Editing Morrison Formation (section)

== Fossil content ==
{{main|Paleobiota of the Morrison Formation}}[[File:Morrison Formation near Arches.jpg|thumb|Bluish beds of the Brushy Basin Member containing alkali minerals deposited in Lake T'oo'dichi']]
{{main|List of dinosaurs of the Morrison Formation}}
Though many of the Morrison Formation fossils are fragmentary, they are sufficient to provide a good picture of the flora and fauna in the Morrison Basin during the Kimmeridgian. Overall, the [[paleoclimate|climate]] was dry, similar to a [[savanna]] but, since there were no [[angiosperm]]s ([[grass]]es, [[flower]]s, and some [[trees]]), the flora was quite different. [[Conifers]], the dominant plants of the time, were to be found with [[ginkgo]]s, [[cycad]]s, [[tree fern]]s, and [[Equisetum|horsetail rushes]]. Much of the fossilized vegetation was [[riparian]], living along the river flood plains. Along the rivers, there were [[fish]], [[frog]]s, [[salamander]]s, [[lizard]]s, [[crocodile]]s, [[turtle]]s, [[pterosaur]]s, [[crayfish]], [[clam]]s, and [[mammaliforms]].
[[File:Belt coal seam.jpg|thumb|Coal seam in the Morrison Formation, Belt, Montana]]
The [[dinosaur]]s were most likely riparian, as well.<ref name="turner-peterson-2004"/> Hundreds of dinosaur fossils have been discovered, such as ''[[Allosaurus]]'', ''[[Ceratosaurus]]'', ''[[Torvosaurus]]'', ''[[Camptosaurus]]'', ''[[Ornitholestes]]'', several [[Stegosauria|stegosaurs]] comprising at least two species of ''[[Stegosaurus]]'' and the slightly older ''[[Hesperosaurus]]'', and the early [[Ankylosauria|ankylosaurs]], ''[[Mymoorapelta]]'' and ''[[Gargoyleosaurus]]'', most notably a very broad range of [[sauropod]]s (the giants of the [[Mesozoic]] era).<ref>{{Cite journal|last1=Dodson|first1=Peter|last2=Behrensmeyer|first2=A. K.|last3=Bakker|first3=Robert T.|last4=McIntosh|first4=John S.|date=1980|title=Taphonomy and Paleoecology of the Dinosaur Beds of the Jurassic Morrison Formation|url=http://dx.doi.org/10.1017/s009483730000676x|journal=Paleobiology|volume=6|issue=2|pages=208–232|doi=10.1017/s009483730000676x|bibcode=1980Pbio....6..208D |s2cid=130686856 |issn=0094-8373|url-access=subscription}}</ref> Since at least some of these species are known to have nested in the area (''Camptosaurus'' [[embryo]]es have been discovered), there are indications that it was a good [[natural environment|environment]] for dinosaurs and not just home to migratory, seasonal populations. However, the large body mass of the sauropods has been interpreted as an adaptation to migration in times of drought.<ref name="turner-peterson-2004"/>

Sauropods that have been discovered include ''[[Diplodocus]]'' (most famously, the first nearly complete specimen of ''D. carnegii'', which is now exhibited at the [[Carnegie Museum of Natural History]], in Pittsburgh, Pennsylvania), ''[[Camarasaurus]]'' (the most commonly found sauropod), ''[[Brachiosaurus]]'', ''[[Apatosaurus]]'', ''[[Brontosaurus]]'', ''[[Barosaurus]]'', the uncommon ''[[Haplocanthosaurus]]'' and ''[[Supersaurus]]''. The very diversity of the sauropods has raised some questions about how they could all co-exist. While their body shapes are very similar (long neck, long tail, huge elephant-like body), they are assumed to have had very different feeding strategies, in order for all to have existed in the same time frame and similar environment.

=== Sites and quarries ===
[[File:Dinosaur National Monument-inside the Dinosaur Quarry building.jpeg|thumb|right|250px|Workers inside the Dinosaur Quarry building, at the [[Dinosaur National Monument]]]]
Locations where significant Morrison Formation fossil discoveries have been made include:

