List of North American dinosaurs

This is a list of dinosaurs whose remains have been recovered from North America. North America has a rich dinosaur fossil record with great diversity of dinosaurs.

History

[edit]

The earliest potential record of dinosaurs in North America comes from rare, unidentified (possibly theropod) footprints in the Middle-Late Triassic Pekin Formation of North Carolina.[1] However, the most reliable early record of North American dinosaurs comes from fragmentary saurischian fossils unearthed from the Upper Triassic Dockum Group of Texas.[2] Later in the Triassic period, dinosaurs left more recognizable remains, and could be identified as specific genera. Examples of later Triassic North American dinosaur genera include Coelophysis, Chindesaurus, Gojirasaurus, and Tawa. Fossils of Tawa-like dinosaurs have also been found in South America, which has important indications about paleogeography. During the Early Jurassic Period, dinosaurs such as Dilophosaurus, Anchisaurus, Coelophysis (formerly known as Megapnosaurus), and the early thyreophoran Scutellosaurus lived in North America. The latter is believed to have been the ancestor of all stegosaurs and ankylosaurs. The Middle Jurassic is the only poorly represented time period in North America, although several Middle Jurassic localities are known from Mexico. Footprints, eggshells, teeth, and fragments of bone representing theropods, sauropods, and ornithopods have been found, but none of them are diagnostic to the genus level.

VOA report about North American dinosaurs

The Late Jurassic of North America, however, is the exact opposite of the Middle Jurassic. The Late Jurassic Morrison Formation is found in several U.S. states, including Colorado, Utah, Wyoming, Montana, New Mexico, Oklahoma, South Dakota, and Texas. It is notable as being the most fertile single source of dinosaur fossils in the world. The roster of dinosaurs from the Morrison is impressive. Among the theropods, Allosaurus, Saurophaganax, Torvosaurus, Ceratosaurus, Coelurus, Ornitholestes, Tanycolagreus, Stokesosaurus, and Marshosaurus are found in the Morrison. An abundance of sauropods has been found there, including Apatosaurus, Diplodocus, Barosaurus, Brachiosaurus, Camarasaurus, Brontosaurus and Amphicoelias. Three genera of stegosaurs, Alcovasaurus, Stegosaurus and Hesperosaurus, have been found there. Finally, ornithopods found in the Morrison include Camptosaurus, Dryosaurus, and Nanosaurus,

During the Early Cretaceous, new dinosaurs evolved to replace the old ones. Sauropods were still present, but they were not as diverse as they were in the Jurassic Period. Theropods from the Early Cretaceous of North America include dromaeosaurids such as Deinonychus and Utahraptor, the carnosaur Acrocanthosaurus, and the coelurosaur Microvenator. Sauropods included Astrodon, Brontomerus, and Sauroposeidon. Ornithischians were more diverse than they were in the Jurassic PerTenontosaurus,Dakotadon,hoplitosaurus are some of the ornithopods that lived during this time period. Ankylosaurs replaced their stegosaur cousins in the Cretaceous. Ankylosaurs from the Early Cretaceous of North America include Sauropelta and Gastonia. Therizinosaurs such as Falcarius are also known from the Early Cretaceous of North America.

Finally, during the Late Cretaceous Period, dinosaurs continued to diversify, with the Cenomanian stage seeing the rise of hadrosaurs such as Eolambia, and Protohadros, as well tyrannosaurs such as Moros intrepidus, which would eventually replace the carnosaurs, like Siats, as the continent’s apex predators. These groups continued to thrive into the Turonian stage, in which therizinosaurs like Nothronychus and larger ceratopsians such as Zuniceratops lived. During the Campanian stage of the Late Cretaceous, an enormous diversity of dinosaurs is known. Theropods included the tyrannosaurs Albertosaurus, Gorgosaurus, Daspletosaurus, Teratophoneus, Bistahieversor, and Appalachiosaurus, and the dromaeosaurids Dromaeosaurus, Saurornitholestes, Atrociraptor, and Bambiraptor. Ceratopsians, such as Pachyrhinosaurus, Styracosaurus, Centrosaurus, Monoclonius, Brachyceratops and Pentaceratops also existed. Among hadrosaurs, Hypacrosaurus, Gryposaurus, Kritosaurus, Parasaurolophus, Corythosaurus, Lambeosaurus and Prosaurolophus existed. During the latest Cretaceous, the Maastrichtian age, the diversity of dinosaurs saw a decline from the preceding Campanian stage. North American herbivorous dinosaurs from this time period include the titanosaur sauropod Alamosaurus, the ceratopsians Bravoceratops, Regaliceratops, Triceratops, Leptoceratops, Torosaurus, Nedoceratops, Tatankaceratops (the latter two possible species of Triceratops), and Ojoceratops, the pachycephalosaurs Pachycephalosaurus, Stygimoloch, Dracorex, and Sphaerotholus, the hadrosaurs Augustynolophus, Saurolophus and Edmontosaurus, the ornithopod Thescelosaurus the ankylosaur Ankylosaurus and the nodosaurs Denversaurus, Glyptodontopelta and Edmontonia. Predatory dinosaurs from this time period included the tyrannosaurids Tyrannosaurus, Nanotyrannus (which may just be a juvenile of the former) and Dryptosaurus, the ornithomimids Ornithomimus, Dromiceiomimus, Struthiomimus, the oviraptorids Anzu, Leptorhynchos and Ojoraptorsaurus, the troodontids Pectinodon, Paronychodon and Troodon, the coelurosaur Richardoestesia and the dromaeosaurs Acheroraptor and Dakotaraptor.

