Dinosaur National Monument | |
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IUCN category V (protected landscape/seascape) [1] | |
Location | Moffat County, Colorado and Uintah County, Utah, U.S. |
Nearest city | Vernal, Utah |
Coordinates | 40°32′N108°59′W / 40.533°N 108.983°W |
Area | 210,844 acres (853.26 km2) |
Established | October 4, 1915 [2] |
Visitors | 304,468(in 2018) [3] |
Governing body | U.S. National Park Service |
Website | Dinosaur National Monument |
Dinosaur National Monument is an American national monument located on the southeast flank of the Uinta Mountains [4] 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, [5] the monument was greatly expanded in 1938 to include its wealth of natural history. The park's wild landscapes, topography, geology, paleontology, and history make it a unique resource for both science and recreation. The park contains over 800 paleontological sites and has fossils of dinosaurs including Allosaurus , Deinonychus , Abydosaurus , and various sauropods. [5] 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 description.
Paleontologist Earl Douglass of the Carnegie Museum discovered eight vertebra of an Apatosaurus on August 17, 1909, [2] which became the first dinosaur skeleton discovered and excavated at the new Carnegie Quarry. The area around the quarry was declared a national monument on October 4, 1915. [2] The International Dark-Sky Association designated Dinosaur National Monument an International Dark Sky Park in April 2019. [6]
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 [4] during the Laramide orogeny. [5] The relentless forces of erosion exposed the layers at the surface to be found by paleontologists.
The Fremont people lived in the area of what is now Dinosaur National Monument before the 14th century, with archaeological evidence dating from c. 200 to c. 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. [8]
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. [8]
The fate of the Fremont culture is unclear. Recent theories suggest that the Fremont's lifestyle may have changed due to drought or other climate factors, dwindling natural resources, or the influence of other neighboring cultures. [8] They left evidence of their presence in the form of petroglyphs and pictographs of human and animal figures, and abstract designs. Human figures typically have trapezoidal bodies and elaborate decorations that suggest headdresses, earrings, necklaces, or shields. The animal figures include bighorn sheep, birds, snakes, and lizards. Purely abstract or geometric designs, such as circles, spirals, and various combinations of lines, are common. Many designs in the monument are accessible for close viewing, along four trails in Utah, one of which is near the visitor center, and a fifth trail in Colorado. [9]
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. [10] He and his crews excavated thousands of fossils and shipped them back to the museum in Pittsburgh, Pennsylvania for study and display.
President Woodrow Wilson proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original 80 acres (0.13 sq mi; 0.32 km2) surrounding the dinosaur quarry in Utah, to 210,844 acres (329 sq mi; 853 km2) in Utah and Colorado, encompassing the river canyons of the Green and Yampa. [2]
The plans made by the U.S. Bureau of Reclamation on a ten-dam, billion dollar Colorado River Storage Project began to arouse opposition in the early 1950s when it was announced that one of the proposed dams would be at Echo Park, in the middle of Dinosaur National Monument. The controversy assumed major proportions, dominating conservation politics for years. David Brower, executive director of the Sierra Club, and Howard Zahniser of The Wilderness Society led an unprecedented nationwide campaign to preserve the free-flowing rivers and scenic canyons of the Green and Yampa Rivers. They argued that if a national monument was not safe from development, how could any wildland be kept intact? [11]
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." [12]
Places on the list of National Register of Historic Places include: [13]
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.
