper-thin shale to massive petrified tree stumps. A more recent time period is also represented in gravels that were deposited at various sites at the fossil beds. The gravels accumulated during the last Ice Age, and at one of these locations are the buried remains of a Columbian mammoth (Mammuthus colombi).

The Florissant mammoth was discovered in 1994 in a road cut near the visitor center when an intern noticed

small fragments of bone material scattered around the entrance of a rodent burrow. While many fossil discov-

eries are the result of organized scientific work, this discovery was by sheer chance.

Two years later, the area surrounding the rodent burrow was systematically excavated by the Denver Museum of Nature & Science in collaboration with the National Park Service. At the site, which is along the road to the visitor center, a grid system was laid out to record the location and depth of every bone and soil sample removed. Five two-by-two-meter squares were dug and fossils were systematically removed. Several squares in the grid layout were dug out quite deeply—close to a meter below the surface. These excavations yielded fragmentary material from a mammoth molar tooth (figures 1 and 2) and mandible (figure 3). The fossil material was carefully boxed and stored as part of the park's fossil collection. This was a landmark dig for Teller County, Colorado.

In 2004, measurements were made by the author on a detached molar fragment using a digital caliper and following the procedures outlined by Maglio (1973). By studying the thickness of the enamel and number of ridges across the tooth it was possible to identify the specimen as a Columbian mammoth rather than a woolly mammoth (M. primigenius), the latter of which was adapted to tundra conditions farther north. The author presented the findings of his research team at a scientific conference in Denver, making the Florissant mammoth part of the permanent scientific record (Veatch et. al, 2004).
The fossil material is important for several reasons: (1) it provides documentation of the presence of mammoth

fossils at Florissant; (2) this discovery at an elevation of 8,400 feet (2,560 meters) is a relatively high elevation for Columbian mammoths; and (3) the tooth was radiocarbon dated to be at least 50,000 years old. Even though this tooth is older than the reliable range for radiocarbon dating, it shows that mammoths lived at high elevations before the last glacial maximum, about 18,000 radiocarbon years ago.

The Florissant mammoth is still being studied. Sediments found with the mammoth contain pollen and spores. A team of researchers, including the author, are currently examining these microfossils and plan to publish their results soon. These scientists hope to learn more about the Florissant mammoth's environment.

References Cited:

Maglio, V.J., 1973. Origin and Evolution of the Elephantidae. Transactions of the American Philosophical

Society, New Series 63, 1-149.
Veatch, S. W., Graham, R, and Meyer, H.W., 2004. High elevation Mammuthus from the Florissant Fossil Beds National Monument, Colorado. Geological Society of America Annual Meeting, 2004.: Geological Society of America Abstracts with Programs, vol. 36, no. 5, p. 381.

Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur © 2016
rəhbərliyinə müraciət