The only recorded find of a dinosaur fossil in Central America consists of a single femur discovered from Middle Cretaceous age deposits in Comayagua Department in the central part of Honduras. The fossil had been found in January, 1971 by Bruce Simonson and Gregory Horne, though it was later sent to the National Museum of Natural History, USA where it is deposited under catalogue number USNM PAL 181339. The discovery was not formally described until 1994 where it was identified as the femur of a small hadrosaur or iguanodontid, probably the former.[3] The first report of a dinosaur from Central America ever however was a newspaper article published in August of 1933 by Canada's Montreal Gazette, though the story was picked up by several American newspapers. The fossil was an isolated metatarsus that had been collected by University of Pennsylvania explorer George Mason from woods near Olanchito, Honduras, though a vertebra was also mentioned to be found by locals. The bones have since been lost and their true identity remains indeterminable.[4]

Criteria for inclusion

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List of North American dinosaurs

[edit]

Valid genera

[edit]
Name Year Formation Location Notes Images
Abydosaurus 2010 Cedar Mountain Formation (Early Cretaceous, Albian)  United States
( Utah)
Had a short domed crest on its skull similar to that of Giraffatitan
Acantholipan 2018 Pen Formation (Late Cretaceous, Santonian)  Mexico
( Coahuila)
Known to possess spike-like osteoderms
Achelousaurus 1994 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Combines long spikes on the top of its frill and a low keratinous boss over its eyes and nose
Acheroraptor 2013 Hell Creek Formation (Late Cretaceous, Maastrichtian)  United States
( Montana)
One of the geologically youngest dromaeosaurids
Acristavus 2011 Two Medicine Formation, Wahweap Formation (Late Cretaceous, Campanian)  United States
( Montana
 Utah)
Uniquely for a hadrosaurid, it lacked any ornamentation on its skull
Acrocanthosaurus 1950 Antlers Formation, Arundel Formation, Cloverly Formation, Twin Mountains Formation (Early Cretaceous, Aptian to Albian)  United States
( Maryland
 Oklahoma
 Texas
 Wyoming)
Possessed elongated neural spines that would have supported a low sail or hump in life
Acrotholus 2013 Milk River Formation (Late Cretaceous, Santonian)  Canada
( Alberta)
Had a tall, oval-shaped dome
Adelolophus 2014 Wahweap Formation (Late Cretaceous, Campanian)  United States
( Utah)
Potentially a close relative of Parasaurolophus[5]
Agujaceratops 2006 Aguja Formation (Late Cretaceous, Campanian)  United States
( Texas)
The type species was originally assigned to the genus Chasmosaurus
Ahshislepelta 2011 Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Relatively small compared to other North American ankylosaurs
Akainacephalus 2018 Kaiparowits Formation (Late Cretaceous, Campanian)  United States
( Utah)
Much of the skeleton is known, including the entirety of the skull
Alamosaurus 1922 Black Peaks Formation, El Picacho Formation, Evanston Formation?, Javelina Formation, North Horn Formation, Ojo Alamo Formation (Late Cretaceous, Maastrichtian)  United States
( New Mexico
 Texas
 Utah
 Wyoming?)
