Cedar Mountain

Dinosaur National Monument is a United States 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 just to the north of the town of Jensen, Utah. The nearest communities are Jensen, Utah, and Dinosaur, Colorado. The park contains over 800 paleontological sites and has fossils of dinosaurs including Allosaurus, Deinonychus, Abydosaurus (a nearly complete skull, lower jaws and first four neck vertebrae of the specimen DINO 16488 found here at the base of the Mussentuchit Member of the Cedar Mountain Formation is the holotype for the description) and various long-neck, long-tail sauropods. It was declared a National Monument on October 4, 1915. 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 Uintas during the Laramide orogeny. The relentless forces of erosion exposed the layers at the surface to be found by paleontologists. 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. President Woodrow Wilson proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original 80-acre (320,000 m2) tract surrounding the dinosaur quarry in Utah, to its present extent of over 200,000 acres (800 km²) in Utah and Colorado, encompassing the spectacular river canyons of the Green and Yampa. Though lesser-known than the fossil beds, the petroglyphs in Dinosaur National Monument are another treasure the monument holds. Due to problems with vandals, many of the sites are not listed on area maps. 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 hundreds of dinosaur fossils. The enclosing rock has been chipped away to reveal the fossil bones intact for public viewing. In July 2006, the Quarry Visitor Center was closed due to structural problems that since 1957 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. en.wikipedia.org/wiki/Dinosaur_National_Monument en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_...

Type section of the Cedar Mountain Formation, western side of Cedar Mountain, Emery County, Utah.

Type section of the Buckhorn Conglomerate, Buckhorn Reservoir, western side of Cedar Mountain, Emery County, Utah.

Morrison Formation (lower half), Jurassic-Cretacous boundary (K1 Unconformity) at red and orange paleosol, Cedar Mountain Formation (drab gray), and capping Naturita Formation. West of Dinosaur National Monument.

Brushy Basin Member of the Morrison Formation (multi-colored) unconformably overlain by the Yellow Cat Member of the Cedar Mountain Formation (drab color), Jessie's Twist, Emery County, Utah

Fossil eggs of the oospecies Macroelongatoolithus carlylei (believed to be the eggs of giant oviraptorosaurs) from the Cedar Mountain Formation of North America. At the SECU Dinolab of the North Carolina Museum of Natural Sciences

View east towards the Quarry Visitor Center at Dinosaur National Monument. The boundary between the Morrison Formation (Brushy Basin Member) and the Cedar Mountain Formation is just above the highest red bed.

Typical exposure of the Cedar Mountain Formation overlying the Morrison Formation, south of Green River Utah

This image shows the Cedar Mountain Formation near its type section at Buckhorn Reservoir, Utah. The formation is capped by a very thin bed of Dakota Formation. The Cedar Mountain Formation is a Cretaceous fluvial formation, about 98 million years old, that was deposited in the foreland basin of the Sevier Mountains just before it was flooded by the ocean to form the Western Interior Seaway.

