Dinosaur National Monument

thumb|upright=1.3|Dinosaur National Monument entrance

thumb|upright=1.3|Map showing the boundaries of Dinosaur National Monument

Dinosaur National Monument is an American national monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green and Yampa rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah, north of the town of Jensen, Utah. The nearest Colorado town is Dinosaur while the nearest city is Vernal, Utah.

Originally preserved in 1915 to protect its famous Dinosaur Quarry, The Abydosaurus consists of a nearly complete skull, the lower jaw, and first four neck vertebrae. The specimen was found at the base of the Mussentuchit Member of the Cedar Mountain Formation and is the holotype for the species.

Paleontologist Earl Douglass of the Carnegie Museum discovered eight vertebrae of an Apatosaurus on August 17, 1909,

Geology

thumb|left|100px|

thumb|Multicolored beds of the Brushy Basin Member of the [[Morrison Formation]]

thumb|The Quarry Visitor Center in context to the landscape. View is from the west.

The rock layer enclosing the fossils is a sandstone and conglomerate bed of alluvial or river bed origin known as the Morrison Formation from the Jurassic Period some 150 million years old. The dinosaurs and other ancient animals were carried by the river system which eventually entombed their remains in Utah.

The pile of sediments were later buried and lithified into solid rock. The layers of rock were later uplifted and tilted to their present angle by the mountain building forces that formed the Uinta Mountains]]

The Fremont people lived in the area of what is now Dinosaur National Monument before the 14th century, with archaeological evidence dating from 200 to 1300. Archaeologists first studied and named the Fremont culture along the Fremont River in south-central Utah and have since traced it through much of the Green and Colorado River drainages.

The Fremont did not build large permanent dwellings; instead, they lived in small bands within natural shelters, such as rock overhangs or shallow caves, or small villages. They consumed plant foods, such as pine nuts, berries, and cactus fruits, as well as wild game, including mule deer, bighorn sheep, smaller mammals, and birds. They also grew corn, beans, and squash, sometimes using irrigation techniques.

Early scientific explorations

thumb|upright|Paleontologist chips rock matrix from a column of vertebrae in the Dinosaur Quarry.

The dinosaur fossil beds (bone beds) were discovered in 1909 by Earl Douglass, a paleontologist working and collecting for the Carnegie Museum of Natural History. He and his crews excavated thousands of fossils and shipped them back to the museum in Pittsburgh, Pennsylvania for study and display.

National monument

President Woodrow Wilson proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original surrounding the dinosaur quarry in Utah, to in Utah and Colorado, encompassing the river canyons of the Green and Yampa.

On the other side of the argument were powerful members of Congress from western states, who were committed to the project in order to secure water rights, obtain cheap hydroelectric power and develop reservoirs as tourist destinations. After much debate, Congress settled on a compromise that eliminated Echo Park Dam and authorized the rest of the project. The Colorado River Storage Project Act became law on April 11, 1956. It stated, "that no dam or reservoir constructed under the authorization of the Act shall be within any National Park or Monument".

Historic places

Places on the list of National Register of Historic Places include:

:Prehistoric sites

:* Castle Park Archeological District, a prehistoric residential site with inhabition during 1500 - 1000 BC and again from AD 1000 - 1899 by the Prehistoric Fremont culture, Ute and Shoshone people.

:* Mantle's Cave is a prehistoric Fremont culture residential site from 499 BC - AD 1749.

:Other sites

:*Josie Bassett Morris Ranch Complex

:* Denis Julien Inscription

:* Rial Chew Ranch Complex

:* Upper Wade and Curtis Cabin

thumb|600px|center|Green River Canyon in Dinosaur National Monument viewed west from Harper's Corner

center|thumb|600x600px|View east from Harpers Corner showing the local geology

Climate

The Dinosaur National Monument sits on a vast area of desert land in Northwestern Colorado and Northeastern Utah. Typical of high deserts, summer temperatures can be exceedingly hot, while winter temperatures can be very cold. Snowfall is common, but the snow melts rapidly in the arid and sunny climates of these states. Rainfall is very low, and the evaporation rate classifies the area as desert, even though the rainfall exceeds 10 inches.

Features

The quarry

thumb|The Quarry Exhibit Hall

thumb|Dinosaur bones on the quarry wall viewed east. This shows the bones lay three-dimensionally in the sandstone.

center|thumb|Revised quarry map combining the original Douglass map, later historical data and current bones.

alt=The Green River in Dinosaur National Monument.|thumb|The Green River in Dinosaur National Monument.

The "Wall of Bones" located within the Dinosaur Quarry building in the park consists of a steeply tilted (67° from horizontal) rock layer which contains thousands of dinosaur fossils. The preserved section is only a portion of what was originally present when Douglass made his discovery as seen on the map above. When work ceased in 1922, a portion of the quarry was left for future development. This work began as part of President Franklin Roosevelt's Civil Works Administration, which provided employment during the Depression under the Transient Relief Service and later under the Works Progress Administration. This work included constructing a road to the quarry, removal of overburden covering the bone-bearing strata, and building of a small, temporary museum. World War II interrupted work, but this was resumed in 1951 with the building of a small metal building over the east portion of the quarry to test whether bone was abundant enough to warrant a larger, more permanent building. This more permanent building was erected in the mid-1950s as part of the National Park Service Mission 66 plan. The architectural design was high controversial for its ultra-modern use of glass, steel and concrete ramp that spiraled around a cylindrical office tower. The building opened at the dedication ceremony on June 1, 1958. The design had two levels and abundant natural light so that visitors could watch technicians remove the hard rock to reveal the excavated fossil bones in-situ.

In July 2006, the Quarry Visitor Center was closed due to structural problems that since 1958 had plagued the building because it was built on unstable clay. The decision was made to build a new facility elsewhere in the monument to house the visitor center and administrative functions, making it easier to resolve the structural problems of the quarry building while still retaining a portion of the historic Mission 66 era exhibit hall. It was announced in April 2009 that Dinosaur National Monument would receive $13.1 million to refurbish and reopen the gallery as part of the Obama administration's $750 billion stimulus plan. The Park Service successfully rebuilt the Quarry Exhibit Hall, supporting its weight on 70-foot steel micropile columns that extend to the bedrock below the unstable clay. The Dinosaur Quarry was reopened in Fall 2011.

Fossils from Carnegie Quarry

thumb|Workers inside the Dinosaur Quarry building

:Now enclosed by the Dinosaur Quarry building (Gilmore (1936), Foster (2003); Good (2004).

;Planta

:Coniferophyta

;Mollusca

:Unio sp.

:Vetulonia sp.

;Reptilia

:Testudines

::Glyptops plicatus

::Dinochelys whitei

:Rhynchocephalia

::Opisthias rarus

:Pseudosuchia

::Goniopholis sp.

::Hoplosuchus kayi (h)

;Dinosauria

:Saurischia

::Theropoda

:::Ceratosaurus sp.

:::Torvosaurus sp.

:::Allosaurus fragilis

::Sauropoda

:::Apatosaurus louisae (h)

:::Barosaurus lentus

:::Camarasaurus lentus

:::Diplodocus hallorum

:::Athenar bermani (h)

:Ornithischia

::Stegosauria

:::Stegosaurus ungulatus

::Ornithopoda

:::Camptosaurus aphanoecetes (h)

:::Dryosaurus elderae (h)

:(h) = holotype

Dinosaur National Monument

Geology

Early scientific explorations

National monument

Historic places

Climate

Features

The quarry

Fossils from Carnegie Quarry

See also

References

Further reading

External links