Climate data for Dinosaur National Monument | |||||||||||||
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Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °F (°C) | 33.0 (0.6) | 39.0 (3.9) | 50.4 (10.2) | 60.8 (16.0) | 71.9 (22.2) | 83.2 (28.4) | 90.5 (32.5) | 87.9 (31.1) | 77.7 (25.4) | 63.6 (17.6) | 45.7 (7.6) | 34.2 (1.2) | 61.5 (16.4) |
Mean daily minimum °F (°C) | 10.8 (−11.8) | 15.2 (−9.3) | 25.0 (−3.9) | 31.8 (−0.1) | 40.5 (4.7) | 48.9 (9.4) | 56.6 (13.7) | 54.7 (12.6) | 45.5 (7.5) | 34.9 (1.6) | 23.3 (−4.8) | 12.7 (−10.7) | 33.3 (0.7) |
Average precipitation inches (mm) | 0.64 (16) | 0.56 (14) | 0.88 (22) | 1.17 (30) | 1.30 (33) | 1.06 (27) | 1.01 (26) | 0.89 (23) | 1.24 (31) | 1.46 (37) | 0.80 (20) | 0.62 (16) | 11.64 (296) |
Average snowfall inches (cm) | 9.2 (23) | 6.6 (17) | 5.9 (15) | 3.5 (8.9) | 0.7 (1.8) | 0.2 (0.51) | 0.0 (0.0) | 0.0 (0.0) | 0.2 (0.51) | 1.6 (4.1) | 4.7 (12) | 8.3 (21) | 41.1 (104) |
Source: The Western Regional Climate Center [15] |
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. [16] 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. [17] 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. [18] 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. [19] 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. [20] The Dinosaur Quarry was reopened in Fall 2011.
Apatosaurus is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax, in 1877, and a second species, A. louisae, was discovered and named by William H. Holland in 1916. Apatosaurus lived about 152 to 151 million years ago (mya), during the late Kimmeridgian to early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, New Mexico, Wyoming, and Utah in the United States. Apatosaurus had an average length of 21–23 m (69–75 ft), and an average mass of 16.4–22.4 t. A few specimens indicate a maximum length of 11–30% greater than average and a mass of approximately 33 t.
The Yampa River flows 250 miles (400 km) through northwestern Colorado, United States. Rising in the Rocky Mountains, it is a tributary of the Green River and a major part of the Colorado River system. The Yampa is one of the few free-flowing rivers in the western United States, with only a few small dams and diversions.
Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs and is the most common North American sauropod fossil. Its fossil remains have been found in the Morrison Formation, dating to the Late Jurassic epoch, between 155 and 145 million years ago.
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
Fossil Butte National Monument is a United States National Monument managed by the National Park Service, located 15 miles (24 km) west of Kemmerer, Wyoming, United States. It centers on an assemblage of Eocene Epoch animal and plant fossils associated with Fossil Lake—the smallest lake of the three great lakes which were then present in what are now Wyoming, Utah, and Colorado. The other two lakes were Lake Gosiute and Lake Uinta. Fossil Butte National Monument was established as a national monument on October 23, 1972.
Barosaurus was a giant, long-tailed, long-necked, plant-eating sauropod dinosaur closely related to the more familiar Diplodocus. Remains have been found in the Morrison Formation from the Upper Jurassic Period of Utah and South Dakota. It is present in stratigraphic zones 2–5.
Dryosaurus is a genus of an ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont. Fossils have been found in the western United States and were first discovered in the late 19th century. Valdosaurus canaliculatus and Dysalotosaurus lettowvorbecki were both formerly considered to represent species of Dryosaurus.
Jurassic National Monument, at the site of the Cleveland-Lloyd Dinosaur Quarry, well known for containing the densest concentration of Jurassic dinosaur fossils ever found, is a paleontological site located near Cleveland, Utah, in the San Rafael Swell, a part of the geological layers known as the Morrison Formation.
Brontosaurus is a genus of herbivorous sauropod dinosaur that lived in present-day United States during the Late Jurassic period. It was described by American paleontologist Othniel Charles Marsh in 1879, the type species being dubbed B. excelsus, based on a partial skeleton lacking a skull found in Como Bluff, Wyoming. In subsequent years, two more species of Brontosaurus were named: B. parvus in 1902 and B. yahnahpin in 1994. Brontosaurus lived about 156 to 146 million years ago (mya) during the Kimmeridgian and Tithonian ages in the Morrison Formation of what is now Utah and Wyoming. For decades, the animal was thought to have been a taxonomic synonym of its close relative Apatosaurus, but a 2015 study by Emmanuel Tschopp and colleagues found it to be distinct. It has seen widespread representation in popular culture, being the archetypal "long-necked" dinosaur in general media.