The only titanosaur confirmed to have crossed into North America. One of the largest dinosaurs known from the continent[6]
Alaskacephale 2006 Prince Creek Formation (Late Cretaceous, Maastrichtian)  United States
( Alaska)
Had an array of polygonal nodes on its squamosal
Albertaceratops 2007 Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Possessed long brow horns and a bony ridge over its nose
Albertadromeus 2013 Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
The proportions of its hindlimb suggest a cursorial lifestyle
Albertavenator 2017 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
Its discovery suggests the diversity of small dinosaurs may be higher than previously thought
Albertonykus 2009 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
May have used its specialized forelimbs to dig into tree trunks for termites[7]
Albertosaurus 1905 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
Known from more than thirty specimens, twenty-six of which are preserved together[8]
Aletopelta 2001 Point Loma Formation (Late Cretaceous, Campanian)  United States
( California)
Would have lived in present-day Mexico; its fossils were only found in California due to the shifting of tectonic plates
Allosaurus 1877 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 Utah
 Wyoming)
Multiple specimens have been discovered, making it well-known both popularly and scientifically. At least two species are known from the United States, with a third described from Portugal
Ampelognathus 2023 Lewisville Formation (Late Cretaceous, Cenomanian)  United States
( Texas)
More closely related to iguanodonts than to the morphologically similar "hypsilophodonts"[9]
Amphicoelias 1878 Morrison Formation (Late Jurassic, Tithonian)  United States
( Colorado)
Originally believed to date from the Cretaceous
Anasazisaurus 1993 Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
May have been a second species of Kritosaurus[10]
Anchiceratops 1914 Horseshoe Canyon Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Had a long, rectangular frill ringed by short, triangular spikes
Anchisaurus 1885 Portland Formation (Early Jurassic, Hettangian to Sinemurian)  United States
( Connecticut
 Massachusetts)
Some possible remains were originally misidentified as human skeletons[11]
Angulomastacator 2009 Aguja Formation (Late Cretaceous, Campanian)  United States
( Texas)
The tip of its jaw was angled 45 degrees downward, with the tooth row bent to match
Animantarx 1999 Cedar Mountain Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian)  United States
( Utah)
Its holotype was discovered during a radiological survey of a fossil site; no bones were exposed before it was excavated
Ankylosaurus 1908 Ferris Formation, Frenchman Formation, Hell Creek Formation, Lance Formation, Scollard Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta
 Saskatchewan)
 United States
( Montana
 Wyoming)
The largest and most well-known ankylosaur
Anodontosaurus 1929 Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
Originally mistakenly believed to have been toothless
Anzu 2014 Hell Creek Formation (Late Cretaceous, Maastrichtian)  United States
( Montana
 North Dakota
 South Dakota)
Large and known from considerably good remains. Preserves evidence of a tall head crest
Apatoraptor 2016 Horseshoe Canyon Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Quill knobs preserved on its ulna confirm this species had wings
Apatosaurus 1877 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 New Mexico
 Oklahoma
 Utah
 Wyoming)
Had a characteristically robust skeleton compared to other diplodocids
Appalachiosaurus 2005 Demopolis Chalk, Donoho Creek Formation?, Tar Heel Formation? (Late Cretaceous, Campanian)  United States
( Alabama
 North Carolina?
 South Carolina?)
The most complete theropod known from the eastern side of North America
Aquilarhinus 2019 Aguja Formation (Late Cretaceous, Campanian)  United States
( Texas)
May have been a semiaquatic, coastal species that used its unusual, shovel-shaped bill to scoop up vegetation in wet sediment[12]
Aquilops 2014 Cloverly Formation (Early Cretaceous, Albian)  United States
( Montana)
May have had a short horn protruding from its upper beak
Arkansaurus 2018 Trinity Group (Early Cretaceous, Aptian to Albian)  United States
( Arkansas)
State dinosaur of Arkansas. Its generic name was in use informally even before its formal description
Arrhinoceratops 1925 Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
Described as lacking a nasal horn although this is an artifact of preservation
Astrodon 1859 Antlers Formation?, Arundel Formation (Early Cretaceous, Albian)  United States
( Maryland
 Oklahoma?)
State dinosaur of Maryland
Astrophocaudia 2012 Trinity Group (Early Cretaceous, Albian)  United States
( Texas)
Known from a single partial skeleton
Atlantosaurus 1877 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado)
Potentially synonymous with Apatosaurus,[13] but a referred species may represent a separate taxon[14]
Atrociraptor 2004 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
Had a short, deep snout with enlarged teeth
Aublysodon 1868 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Only known from teeth
Augustynolophus 2014 Moreno Formation (Late Cretaceous, Maastrichtian)  United States
( California)
State dinosaur of California. Originally named as a species of Saurolophus
Avaceratops 1986 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Lacked the fenestrae in its frill, a feature shared only with Triceratops
Bambiraptor 2000 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Small but well-preserved enough to display its mix of dinosaur- and bird-like features
Barosaurus 1890 Morrison Formation (Late Jurassic, Tithonian)  United States
( South Dakota
 Utah)
Similar to Diplodocus but larger and with a longer neck
Bistahieversor 2010 Fruitland Formation, Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Analysis of its braincase suggest it behaved like tyrannosaurids despite not being a member of that family[15]
Bisticeratops 2022 Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Preserves bite marks from a tyrannosaurid
Borealopelta 2017 Clearwater Formation (Early Cretaceous, Albian)  Canada
( Alberta)
So well preserved that several osteoderms, keratin, pigments, and stomach contents are preserved in the positions they would been in while alive, without flattening or shriveling
Boreonykus 2015 Wapiti Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
One of the few dromaeosaurids known from high latitudes
Brachiosaurus 1903 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 Oklahoma
 Utah
 Wyoming)
A high browser with a tall chest and elongated forelimbs
Brachyceratops 1914 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Only known from juvenile remains. One specimen has been found to represent a subadult Styracosaurus ovatus
Brachylophosaurus 1953 Judith River Formation, Oldman Formation, Wahweap Formation? (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana
 Utah?)
