Misplaced Pages

Jurassic National Monument

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
(Redirected from Cleveland Lloyd Quarry)
This article uses bare URLs, which are uninformative and vulnerable to link rot. Please consider converting them to full citations to ensure the article remains verifiable and maintains a consistent citation style. Several templates and tools are available to assist in formatting, such as reFill (documentation) and Citation bot (documentation). (September 2022) (Learn how and when to remove this message)
Jurassic National Monument
Cleveland-Lloyd Dinosaur Quarry Visitor Center
Map showing the location of Jurassic National MonumentMap showing the location of Jurassic National MonumentMap of Utah
LocationEmery County, Utah
Nearest cityCleveland
Coordinates39°19′22″N 110°41′22″W / 39.32282°N 110.68951°W / 39.32282; -110.68951
Governing bodyBureau of Land Management
www.blm.gov/wo/st/en/res/Education_in_BLM/Learning_Landscapes/For_Travelers/go/geology/cleveland-lloyd.html
U.S. National Natural Landmark
Designated1965
Skull cast of Allosaurus fragilis, assembled from moulded bones found at Cleveland-Lloyd Dinosaur Quarry. The skull is now at the Palaeontological Museum, Munich (Germany).
Jurassic National Monument landscape, 2019
Exhibit buildings and visitor center at Jurassic National Monument. View is towards the west.

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.

Well over 15,000 bones have been excavated from this Jurassic excavation site and there are many thousands more awaiting excavation and study. It was designated a National Natural Landmark in October 1965. The John D. Dingell, Jr. Conservation, Management, and Recreation Act, signed into law by President Donald Trump on March 12, 2019, named it as a national monument.

All of these bones, belonging to different species, are found disarticulated and indistinctly mixed together. It was hypothesized by Peter Dodson in 1980 that this strong concentration of mixed fossilized bones was due to a "predator trap", however it is more likely that this site was actually caused by an extreme drought. No strict scientific consensus currently exists.

Visiting

The visitor center is administered by the Bureau of Land Management. There is a skeleton reconstruction of an adult Allosaurus (and other bones) on display in the visitor center, along with many other exhibits. A renovated and expanded quarry visitor center was dedicated on April 28, 2007. The visitor center is open seasonally with variable hours.

History

The quarry was found by sheepherders and cattlemen as they drove their animals through the area during the late 19th century. In 1927, the Department of Geology at the University of Utah, under the direction of Chairman F.F. Hintze, visited the area and collected 800 bones. In 1939-41 a field party of Princeton University, led by William Lee Stokes (1915–1994, known as the "Father of Utah geology"), came on site to extensively dig up specimens. Because of the proximity to Cleveland, Utah, and because these expeditions were financed by Malcolm Lloyd, the site was later known as the Cleveland-Lloyd Quarry. In three summers, the 1939-1941 Princeton expeditions collected 1,200 bones. A part of these bones was sent to Princeton and eventually the bones were sorted to mount a complete composite skeleton of Allosaurus, but World War II broke out and the skeleton was not mounted and exhibited in the University until February 1961. This Allosaurus skeleton, still nowadays on display at Guyot Hall, in the campus of New Jersey, is most likely the first Allosaurus skeletal mount obtained from the quarry. In the meantime, and because excavations had been interrupted by the war, work started again in 1960, when young paleontologist James Henry Madsen Jr. (1932-2009) was hired within the University of Utah to assist William Lee Stokes with the excavations.

As of 1960 Stokes and Madsen founded the "University of Utah Cooperative Dinosaur Project", with funds of the University of Utah. This project granted casts or specimens of dinosaurs to museums and institutions from the US but also from countries all around the world, in exchange of financial and excavation assistance. The project continued until 1976 when the University of Utah interrupted the funding. Madsen managed to continue excavating the quarry by means of a private company he founded the same year, Dinolab, intended to sell casts of dinosaur skeletons to museums, institutions and private buyers. Before that, in 1974, a new dinosaur had been described by Madsen, then assistant research professor of geology and geophysics in the University of Utah. He named it Stokesosaurus clevelandi, honouring his mentor, professor William Lee Stokes. In 1976, another new dinosaur was described from fossils found in the quarry by Madsen. He named it Marshosaurus bicentesimus, honouring American paleontologist Othniel Charles Marsh (1831-1899). In 1987, Brigham Young University paleontologists excavated a fossil dinosaur egg, at the time the oldest such egg ever found.