==== Colorado ====
[[File:FruitaPaleo.JPG|thumb|250px|Fruita Paleontological Resource Area. One of the sites is denoted by the arrow.]]
* [[Garden Park, Colorado]]: One of the three major sites excavated by the paleontologists [[Othniel Charles Marsh]] and [[Edward Drinker Cope]] during the Bone Wars in 1877, though most of the specimens were too incomplete to classify (''nomina dubia'') during the 1877-78 field seasons. The first nearly complete skeletons of ''[[Stegosaurus]], [[Ceratosaurus]],'' and ''[[Allosaurus]]'' were discovered at the site, including the type specimens of the former two and the proposed neotype of ''Allosaurus fragilis,'' in the 1883-1886 Yale field seasons.<ref>Evanoff, E., & Carpenter, K. (1998). [https://www.researchgate.net/profile/Kenneth-Carpenter-2/publication/40662156_History_sedimentology_and_taphonomy_of_Felch_Quarry_1_and_associated_sandbodies_Morrison_Formation_Garden_Park_Colorado/links/5c61c77a45851582c3e16a11/History-sedimentology-and-taphonomy-of-Felch-Quarry-1-and-associated-sandbodies-Morrison-Formation-Garden-Park-Colorado.pdf History, sedimentology, and taphonomy of felch quarry 1 and associated sandbodies, Morrison Formation, Garden Park, Colorado.] ''Modern Geology'', ''22'', 423-170.</ref>  In 1992, a specimen of ''Stegosaurus stenops'' was discovered with its [[Armour (zoology)|armor]] still in place, which confirmed that the dinosaur had two rows of plates on its back.
* [[Dry Mesa Quarry]], Colorado: A wide variety of fauna, as well as the most diverse set of dinosaurs from any Morrison Formation quarry. The first dig was in 1972, by researchers from [[Brigham Young University]]. Unique specimens include the longest dinosaur known, ''[[Supersaurus]]'', the [[wikt:chimera|chimeric]] ''[[Ultrasauros]]'', and the largest [[carnivore]] on the continent, ''[[Torvosaurus]]''.
* Fruita Paleontological Resource Area: Badlands sites located south of [[Fruita, Colorado|Fruita]], were actively worked by George Callison from California State University and the Los Angeles County Museum of Natural History. Numerous specimens of mammals, lizards, and crocodiles were found. Most recently, ''[[Fruitafossor windscheffelia]]'' and the new dinosaur ''[[Fruitadens]]'' were described from the area.
* [[Purgatoire River track site]], [[Otero County, Colorado|Otero County]].

==== Utah ====
* [[Cleveland-Lloyd Dinosaur Quarry]], Utah: First excavated by geologists from the University of Utah in the late 1920s. [[William Lee Stokes]] led an expedition from Princeton in 1939. During the Jurassic, the quarry was likely an ephemeral pond, where dinosaurs gathered and died due to severe drought.<ref>{{cite web |last1=Gates |first1=Terry |title=The Late Jurassic Cleveland-Lloyd Dinosaur Quarry as a Drought-Induced Assemblage |url=https://pubs.geoscienceworld.org/sepm/palaios/article-abstract/20/4/363/100047/The-Late-Jurassic-Cleveland-Lloyd-Dinosaur-Quarry |publisher=PALAIOS |access-date=19 June 2024}}</ref> Their bodies were reworked by seasonal flooding events, which also added other partial carcasses from elsewhere.<ref>{{cite journal |last1=Peterson |first1=Joseph E. |last2=Warnock |first2=Jonathan P. |last3=Eberhart |first3=Shawn L. |last4=Clawson |first4=Steven R. |last5=Noto |first5=Christopher R. |title=New data towards the development of a comprehensive taphonomic framework for the Late Jurassic Cleveland-Lloyd Dinosaur Quarry, Central Utah |journal=PeerJ |pages=e3368 |doi=10.7717/peerj.3368 |date=2017|volume=5 |doi-access=free |pmid=28603668 |pmc=5463971 }}</ref> ''[[Allosaurus fragilis]]'' is by far the most common dinosaur at this site, making it a model organism for studies of paleobiology in basal theropods. The rare theropods ''[[Stokesosaurus]]'' and ''[[Marshosaurus]]'' specimens were also first discovered here.
* [[Dinosaur National Monument]], Utah: First excavated by Earl Douglas working for the [[Carnegie Museum of Natural History|Carnegie Museum]] in 1909 with the purpose of finding sauropods from the Morrison Formation for public display. Monument also has fossilized dinosaurs from the [[Cedar Mountain Formation]]. 
* [[Hanksville-Burpee Quarry]], [[Hanksville, Utah|Hanksville]]

==== Wyoming ====
* [[Bone Cabin Quarry]], Wyoming
* [[Como Bluff]], Wyoming: One of the most renowned fossil sites in North America. It was first worked by Cope and particularly Marsh in 1877 and has been the source of many different sauropods and non-dinosaur species. The [[Cloverly Formation]] from the Cretaceous and some [[Triassic]] strata are also exposed at this location.
* The [[Wyoming Dinosaur Center]], [[Thermopolis, Wyoming|Thermopolis]]
* [[Ten Sleep]], including Dana Quarry from where at least 12 sauropods and theropods are recovered.<ref>Saleiro, A., & Mateus O. (2017).  Upper Jurassic bonebeds around Ten Sleep, Wyoming, USA: overview and stratigraphy. Abstract book of the XV Encuentro de Jóvenes Investigadores en Paleontología/XV Encontro de Jovens Investigadores em Paleontologia, Lisboa, 428 pp.. 357-361.</ref>