Several specimens preserve extensive soft tissue remains
Bravoceratops 2013 Javelina Formation (Late Cretaceous, Campanian to Maastrichtian)  United States
( Texas)
May have had a single small horn on the top of its frill
Brontomerus 2011 Cedar Mountain Formation (Early Cretaceous, Aptian to Albian)  United States
( Utah)
Possessed an enlarged ilium which supported powerful leg muscles, which it may have used to kick away predators
Brontosaurus 1879 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Utah
 Wyoming)
Popularly associated with Apatosaurus but a 2015 study found enough differences for it to be classified as a separate genus[14]
Caenagnathus 1940 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
One of the largest known caenagnathids[16]
Camarasaurus 1877 Morrison Formation, Summerville Formation? (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 New Mexico?
 Oklahoma?
 South Dakota?
 Utah
 Wyoming)
Very common and known from multiple specimens
Camposaurus 1998 Bluewater Creek Formation (Late Triassic, Norian)  United States
( Arizona)
Potentially the oldest known neotheropod
Camptosaurus 1885 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Utah
 Wyoming)
May have fed on tough vegetation as evidenced by extensive wear frequently exhibited on its teeth[17]
Caseosaurus 1998 Dockum Group (Late Triassic, Norian)  United States
( Texas)
Possibly synonymous with Chindesaurus
Cedarosaurus 1999 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
One specimen preserves over a hundred gastroliths[18]
Cedarpelta 2001 Cedar Mountain Formation (Late Cretaceous, Cenomanian to Turonian)  United States
( Utah)
Lacked the extensive cranial ornamentation of later ankylosaurs
Cedrorestes 2007 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Known from a partial skeleton. The specific name, C. crichtoni, is named after Michael Crichton, author of Jurassic Park
Centrosaurus 1904 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Hundreds of individuals have been preserved in a single "mega-bonebed"[19]
Cerasinops 2007 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Combines features of both Asian and American basal ceratopsians
Ceratops 1888 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Although only known from a few bones, this genus is the namesake of the Ceratopsia and the Ceratopsidae
Ceratosaurus 1884 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Colorado
 Utah
 Wyoming)
Possessed a row of osteoderms running down its back
Chasmosaurus 1914 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Known from multiple remains, including various skulls
Chindesaurus 1995 Chinle Formation (Late Triassic, Norian)  United States
( Arizona)
May be a herrerasaur or a close relative of Tawa[20]
Chirostenotes 1924 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Originally known only from isolated body parts
Cionodon 1874 Denver Formation, Judith River Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
 United States
( Colorado)
Poorly known
Citipes 2020 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Some specimens were found as stomach contents of Gorgosaurus[21]
Claosaurus 1890 Niobrara Formation (Late Cretaceous, Santonian to Campanian)  United States
( Kansas)
Historically conflated with other hadrosaurs
Coahuilaceratops 2010 Cerro del Pueblo Formation (Late Cretaceous, Campanian)  Mexico
( Coahuila)
Possessed the longest brow horns of any ceratopsian
Coelophysis 1889 Chinle Formation (Late Triassic, Carnian to Rhaetian)  United States
( Arizona
 New Mexico)
Known from over a thousand specimens, making it one of the more well-known early dinosaurs. Some referred species may belong to their own genera
Coelurus 1879 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Wyoming)
Potentially an early member of the tyrannosauroid lineage[22]
Colepiocephale 2003 Foremost Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Originally described as a species of Stegoceras
Convolosaurus 2019 Twin Mountains Formation (Early Cretaceous, Aptian)  United States
( Texas)
Before its formal description, it had been informally referred to as the "Proctor Lake hypsilophodont"
Coronosaurus 2012 Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Had irregular masses of small spikes on the very top of its frill
Corythosaurus 1914 Dinosaur Park Formation, Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Possessed a semicircular crest which may have been used for vocalization
Crittendenceratops 2018 Fort Crittenden Formation (Late Cretaceous, Campanian)  United States
( Arizona)
The youngest known member of the Nasutoceratopsini
Daemonosaurus 2011 Chinle Formation (Late Triassic, Rhaetian)  United States
( New Mexico)
Unique among early dinosaurs for possessing a short snout with long teeth
Dakotadon 2008 Lakota Formation (Early Cretaceous, Barremian)  United States
( South Dakota)
Originally named as a species of Iguanodon
Dakotaraptor 2015 Hell Creek Formation (Late Cretaceous, Maastrichtian)  United States
( South Dakota)
The holotype assemblage may represent a chimera of multiple taxa[23]
Daspletosaurus 1970 Dinosaur Park Formation, Judith River Formation, Oldman Formation, Two Medicine Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana)
At least three species are known. These have been interpreted as forming an anagenetic lineage[24] but this hypothesis has been criticized[25]
Deinonychus 1969 Antlers Formation, Arundel Formation?, Cedar Mountain Formation?, Cloverly Formation (Early Cretaceous, Aptian to Albian)  United States
( Maryland?
 Montana
 Oklahoma
 Utah?
 Wyoming)
Its discovery helped researchers realize that dinosaurs were active, warm-blooded animals, kicking off the Dinosaur Renaissance
Denversaurus 1988 Lance Formation (Late Cretaceous, Maastrichtian)  United States
( South Dakota
 Wyoming)
The youngest known nodosaurid[26]
Diabloceratops 2010 Wahweap Formation (Late Cretaceous, Campanian)  United States
( Utah)
Had a distinctively short and deep skull
Diclonius 1876 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Replaced its teeth in such a way that new teeth could be used at the same time as older ones
Dilophosaurus 1970 Kayenta Formation (Early Jurassic, Sinemurian to Pliensbachian)  United States
( Arizona)
Possessed two semicircular crests running along the length of the skull
Dineobellator 2020 Ojo Alamo Formation (Late Cretaceous, Maastrichtian)  United States
( New Mexico)
Several features of its hands and feet may be adaptations for increased grip strength[27]
Diplodocus 1878 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado
 Montana
 New Mexico
 Utah
 Wyoming)
Had a long, thin tail. Popularly thought to have been used like a bullwhip[28] but it is possible that it could not handle the stress of supersonic travel[29]
Diplotomodon 1868 Hornerstown Formation?/Navesink Formation? (Late Cretaceous, Maastrichtian)  United States
( New Jersey)
Has been suggested to be non-dinosaurian
Dromaeosaurus 1922 Dinosaur Park Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
Analysis of wear on its teeth suggest it preferred tougher prey, including bone
Dromiceiomimus 1972 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
May be synonymous with Ornithomimus edmontonicus
Dryosaurus 1894 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 Utah
 Wyoming)
Remains of multiple growth stages have been found, including embryoes[30]
Dryptosaurus 1877 Hornerstown Formation?/New Egypt Formation? (Late Cretaceous, Maastrichtian)  United States
( New Jersey)
Its discovery showed that theropods were bipedal animals
Dynamoterror 2018 Menefee Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Part of the Teratophoneini, a clade of exclusively southwestern American tyrannosaurs[25]
Dyoplosaurus 1924 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
The holotype specimen preserves skin impressions[31]
Dysganus 1876 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Four species have been named, all from isolated teeth
Dyslocosaurus 1992 Lance Formation?/Morrison Formation? (Late Jurassic, Kimmeridgian?/Late Cretaceous, Maastrichtian?)  United States
( Wyoming)
Has been suggested to have four claws on its hind limbs
Dystrophaeus 1877 Morrison Formation (Late Jurassic, Oxfordian)  United States
( Utah)
Inconsistent in phylogenetic placement, although undescribed remains could further clarify its relationships
Edmontonia 1928 Dinosaur Park Formation, Horseshoe Canyon Formation, Judith River Formation? (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
 United States
( Montana?)
Possessed forward-pointing, bifurcated spikes on its shoulders
Edmontosaurus 1917 Frenchman Formation, Hell Creek Formation, Horseshoe Canyon Formation, Lance Formation, Prince Creek Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta
 Saskatchewan)
 United States
( Alaska
 Colorado
 Montana
 North Dakota
 South Dakota
 Wyoming)
Known from multiple well-preserved specimens, including a few "mummies". Several were originally assigned to their own genera and/or species
Einiosaurus 1994 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Distinguished by its forward-curving nasal horn
Eolambia 1998 Cedar Mountain Formation (Late Cretaceous, Cenomanian)  United States
( Utah)
Remains of multiple individuals are known, making up much of the skeleton
Eotrachodon 2016 Mooreville Chalk (Late Cretaceous, Santonian)  United States
( Alabama)
Had a saurolophine-like skull despite its basal position[32]
Eotriceratops 2007 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
May have been the largest known ceratopsid
Epichirostenotes 2011 Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
Its discovery allowed researchers to connect isolated caenagnathid body parts to each other
Euoplocephalus 1910 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Unusually, its palpebral bone was mobile, allowing it to be used as an eyelid[33]
Falcarius 2005 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Transitional between generalized theropods and specialized therizinosaurs
Ferrisaurus 2019 Tango Creek Formation (Late Cretaceous, Maastrichtian)  Canada
( British Columbia)
Its holotype was discovered close to a railway line[34]
Foraminacephale 2016 Dinosaur Park Formation, Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Originally assigned to three different pachycephalosaurid genera
Fosterovenator 2014 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Wyoming)
Has been variously described as a ceratosaurid, a tetanuran, or a close relative of Elaphrosaurus[35]
Fruitadens 2010 Morrison Formation (Late Jurassic, Tithonian)  United States
( Colorado)
One of the smallest known ornithischians[36]
Furcatoceratops 2023 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Preserves most of the postcranial skeleton, a rarity for ceratopsids. Remains originally identified as Avaceratops
Galeamopus 2015 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado
 Wyoming)
One specimen is nearly complete, even preserving an associated skull
Gargoyleosaurus 1998 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Wyoming)
Combines features of both ankylosaurids and nodosaurids
Gastonia 1998 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Several concentrations of fossils may suggest this taxon lived in herds[37]
Geminiraptor 2010 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
The proportions of its maxilla are similar to those of Late Cretaceous troodontids
Glishades 2010 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana
Described as a basal hadrosauroid but may in fact be a juvenile saurolophine hadrosaurid[38]
Glyptodontopelta 2000 Ojo Alamo Formation (Late Cretaceous, Campanian to Maastrichtian)  United States
( New Mexico)
Originally interpreted as possessing a flat mosaic of osteoderms similar to the shields of glyptodonts
Gojirasaurus 1997 Dockum Group (Late Triassic, Norian)  United States
( New Mexico)
May be a chimera consisting of undiagnostic theropod bones mixed with pseudosuchian vertebrae[39]
Gorgosaurus 1914 Dinosaur Park Formation, Judith River Formation?, Two Medicine Formation? (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana?)
Dozens of specimens are known
Gravitholus 1979 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Potentially synonymous with Stegoceras[40]
Gremlin 2023 Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Possessed a ridge running along the top of the skull
Gryphoceratops 2012 Milk River Formation (Late Cretaceous, Santonian)  Canada
( Alberta)
Potentially the smallest adult ceratopsian known from North America
Gryposaurus 1914 Bearpaw Formation?, Dinosaur Park Formation, Javelina Formation?, Kaiparowits Formation, Two Medicine Formation (Late Cretaceous, Santonian to Maastrichtian)  Canada
( Alberta)
 United States
( Montana
 Texas?
 Utah)
One specimen preserves impressions of a row of pyramidal scales running along its back[41]
Hadrosaurus 1858 Woodbury Formation (Late Cretaceous, Campanian)  United States
( New Jersey)
Its holotype was the first dinosaur skeleton to be mounted
Hagryphus 2005 Kaiparowits Formation (Late Cretaceous, Campanian)  United States
( Utah)
Large but only known from a single hand
Hanssuesia 2003 Dinosaur Park Formation, Judith River Formation, Oldman Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana)
One dome preserves several lesions
Haplocanthosaurus 1903 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado
 Montana?
 Wyoming)
One of the smallest sauropods of the Morrison Formation
Hesperonychus 2009 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
A common component of its habitat as indicated by the great number of its remains
Hesperornithoides 2019 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Wyoming)
Before its formal description, it had been nicknamed "Lori"
Hesperosaurus 2001 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Montana
 Wyoming)
Two morphotypes of plates are known, which has been interpreted as an indication of sexual dimorphism[42]
Hierosaurus 1909 Niobrara Formation (Late Cretaceous, Coniacian to Campanian)  United States
( Kansas)
Only known from a few bones, including osteoderms
Hippodraco 2010 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Its tooth crowns were shaped like shields
Hoplitosaurus 1902 Lakota Formation (Early Cretaceous, Barremian)  United States
( South Dakota)
Known from some osteoderms, including spikes, similar to those of Polacanthus
Huehuecanauhtlus 2012 Unnamed formation (Late Cretaceous, Santonian)  Mexico
( MichoacĂ¡n)
The southernmost non-hadrosaurid hadrosauroid known from North America[43]
Hypacrosaurus 1913 Horseshoe Canyon Formation, Two Medicine Formation (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
 United States
( Montana)
Some juveniles of this genus were originally interpreted as dwarf lambeosaurines
Hypsibema 1869 Black Creek Group, Ripley Formation (Late Cretaceous, Campanian)  United States
( Missouri
 North Carolina)
Potentially one of the largest non-hadrosaurid hadrosauroids
Hypsirhophus 1878 Morrison Formation (Late Jurassic, Tithonian)  United States
( Colorado)
Usually seen as synonymous with Stegosaurus but may be a separate genus due to differences in its vertebrae[44]
Iani 2023 Cedar Mountain Formation (Late Cretaceous, Cenomanian)  United States
( Utah)
It and possibly Tenontosaurus represent the only known rhabdodontomorphs from North America[45]
Iguanacolossus 2010 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Large and robustly built
Invictarx 2018 Menefee Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Only known from a few bones but can be distinguished from other genera by characters of its osteoderms
Issi 2021 Fleming Fjord Formation (Late Triassic, Norian)  Greenland
(Sermersooq)
Originally described as an exemplar of Plateosaurus
Jeyawati 2010 Moreno Hill Formation (Late Cretaceous, Turonian)  United States
( New Mexico)
Its postorbital bone had a rugose texture
Judiceratops 2013 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Unusually, its brow horns were teardrop-shaped in cross-section
Kaatedocus 2012 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Wyoming)
Originally interpreted as a diplodocid although study finds it to be more likely a basal dicraeosaurid[46]
Kayentavenator 2010 Kayenta Formation (Early Jurassic, Sinemurian to Pliensbachian)  United States
( Arizona)
Described in a book published through an online print-on-demand service
Koparion 1994 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Utah)
Known from a single tooth which may have come from a troodontid
Kosmoceratops 2010 Kaiparowits Formation (Late Cretaceous, Campanian)  United States
( Utah)
Possessed fifteen horns and horn-like structures, including eight hornlets folding down from the top of the frill
Kritosaurus 1910 El Picacho Formation?, Javelina Formation?, Kirtland Formation, Ojo Alamo Formation? (Late Cretaceous, Campanian)  United States
( New Mexico
 Texas)
Had an elevated nasal bone with an enlarged nasal cavity to match
Labocania 1974 La Bocana Roja Formation (Late Cretaceous, Campanian)  Mexico
( Baja California)
Robustly built with particularly strengthened frontals
Lambeosaurus 1923 Dinosaur Park Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
Possessed a hollow head crest that varied in shape between species, sexes, and ages. Most familiarly, it was hatchet-shaped in adult male L. lambei
Laosaurus 1878 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Wyoming)
Several referred specimens have been reassigned to other taxa
Latirhinus 2012 Cerro del Pueblo Formation (Late Cretaceous, Campanian)  Mexico
( Coahuila)
As described, it represented a chimera composed of lambeosaurine and saurolophine remains;[47] the exact holotypic bones belonged to a lambeosaurine[48]
Lepidus 2015 Dockum Group (Late Triassic, Norian)  United States
( Texas)
Muscle scars are preserved on the holotype bones
Leptoceratops 1914 Hell Creek Formation, Lance Formation, Scollard Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
 United States
( Montana
 Wyoming)
Analysis of its teeth show it could chew like a mammal, an adaptation to eating tough, fibrous plants[49]
Leptorhynchos 2013 Aguja Formation (Late Cretaceous, Campanian to Maastrichtian)  United States
( Texas)
Had a slightly upturned mandible similar to those of oviraptorids
Lophorhothon 1960 Black Creek Formation?, Mooreville Chalk (Late Cretaceous, Campanian)  United States
( Alabama
 North Carolina?)
Although incomplete, the holotype skull preserves evidence of a crest
Lokiceratops 2024 Judith River Formation, (Late Cretaceous, Campanian)  United States
( Montana)
A contemporary of the closely related Albertaceratops and Medusaceratops[50]
Lythronax 2013 Wahweap Formation (Late Cretaceous, Campanian)  United States
( Utah)
Already had the forward-directed orbits of derived tyrannosaurids despite its early age
Machairoceratops 2016 Wahweap Formation (Late Cretaceous, Campanian)  United States
( Utah)
Possessed two long, forward-pointing horns on the top of its frill
Magnapaulia 2012 El Gallo Formation (Late Cretaceous, Campanian)  Mexico
( Baja California)
Has been suggested to be semi-aquatic due to its tall, narrow tail[51]
Maiasaura 1979 Oldman Formation, Two Medicine Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana)
Remains of hundreds of individuals, including juveniles, eggs, and nests, have been found at a single site[52]
Malefica 2022 Aguja Formation (Late Cretaceous, Campanian)  United States
( Texas)
Its discovery suggests a greater diversity of basal hadrosaurids than previously thought
Maraapunisaurus 2018 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado)
Named from a single, lost vertebra of immense size
Marshosaurus 1976 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Colorado?
 Utah)
Potentially a close relative of South American megalosauroids[53]
Martharaptor 2012 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Had not yet acquired the robust feet of derived therizinosaurs
Medusaceratops 2010 Judith River Formation (Late Cretaceous, Campanian)  United States
( Montana)
Possessed elongated spikes curving away from the sides of its frill
Menefeeceratops 2021 Menefee Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
One of the oldest centrosaurines
Mercuriceratops 2014 Dinosaur Park Formation, Judith River Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana)
Had "wing"-like projections on its squamosal bones
Microvenator 1970 Cloverly Formation (Early Cretaceous, Albian)  United States
( Montana)
Teeth from Deinonychus have been mistakenly attributed to this species
Mierasaurus 2017 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
One of the latest-surviving turiasaurs[54]
Moabosaurus 2017 Cedar Mountain Formation (Early Cretaceous, Aptian)  United States
( Utah)
Described as a macronarian[55] but has since been reinterpreted as a turiasaur closely related to Mierasaurus[54]
Monoclonius 1876 Dinosaur Park Formation, Judith River Formation (Late Cretaceous, Campanian)  Canada
( Alberta)
 United States
( Montana)
Only known from indistinct remains of juveniles and subadults
Montanoceratops 1951 Horseshoe Canyon Formation?, St. Mary River Formation (Late Cretaceous, Maastrichtian)  Canada
( Alberta)
 United States
( Montana)
Often restored with a short nasal horn although this may be a displaced cheek horn[56]
Moros 2019 Cedar Mountain Formation (Late Cretaceous, Cenomanian)  United States
( Utah)
The proportions of its metatarsals are similar to those of ornithomimids
Mymoorapelta 1994 Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)  United States
( Colorado
 Utah)
The first ankylosaur described from the Morrison Formation
Naashoibitosaurus 1993 Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Like other kritosaurins, it possessed a nasal arch, but it was not as tall as that of Gryposaurus
Nanosaurus 1877 Morrison Formation (Late Jurassic, Oxfordian to Tithonian)  United States
( Colorado
 Wyoming)
Several referred specimens were originally assigned to other genera
Nanuqsaurus 2014 Prince Creek Formation (Late Cretaceous, Maastrichtian)  United States
( Alaska)
Described as a dwarf tyrannosaurid although undescribed remains suggest a size comparable to Albertosaurus[57]
Nasutoceratops 2013 Kaiparowits Formation (Late Cretaceous, Campanian)  United States
( Utah)
Possessed an enlarged nasal cavity and two long, curving horns similar to those of modern cattle
Navajoceratops 2020 Kirtland Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Had a distinctive notch at the very top of its frill, similar to its potential ancestor Pentaceratops[58]
Nedcolbertia 1998 Cedar Mountain Formation (Early Cretaceous, Valanginian)  United States
( Utah)
Known from three partial skeletons. The specific name, N. justinhofmanni, honors a six-year-old schoolboy who won a contest to have a dinosaur named after him
Nevadadromeus 2022 Willow Tank Formation (Late Cretaceous, Cenomanian)  United States
( Nevada)
The first non-avian dinosaur described from Nevada
Niobrarasaurus 1995 Niobrara Formation (Late Cretaceous, Coniacian to Campanian)  United States
( Kansas)
Originally mistakenly believed to have been aquatic[59]
Nodocephalosaurus 1999 Kirtland Formation (Late Cretaceous, Campanian to Maastrichtian)  United States
( New Mexico)
Closely related to Asian ankylosaurs[60]
Nodosaurus 1889 Frontier Formation (Late Cretaceous, Cenomanian to Coniacian)  United States
( Wyoming)
Its armor included banded dermal plates interspersed by bony nodules
Nothronychus 2001 Moreno Hill Formation, Tropic Shale (Late Cretaceous, Turonian)  United States
( New Mexico
 Utah)
Would have lived in the marshes and swamps[61] along the Turonian shoreline[62]
Ojoraptorsaurus 2011 Ojo Alamo Formation (Late Cretaceous, Maastrichtian)  United States
( New Mexico)
Only known from an incomplete pair of pubes
Oohkotokia 2013 Two Medicine Formation (Late Cretaceous, Campanian)  United States
( Montana)
Potentially a synonym of Scolosaurus[63]
Ornatops 2021 Menefee Formation (Late Cretaceous, Campanian)  United States
( New Mexico)
Preserves a pair of bumps on its skull which may have anchored a crest
Ornitholestes 1903 Morrison Formation (Late Jurassic, Kimmeridgian)  United States
( Wyoming)
May have possessed a sickle claw similar to those of dromaeosaurids[64]
Ornithomimus 1890 Denver Formation, Dinosaur Park Formation, Ferris Formation?, Horseshoe Canyon Formation, Kaiparowits Formation? (Late Cretaceous, Campanian to Maastrichtian)  Canada
( Alberta)
 United States
( Colorado
 Utah?
 Wyoming)
One referred specimen preserves impressions of ostrich-like feathers covering most of its body[65]
Orodromeus 1988 Two Medicine Formation (Late Cretaceous, Campanian)  United States
(