Over the years, excavations led by the University of Utah and the Natural History Museum of Utah have resulted in the collection of more than 12,000 fossil bones from the quarry. While most of the original fossils are currently housed at the Natural History Museum of Utah, many skeletons reproduced from Cleveland-Lloyd dinosaur remains are now on exhibit in more than 65 museums worldwide. Original specimens from the quarry remain on public exhibit in Utah at the Natural History Museum of Utah in Salt Lake City, the Utah State University Eastern Prehistoric Museum in Price and the Earth Science Museum at Brigham Young University in Provo.

The U.S. Department of the Interior, Bureau of Land Management (BLM) opened a visitor center at the Cleveland-Lloyd Dinosaur Quarry in 1968. This was the first-ever BLM visitor center. On April 28, 2007 a new, larger facility was dedicated that has updated exhibits. The new visitor center generates its own electricity from rooftop solar panels.

Early in 2019, the quarry reached the official status of "national monument" under the name of "Jurassic National Monument".

Geology

Map showing the thousands of dinosaur bones excavated at the Cleveland-Lloyd Dinosaur Quarry at the Jurassic National Monument.

The Cleveland-Lloyd Dinosaur Quarry of east central Utah has produced one of the most prolific dinosaurs bone assemblages in the Upper Jurassic beds of North America. The quarry is part of the Brushy Basin Member of the Morrison Formation. The fossil deposit consists of a calcareous smectitic mudstone which accumulated on the floodplain of an anastomosing river system. An anastomosing river system consists of multiple interconnected channels confined by prominent levees separated by interchannel topographic lows. The depositional environment of the quarry mudstone was an interchannel seasonal accumulation of clay nested in a topographic low between channel levees called a floodpond.

Dinosaurs came to the floodpond during a drought in search of water, with the herbivores and smaller carnivores falling prey to the large theropods present for food. As the drought continued, the dinosaurs present dwindled until eventually adult Allosaurus would resort to cannibalizing juvenile individuals for survival. The preserved fauna consists of almost all dinosaurs with the majority being carnivorous dinosaurs including Allosaurus (material from at least 44 individuals make up almost 67% of all remains), Torvosaurus (1), Ceratosaurus (1), Stokesosaurus (2), Marshosaurus (2), and a Tanycolagreus (1). Herbivorous dinosaurs include Camarasaurus (3), Diplodocus (1), Barosaurus (1), Apatosaurus (1), Camptosaurus (5), and Stegosaurus (4). Non-dinosaurian fauna include a crocodile (Goniopholis), 2 turtles (Glyptops), 4 genera of gastropoda (snails), and 4 genera of charophyte.

For a long time, the atypical predator/prey ratio (3:1) represented at the quarry was thought to be the result of possible pack hunting tendencies of Allosaurus. The high percentage of smaller individual allosaurs suggests that juveniles coordinated their efforts to capture and kill prey. They may have followed their prey into the floodpond and subsequently became mired themselves. The close spatial proximity of skull elements (most belonging to Allosaurus) seemingly supported this hypothesis. Larger individual theropods almost certainly became mired while attempting to scavenge the carcasses of other entrapped dinosaurs (Richmond and Morris, 1996). However, more recent studies suggest that the mass deaths were in fact a result of a drought, and not a predator trap. One comparison with the La Brea Tar Pits suggests that multiple, non-migratory groups of Allosaurus may have come to the area looking to find water, dying due to the harsh conditions and perhaps from diseases caused by drinking contaminated water due to rotting carcasses and feces being present. The evidence for this theory is strengthened by the fact that a large proportion of the Allosaurus specimens are juveniles, but until more evidence is recovered, this cannot yet be vindicated.

Paleofauna

Fossil taxa discovered at the Cleveland-Lloyd site include:

Plantae

Mollusca

Gastropoda

Chelonii

Dinosauria

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Ornithischians

Ornithischians reported from the Cleveland-Lloyd Quarry
Genus Species Notes Images

Camptosaurus

C. dispar

Stegosaurus

Stegosaurus

S. stenops

The largest ornithischian reported from the quarry

Sauropods

Sauropods reported from the Cleveland-Lloyd Quarry
Genus Species Notes Images

Apatosaurus

A. sp

Apatosaurus
Camarasaurus

Barosaurus

B. sp

Camarasaurus

C. lentus

3 skeletons were unearthed

Diplodocus

D. sp

Theropods

Theropods reported from the Cleveland-Lloyd Quarry
Genus Species Amount Notes Images

Allosaurus

A. fragilis

44 - 60

The largest theropod reported from the quarry

Allosaurus mounted skeleton
Tanycolagreus

Ceratosaurus

C. dentisulcatus (may just represent the adult form of C. nasicornis)

1

The rarest theropod species in the quarry

Marshosaurus

M. bicentesimus

2

Stokesosaurus

S. clevelandi

2

The largest coelurosaur reported from the quarry

Tanycolagreus

T. topwilsoni

1

Remains originally referred to Stokesosaurus clevelandi.