Marshosaurus is a genus of medium-sized carnivorous theropod dinosaur, belonging to the family Piatnitzkysauridae, from the Late Jurassic Morrison Formation of Utah and possibly Colorado.
The Dry Mesa Dinosaur Quarry is situated in southwestern Colorado, United States, near the town of Delta. Its geology forms a part of the Morrison Formation and has famously yielded a great diversity of animal remains from the Jurassic Period, among them Ceratosaurus, Supersaurus, and Torvosaurus. The quarry is found within the Uncompahgre National Forest.
Charles Whitney Gilmore was an American paleontologist who gained renown in the early 20th century for his work on vertebrate fossils during his career at the United States National Museum. Gilmore named many dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus ovatus and Thescelosaurus.
The Dinosaur Diamond is a 486-mile (782 km) scenic and historic byway loop through the dinosaur fossil laden Uinta Basin of the U.S. states of Utah and Colorado. The byway comprises the following two National Scenic Byways:
Camarasaurus lentus is an extinct species of sauropod dinosaur that lived during the Jurassic period in what is now the western United States. It is one of the four valid species of the well-known genus Camarasaurus. C. lentus fossils have been found in Wyoming, Colorado, and Utah. It is the species of Camarasaurus found in Dinosaur National Monument and the middle layers of the Morrison Formation. Camarasaurus lentus is among the best-known sauropod species, with many specimens known. A juvenile specimen of C. lentus, CM 11338, is the most complete sauropod fossil ever discovered.
The Utah Field House of Natural History State Park Museum is a museum in Vernal, Utah, United States.
Uteodon is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the late Jurassic period in what is now Uintah County, Utah. It is known from the middle of the Brushy Basin Member, Morrison Formation. The genus was named by Andrew T. McDonald in 2011 and the type species is U. aphanoecetes.
The Earl Douglass Workshop-Laboratory was used by Earl Douglass, the discoverer of the dinosaur bone deposits at the dinosaur quarry in Dinosaur National Monument, to preserve, study and prepare fossil specimens. Located next to the quarry adjacent to the Quarry Visitor Center, the workshop is a 10.5-foot (3.2 m) by 13.17-foot (4.01 m) stone shed with a flat soil roof, built into the hillside. It was built about 1920 by Carnegie Museum of Natural History personnel who were working at the site in eastern Utah.
Paleontology in Utah refers to paleontological research occurring within or conducted by people from the U.S. state of Utah. Utah has a rich fossil record spanning almost all of the geologic column. During the Precambrian, the area of northeastern Utah now occupied by the Uinta Mountains was a shallow sea which was home to simple microorganisms. During the early Paleozoic Utah was still largely covered in seawater. The state's Paleozoic seas would come to be home to creatures like brachiopods, fishes, and trilobites. During the Permian the state came to resemble the Sahara desert and was home to amphibians, early relatives of mammals, and reptiles. During the Triassic about half of the state was covered by a sea home to creatures like the cephalopod Meekoceras, while dinosaurs whose footprints would later fossilize roamed the forests on land. Sand dunes returned during the Early Jurassic. During the Cretaceous the state was covered by the sea for the last time. The sea gave way to a complex of lakes during the Cenozoic era. Later, these lakes dissipated and the state was home to short-faced bears, bison, musk oxen, saber teeth, and giant ground sloths. Local Native Americans devised myths to explain fossils. Formally trained scientists have been aware of local fossils since at least the late 19th century. Major local finds include the bonebeds of Dinosaur National Monument. The Jurassic dinosaur Allosaurus fragilis is the Utah state fossil.
Earl Douglass was an American paleontologist who discovered the dinosaur Apatosaurus, playing a central role in one of the most important fossil finds in North America. By 1922 Earl had unearthed and shipped more than 700,000 pounds of material including nearly 20 complete skeletons of Jurassic dinosaurs such as Diplodocus, Dryosaurus, Stegosaurus, Barosaurus, Camarasaurus and Brontosaurus.