Diagram depicting the currently named Dinosauria from the Early Cretaceous Cedar Mountain Formation of Utah. Dinosaur taxa: Cedarosaurus weiskopfae → Grand County locality.[1] Length = 15 meters.[2] Cedrorestes crichtoni → Dave's Camp Site locality.[3] Length = 6 meters.[4] Falcarius utahensis → Crystal Geyser Quarry & Suarez Site/Quarry localities.[5] Length = 5 meters.[5] Gastonia burgei → Gaston Quarry, Dalton Wells, Doelling's Bowl localities.[6] Length = 5 meters.[2] Geminiraptor suarezarum → Suarez Site/Quarry locality.[7] Length = 1.5 meters.[4] Hippodraco scutodens → Andrew's Site locality.[8] Length = 4.5 meters.[8] Iguanacolossus fortis → Don's Ridge & Doelling's Bowl localities.[8][6] Length = 9 meters.[8] Martharaptor greenriverensis → Hayden-Corbett Site.[9] Length = Extrapolated after relatives. Mierasaurus bobyoungi → Doelling’s Bowl locality.[10] Length = ∼9 meters.[10][11] Moabosaurus utahensis → Dalton Wells locality.[12] Length = 9.75 meters.[12] Nedcolbertia justinhofmanni → Dalton Wells & Gaston Quarry localities.[13] Length = ∼3 meters.[13] Utahraptor ostrommaysi → Dalton Wells, Gaston Quarry, Stikes Quarry, Utahraptor Ridge localities.[14][6] Length = 5.5 meters.[2] Yurgovuchia doellingi → Don’s Place - Doelling’s Bowl locality.[15] Length = 2.5 meters.[15] References ↑ (1999). "New sauropod from the Lower Cretaceous of Utah, USA". Oryctos 2: 21–37. ↑ a b c (2016) The Princeton Field Guide to Dinosaurs (2nd ed.), Princeton: Princeton University Press ISBN: 9780691167664. ↑ "A possible new basal hadrosaur from the Lower Cretaceous Cedar Mountain Formation of Eastern Utah" in (2007) Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs, Bloomington and Indianapolis: Indiana University Press, pp. 79–89 DOI: 10.2307/j.ctt1zxz1md.10. ISBN: 0-253-34817-X. ↑ a b (2007) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Random House ISBN: 9780375824197. Genus List for Holtz 2012 Weight Information ↑ a b (2010). "Osteology of Falcarius utahensis (Dinosauria: Theropoda): characterizing the anatomy of basal therizinosaurs". Zoological Journal of the Linnean Society 158 (1): 196–230. DOI:10.1111/j.1096-3642.2009.00464.x. ↑ a b c (2016). "The Lower Cretaceous in East-Central Utah—The Cedar Mountain Formation and its Bounding Strata". Geology of the Intermoutain West 3: 1-130. ↑ (2010). "A New Troodontid Theropod Dinosaur from the Lower Cretaceous of Utah". PLOS ONE 5 (12): e14329. DOI:10.1371/journal.pone.0014329. PMID 21179513. PMC: 3002269. ↑ a b c d (2010). "New Basal Iguanodonts from the Cedar Mountain Formation of Utah and the Evolution of Thumb-Spiked Dinosaurs". PLOS ONE 5 (11): e14075. DOI:10.1371/journal.pone.0014075. PMID 21124919. PMC: 2989904. ↑ (2012). "Martharaptor greenriverensis, a New Theropod Dinosaur from the Lower Cretaceous of Utah". PLOS ONE 7 (8): e43911. DOI:10.1371/journal.pone.0043911. PMID 22952806. PMC: 3430620. ↑ a b (2017). "Descendants of the Jurassic turiasaurs from Iberia found refuge in the Early Cretaceous of western USA". Scientific Reports 7 (1): 14311. DOI:10.1038/s41598-017-14677-2. PMID 29085006. PMC: 5662694. ↑ (2020) Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs, Princeton: Princeton University Press ISBN: 9780691202976. ↑ a b (2017). "Moabosaurus Utahensis, N. Gen., N. SP., A New Sauropod From The Early Cretaceous (Aptian) of North America". Contributions from the Museum of Paleontology, University of Michigan 32 (11): 189–243. ↑ a b (1998). "A small coelurosaurian theropod from the Yellow Cat Member of the Cedar Mountain Formation (Lower Cretaceous, Barremian) of eastern Utah". New Mexico Museum of Natural History and Science Bulletin 14: 239–248. ↑ (1993). "A large dromaeosaurid (Theropoda) from the Lower Cretaceous of Eastern Utah". Hunteria 2 (10): 1–16. ↑ a b (2012). "New Dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the Evolution of the Dromaeosaurid Tail". PLOS ONE 7 (5): e36790. DOI:10.1371/journal.pone.0036790. PMID 22615813. PMC: 3352940.

Left ilium of the camarasauromorph sauropod Brontomerus mcintoshi from the Lower Cretaceous Cedar Mountain Formation of Utah, type specimen OMNH 66430 in lateral view reconstructed from the three fragments (A), and ventral view (B).