Torvosaurus

T. tanneri

1

See also

References

  1. "National Natural Landmarks - National Natural Landmarks (U.S. National Park Service)". www.nps.gov. Retrieved 2019-03-30. Year designated: 1965
  2. "Text - S.47 - John D. Dingell, Jr. Conservation, Management, and Recreation Act". United States Congress. 2019-03-12. Retrieved 2019-03-12.
  3. Gates, Terry A. (2005) The Late Jurassic Cleveland-Llyod Dinosaur Quarry as a Drought-Induced Assemblage
  4. https://commons.lib.niu.edu/bitstream/handle/10843/21602/Reddick_niu_0162M_13209.pdf?sequence=1&isAllowed=y Archived 2021-01-06 at the Wayback Machine
  5. "Cleveland Lloyd Dinosaur Quarry". Utah.com. Archived from the original on 2015-09-24. Retrieved 2017-06-16.
  6. ^ Madsen, James H (1976). Allosaurus fragilis: a revised osteology. Salt Lake City: Utah Geological and Mineral Survey, Utah Dept. of Natural Resources.
  7. "USU Eastern Prehistoric Museum". Archived from the original on 2016-08-26. Retrieved 2016-09-20.
  8. Borunda, Alejandra (February 27, 2019). "10 places that will be protected by Congress's new public lands bill". National Geographic. Archived from the original on August 4, 2019. Retrieved October 28, 2022.
  9. Gammon, Kathleen (March 12, 2019). "Trump approves five national monuments – from black history to dinosaur bones". The Guardian. Retrieved October 28, 2022.
  10. Farlow, James O.; Coroian, Dan; Currie, Phillip J.; Foster, John R.; Mallon, Jordan C.; Therrien, Fraçois (July 11, 2022). "Dragons" on the landscape: Modeling the abundance of large carnivorous dinosaurs of the Upper Jurassic Morrison Formation (USA) and the Upper Cretaceous Dinosaur Park Formation (Canada)
  11. Gates, Terry A. (2005) The Late Jurassic Cleveland-Llyod Dinosaur Quarry as a Drought-Induced Assemblage
  12. https://commons.lib.niu.edu/bitstream/handle/10843/21602/Reddick_niu_0162M_13209.pdf?sequence=1&isAllowed=y Archived 2021-01-06 at the Wayback Machine

Other sources

  • Stokes, William J. (1945). A new quarry for Jurassic dinosaurs. Science. 101 (2614): 115–117. Bibcode:1945Sci...101..115S
  • Stokes, W. L. (1985). The Cleveland-Lloyd Dinosaur Quarry: Window to the Past. U. S. Government Printing Office.
  • Richmond, D. R. and Morris, T. H. (1996). The dinosaur death trap of the Cleveland-Lloyd Dinosaur Quarry, Emery County, Utah, in Morales, M., ed., The Continental Jurassic: Museum of Northern Arizona Bulletin 60, pp. 533–545.
  • Joseph E. Peterson, Jonathan P. Warnock, Shawn L. Eberhart, Steven R. Clawson & Christopher R. Noto (2017). New data towards the development of a comprehensive taphonomic framework for the Late Jurassic Cleveland-Lloyd Dinosaur Quarry, Central Utah. PeerJ 5:e3368, doi: http://doi.org/10.7717/peerj.3368
  • Hunt, Adrian P; Lucas, Spencer G.; Krainer, Karl; Spielmann, Justin (2006). The taphonomy of the Cleveland-Lloyd Dinosaur Quarry, Upper Jurassic Morrison Formation, Utah: a re-evaluation. In Foster, John R.; Lucas, Spencer G. Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin, 36. Albuquerque, New Mexico: New Mexico Museum of Natural History and Science. pp. 57–65.
  • Loewen, Mark A. (2003). Morphology, taxonomy, and stratigraphy of Allosaurus from the Upper Jurassic Morrison Formation. Journal of Vertebrate Paleontology. 23 (3, Suppl.): 72A. doi:10.1080/02724634.2003.10010538

External links

Protected areas of Utah
Federal
National Parks
NPS National Monuments
National Historic Parks
National Recreation Areas
National Historic Trails
National Forests
Forest Service areas
National Wildlife Refuges
National Conservation Areas
BLM National Monuments
U.S. Wilderness Areas
Wild and Scenic Rivers
State
State Parks
Northern Region
State Parks
Central Region
State Parks
Southern Region
National monuments of the United States
National Park Service
US Forest Service
Bureau of
Land Management
Other (FWS, DOE,
AFRH, NOAA, USAF, Army)
Full Detailed List
National Natural Landmarks in the United States
Categories: