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

Summarize

Perspective

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 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

The genus must appear on the List of dinosaur genera.
At least one named species of the creature must have been found in North America.
This list is a complement to Category:Mesozoic dinosaurs of North America.

List of North American dinosaurs

Valid genera

More information Name, Year ...

Name	Year	Formation	Location	Notes
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
Ahvaytum	2025	Popo Agie Formation (Late Triassic, Carnian)	United States ( Wyoming)	One of the oldest North American dinosaurs
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, Campanian)	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 that 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 feeding on 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 Oklahoma Utah Wyoming)	Multiple specimens have been discovered, making it well-known both popularly and scientifically. At least three species are known from the United States, in addition to one 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° at its anterior end, 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	Dinosaur Park Formation, 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 genus 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	Blufftown Formation?, Demopolis Chalk, Donoho Creek Formation?, Ripley Formation?, Tar Heel/Coachman Formation? (Late Cretaceous, Campanian)	United States ( Alabama Georgia (U.S. state)? 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
Ardetosaurus	2024	Morrison Formation (Late Jurassic, Kimmeridgian)	United States ( Wyoming)	The holotype specimen was damaged by a museum fire
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	1865	Antlers Formation?, Arundel Formation (Early Cretaceous, Albian)	United States ( Maryland Oklahoma?)	State dinosaur of Maryland
Astrophocaudia	2012	Paluxy Formation (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, Kimmeridgian to 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 suggests it behaved like tyrannosaurids despite likely 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 have 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)	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)	Suggested to have had a single small horn on the top of its frill but this may be inaccurate
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 to Tithonian)	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, Kimmeridgian 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	Tecovas Formation (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 ankylosaurids
Cedrorestes	2007	Cedar Mountain Formation (Early Cretaceous, Valanginian)	United States ( Utah)	Known from a partial skeleton. The specific name, crichtoni, honors Michael Crichton, author of Jurassic Park and The Lost World
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 North 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, Kimmeridgian 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 Huerta Formation (Late Cretaceous, Maastrichtian)	Mexico ( Coahuila)	Possessed brow horns comparable in size to those of Triceratops and Torosaurus
Coahuilasaurus	2024	Cerro del Pueblo Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	Identified as a specimen of Kritosaurus^[22] before receiving its own genus name^[23]
Coelophysis	1889	Chinle Formation (Late Triassic, Norian)	United States ( Arizona New Mexico)	Known from over a thousand specimens, making it one of the most 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^[24]
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 hypsilophodontid"
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, Norian to 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^[25]
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^[26] but this hypothesis has been criticized^[27]
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^[28]
Diabloceratops	2010	Wahweap Formation (Late Cretaceous, Campanian)	United States ( Utah)	Had a distinctively short, 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 Toarcian)	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^[29]
Diplodocus	1878	Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian?)	United States ( Colorado Montana New Mexico Utah Wyoming)	Had a long, thin tail. Popularly thought to have been used like a bullwhip^[30] but it is possible that it could not handle the stress of supersonic travel^[31]
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, Hell Creek Formation?, Horseshoe Canyon Formation?, Prince Creek Formation? (Late Cretaceous, Campanian to Maastrichtian?)	Canada ( Alberta) United States ( Alaska? South Dakota?)	Analysis of wear on its teeth suggests 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 specimens in embryonic age^[32]
Dryptosaurus	1877	Navesink 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 tyrannosaurids exclusively known from southwestern North America^[27]
Dyoplosaurus	1924	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	The holotype specimen preserves skin impressions^[33]
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 hindlimbs
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
Eoneophron	2024	Hell Creek Formation (Late Cretaceous, Maastrichtian)	United States ( South Dakota)	Smaller than the contemporary Anzu
Eotrachodon	2016	Mooreville Chalk (Late Cretaceous, Santonian)	United States ( Alabama)	Had a saurolophine-like skull despite its basal position^[34]
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^[35]
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^[36]
Fona	2024	Cedar Mountain Formation (Late Cretaceous, Cenomanian)	United States ( Utah)	Possibly a semi-fossorial animal based on the related Oryctodromeus^[37]
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, Kimmeridgian to Tithonian)	United States ( Wyoming)	Has been variously described as a ceratosaurid, a tetanuran or a close relative of Elaphrosaurus^[38]
Fruitadens	2010	Morrison Formation (Late Jurassic, Tithonian)	United States ( Colorado)	One of the smallest known ornithischians^[39]
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^[40]
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^[41]
Glyptodontopelta	2000	Ojo Alamo Formation (Late Cretaceous, Maastrichtian)	United States ( New Mexico)	Originally interpreted as possessing a flat mosaic of osteoderms similar to the shields of glyptodonts
Gojirasaurus	1997	Bull Canyon Formation (Late Triassic, Norian)	United States ( New Mexico)	May be a chimera consisting of undiagnostic theropod bones mixed with pseudosuchian vertebrae^[42]
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^[43]
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^[44]
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, Oldman 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^[45]
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 ( Michoacán)	The southernmost non-hadrosaurid hadrosauroid known from North America^[46]
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	Marshalltown Formation?, Ripley Formation, Tar Heel/Coachman Formation (Late Cretaceous, Campanian)	United States ( Missouri New Jersey? 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^[47]
Iani	2023	Cedar Mountain Formation (Late Cretaceous, Cenomanian)	United States ( Utah)	Represents the family Tenontosauridae, a clade of North American rhabdodontomorphs^[48]
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 to Coniacian)	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 one study finds it to be more likely a basal dicraeosaurid^[49]
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 to Maastrichtian?)	United States ( New Mexico Texas?)	Had an elevated nasal bone with an enlarged nasal cavity to match
Labocania	1974	Cerro del Pueblo Formation, La Bocana Roja Formation (Late Cretaceous, Cenomanian? to Campanian)	Mexico ( Baja California Coahuila)	The description of the second species, L. aguillonae, suggests a position within the tyrannosaurid clade Teratophoneini^[50]
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.^[51] The exact holotypic bones belonged to a lambeosaurine^[52]
Lepidus	2015	Colorado City Formation (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 shows it could chew like a mammal, an adaptation to eating tough, fibrous plants^[53]
Leptorhynchos	2013	Aguja Formation (Late Cretaceous, Campanian)	United States ( Texas)	Had a slightly upturned mandible similar to those of oviraptorids
Lokiceratops	2024	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Unusually for a ceratopsid, its frill ornamentations were bilaterally asymmetrical. Closely related to Albertaceratops and Medusaceratops^[54]
Lophorhothon	1960	Mooreville Chalk, Tar Heel/Coachman Formation? (Late Cretaceous, Campanian)	United States ( Alabama North Carolina?)	Although incomplete, the holotype skull preserves evidence of a crest
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^[55]
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^[56]
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 Piatnitzkysaurus and Condorraptor^[57]
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
Mexidracon	2025	Cerro del Pueblo Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	Had unusually long hands for an ornithomimosaur
Microvenator	1970	Cloverly Formation (Early Cretaceous, Albian)	United States ( Montana)	Teeth from Deinonychus have been mistakenly attributed to this genus
Mierasaurus	2017	Cedar Mountain Formation (Early Cretaceous, Valanginian)	United States ( Utah)	One of the latest-surviving turiasaurs^[58]
Moabosaurus	2017	Cedar Mountain Formation (Early Cretaceous, Aptian)	United States ( Utah)	Described as a macronarian^[59] but has since been reinterpreted as a turiasaur closely related to Mierasaurus^[58]
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 misplaced cheek horn^[60]
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, Kimmeridgian 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^[61]
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^[62]
Nedcolbertia	1998	Cedar Mountain Formation (Early Cretaceous, Valanginian)	United States ( Utah)	Known from three partial skeletons. The specific name, 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^[63]
Nodocephalosaurus	1999	Kirtland Formation (Late Cretaceous, Campanian)	United States ( New Mexico)	Closely related to Asian ankylosaurids^[64]
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^[65] along the Turonian shoreline^[66]
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^[67]
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^[68]
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^[69]
Orodromeus	1988	Two Medicine Formation (Late Cretaceous, Campanian)	United States ( Montana)	Eggs considered to belong to this taxon may have actually come from a troodontid^[70]
Oryctodromeus	2007	Blackleaf Formation, Wayan Formation (Late Cretaceous, Cenomanian)	United States ( Idaho Montana)	Several specimens have been preserved in burrows
Osmakasaurus	2011	Lakota Formation (Early Cretaceous, Valanginian)	United States ( South Dakota)	Originally named as a species of Camptosaurus
Pachycephalosaurus	1943	Hell Creek Formation, Lance Formation, Scollard Formation? (Late Cretaceous, Maastrichtian)	Canada ( Alberta?) United States ( Montana South Dakota Wyoming)	Possessed a tall, rounded head dome surrounded by bony knobs
Pachyrhinosaurus	1950	Horseshoe Canyon Formation, Prince Creek Formation, St. Mary River Formation, Wapiti Formation (Late Cretaceous, Campanian to Maastrichtian)	Canada ( Alberta) United States ( Alaska)	Three species have been named, each with a unique pattern of cranial ornamentation
Palaeoscincus	1856	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Although many restorations depict it with the spikes of Edmontonia and the tail club of Ankylosaurus, this is most likely incorrect
Panoplosaurus	1919	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Unlike other nodosaurids, it lacked enlarged spikes
Parasaurolophus	1922	Dinosaur Park Formation, Fruitland Formation, Kaiparowits Formation, Kirtland Formation (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( New Mexico Utah)	Possessed a curved, hollow crest that varied in size between species
Paraxenisaurus	2020	Cerro del Pueblo Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	Described as the first deinocheirid from North America
Parksosaurus	1937	Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta)	Had long toes which may be an adaptation to walking on soft soils in watercourses and marshlands^[65]
Paronychodon	1876	Hell Creek Formation, Judith River Formation, Lance Formation (Late Cretaceous, Campanian to Maastrichtian)	United States ( Montana North Dakota South Dakota Wyoming)	Only known from highly distinctive teeth
Pawpawsaurus	1996	Paw Paw Formation (Early Cretaceous, Albian)	United States ( Texas)	Had enlarged nasal cavities that gave it an acute sense of smell, even more powerful than that of contemporary theropods^[71]
Pectinodon	1982	Hell Creek Formation, Lance Formation (Late Cretaceous, Maastrichtian)	United States ( Wyoming)	Had comb-like serrations on its teeth
Peloroplites	2008	Cedar Mountain Formation (Late Cretaceous, Cenomanian to Turonian)	United States ( Utah)	One of the largest known nodosaurids
Pentaceratops	1923	Fruitland Formation, Kirtland Formation (Late Cretaceous, Campanian)	United States ( New Mexico)	Its epijugal bones, the hornlets under its eyes, were relatively large
Planicoxa	2001	Cedar Mountain Formation (Early Cretaceous, Barremian to Albian)	United States ( Utah)	The rear of its ilium was characteristically flat
Platypelta	2018	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Originally assigned to Euoplocephalus but was given its own genus because of several morphological differences
Platytholus	2023	Hell Creek Formation (Late Cretaceous, Maastrichtian)	United States ( Montana)	Differs from juveniles of the contemporary Pachycephalosaurus and Sphaerotholus, hence its classification as a new genus
Podokesaurus	1911	Portland Formation (Early Jurassic, Hettangian to Sinemurian)	United States ( Massachusetts)	May have had a tail one and a half times longer than the rest of its skeleton^[72]
Polyodontosaurus	1932	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	May be identical to Latenivenatrix^[73]
Polyonax	1874	Denver Formation (Late Cretaceous, Maastrichtian)	United States ( Colorado)	Poorly known
Prenoceratops	2004	Oldman Formation, Two Medicine Formation (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( Montana)	The only basal neoceratopsian known from a bonebed
Priconodon	1888	Arundel Formation (Early Cretaceous, Aptian to Albian)	United States ( Maryland)	Large but only known from teeth
Probrachylophosaurus	2015	Foremost Formation, Judith River Formation (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( Montana)	Shows a skull morphology transitional between crestless and crested brachylophosaurins
Propanoplosaurus	2011	Patuxent Formation (Early Cretaceous, Aptian)	United States ( Maryland)	Only known from the imprints of a neonate skeleton
Prosaurolophus	1916	Dinosaur Park Formation, Two Medicine Formation (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( Montana)	Had a relatively large head for a hadrosaur
Protohadros	1998	Woodbine Formation (Late Cretaceous, Cenomanian)	United States ( Texas)	Possessed a downturned jaw which may be an adaptation to grazing on low-growing plants
Pteropelyx	1889	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Potentially synonymous with Corythosaurus, although this cannot be confirmed due to the lack of cranial remains^[74]
Rativates	2016	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Originally described as a specimen of Struthiomimus
Regaliceratops	2015	St. Mary River Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta)	Possessed a series of large, pentagonal plates lining its frill
Richardoestesia	1990	Aguja Formation, Dinosaur Park Formation, Ferris Formation?, Hell Creek Formation?, Horseshoe Canyon Formation?, Lance Formation?, Scollard Formation? (Late Cretaceous, Campanian to Maastrichtian?)	Canada ( Alberta) United States ( Montana? Texas Wyoming?)	Teeth assigned to this genus have been recovered all around the world, in deposits spanning from the Jurassic to the Cretaceous, although they may not represent a single taxon
Rugocaudia	2012	Cloverly Formation (Early Cretaceous, Aptian to Albian)	United States ( Montana)	Some of this genus' remains include several caudal vertebrae
Sarahsaurus	2011	Kayenta Formation (Early Jurassic, Sinemurian to Pliensbachian)	United States ( Arizona)	Possessed strong hands which may indicate a feeding specialization
Saurolophus	1912	Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta)	Had a short, solid crest that pointed directly upwards. A larger, more well-known species has been found in Mongolia
Sauropelta	1970	Cedar Mountain Formation?, Cloverly Formation (Early Cretaceous, Albian)	United States ( Montana Utah? Wyoming)	Its tail had at least forty vertebrae, making up half of its total body length
Saurophaganax	1995	Morrison Formation (Late Jurassic, Kimmeridgian)	United States ( New Mexico? Oklahoma)	Originally described as a large theropod, but was later suggested to be a chimera of sauropod and theropod bones. The holotype bone may have belonged to a sauropod^[75]
Sauroposeidon	2000	Antlers Formation, Cloverly Formation, Glen Rose Formation, Twin Mountains Formation (Early Cretaceous, Aptian to Albian)	United States ( Oklahoma Texas Wyoming)	Could raise its head up to 18 metres (59 ft) in the air, the height of a six-story building^[76]
Saurornitholestes	1978	Dinosaur Park Formation, Donoho Creek Formation, Kirtland Formation, Mooreville Chalk, Oldman Formation, Tar Heel/Coachman Formation, Two Medicine Formation (Late Cretaceous, Campanian to Maastrichtian)	Canada ( Alberta) United States ( Alabama Montana New Mexico South Carolina)	Its second premaxillary teeth could be adapted to preening feathers^[77]
Scolosaurus	1928	Dinosaur Park Formation, Oldman Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Once widely believed to be synonymous with other Campanian ankylosaurids
Scutellosaurus	1981	Kayenta Formation (Early Jurassic, Sinemurian)	United States ( Arizona)	Had hundreds of osteoderms arranged in rows along its back and tail
Segisaurus	1936	Navajo Sandstone (Early Jurassic, Pliensbachian to Toarcian)	United States ( Arizona)	Preserves evidence of a wishbone similar to that of modern birds
Seitaad	2010	Navajo Sandstone (Early Jurassic, Pliensbachian)	United States ( Utah)	The holotype may have died when a sand dune collapsed on it^[78]
Siats	2013	Cedar Mountain Formation (Late Cretaceous, Cenomanian)	United States ( Utah)	Large but inconsistent in phylogenetic placement
Sierraceratops	2022	Hall Lake Formation (Late Cretaceous, Campanian to Maastrichtian)	United States ( New Mexico)	May be part of a unique clade of chasmosaurine ceratopsids only known from southern Laramidia^[79]
Silvisaurus	1960	Dakota Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian)	United States ( Kansas)	Hypothesized to live in a forested habitat
Smitanosaurus	2020	Morrison Formation (Late Jurassic, Oxfordian to Tithonian)	United States ( Colorado)	Only known from a partial skull and some vertebrae
Sonorasaurus	1998	Turney Ranch Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian)	United States ( Arizona)	State dinosaur of Arizona
Sphaerotholus	2002	Dinosaur Park Formation, Frenchman Formation, Hell Creek Formation, Horseshoe Canyon Formation, Kirtland Formation (Late Cretaceous, Campanian to Maastrichtian)	Canada ( Alberta Saskatchewan) United States ( Montana New Mexico)	Five species have been named, all known from skull elements. Lived in a broad range
Spiclypeus	2016	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Has been described as "boldly audacious"^[80]
Spinops	2011	Dinosaur Park Formation?/Oldman Formation? (Late Cretaceous, Campanian)	Canada ( Alberta)	Described almost a century after its remains were collected
Stegoceras	1902	Dinosaur Park Formation, Fruitland Formation?, Kirtland Formation?, Oldman Formation (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( New Mexico?)	May have been an indiscriminate bulk-feeder due to the shape of its snout^[81]
Stegopelta	1905	Frontier Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian)	United States ( Wyoming)	May have possessed a sacral shield similar to other nodosaurids
Stegosaurus	1877	Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)	United States ( Colorado Wyoming)	Had a single alternating row of large, kite-shaped plates
Stellasaurus	2020	Two Medicine Formation (Late Cretaceous, Campanian)	United States ( Montana)	Possessed an enlarged, thickened nasal horn
Stenonychosaurus	1932	Dinosaur Park Formation, Two Medicine Formation? (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( Montana?)	Its brain-to-body mass ratio is one of the highest of any non-avian dinosaur
Stephanosaurus	1914	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Poorly known
Stokesosaurus	1974	Morrison Formation (Late Jurassic, Kimmeridgian? to Tithonian)	United States ( South Dakota? Utah)	Only known from a few remains but they are enough to tell that it was a tyrannosauroid
Struthiomimus	1917	Horseshoe Canyon Formation?, Lance Formation?, Oldman Formation (Late Cretaceous, Campanian to Maastrichtian?)	Canada ( Alberta) United States ( Wyoming?)	Known from many specimens, indicating it was a common animal
Styracosaurus	1913	Dinosaur Park Formation, Two Medicine Formation? (Late Cretaceous, Campanian)	Canada ( Alberta) United States ( Montana?)	Possessed several long horns jutting out from the top of its frill, the patterns of which could have varied between individuals^[82]
Supersaurus	1985	Morrison Formation (Late Jurassic, Tithonian)	United States ( Colorado Wyoming)	Several remains were originally believed to represent their own genera
Suskityrannus	2019	Moreno Hill Formation (Late Cretaceous, Turonian)	United States ( New Mexico)	Small yet already possessed several features of larger, more derived tyrannosaurids, including an arctometatarsus
Suuwassea	2004	Morrison Formation (Late Jurassic, Oxfordian to Tithonian)	United States ( Montana)	Shares features with both diplodocids and dicraeosaurids, but is most likely a member of the latter group^[14]^[49]
Talos	2011	Kaiparowits Formation (Late Cretaceous, Campanian)	United States ( Utah)	The holotype specimen preserves a pathology on its sickle claw^[83]
Tanycolagreus	2005	Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)	United States ( Colorado Utah Wyoming)	Had a long, blunt snout
Tatankacephalus	2009	Cloverly Formation (Early Cretaceous, Aptian to Albian)	United States ( Montana)	Retained premaxillary teeth in its upper jaws, a basal trait
Tawa	2009	Chinle Formation (Late Triassic, Norian)	United States ( New Mexico)	Well-preserved but inconsistent in phylogenetic placement
Tenontosaurus	1970	Antlers Formation, Arundel Formation, Cedar Mountain Formation, Cloverly Formation, Paluxy Formation, Twin Mountains Formation, Wayan Formation (Early Cretaceous, Aptian to Albian)	United States ( Idaho Maryland Montana Oklahoma Texas Utah)	Remains of this genus are often found associated with skeletons of Deinonychus^[84]
Teratophoneus	2011	Kaiparowits Formation (Late Cretaceous, Campanian)	United States ( Utah)	Its snout was shorter and deeper than those of other tyrannosaurids
Terminocavus	2020	Kirtland Formation (Late Cretaceous, Campanian)	United States ( New Mexico)	Had a teardrop-shaped hole on the top of its frill which was almost closed off by a pair of epoccipitals
Texacephale	2010	Aguja Formation (Late Cretaceous, Campanian)	United States ( Texas)	Might represent a specimen of Stegoceras^[85]
Texasetes	1995	Paw Paw Formation (Early Cretaceous, Albian)	United States ( Texas)	Potentially synonymous with Pawpawsaurus
Thanatotheristes	2020	Foremost Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	A close relative of Daspletosaurus^[86]
Theiophytalia	2006	Purgatoire Formation (Early Cretaceous, Aptian to Albian)	United States ( Colorado)	Only known from a skull originally referred to Camptosaurus
Thescelosaurus	1913	Frenchman Formation, Hell Creek Formation, Lance Formation, Laramie Formation, Scollard Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta Saskatchewan) United States ( Colorado Montana North Dakota South Dakota Wyoming)	One specimen was originally considered to have preserved its heart, although this was later found to be a mineral concretion^[87]
Thespesius	1856	Lance Formation (Late Cretaceous, Maastrichtian)	United States ( South Dakota)	Once suggested to be a possible Miocene mammal
Tichosteus	1877	Morrison Formation (Late Jurassic, Kimmeridgian)	United States ( Colorado)	Two species have been named, both from isolated vertebrae
Titanoceratops	2011	Fruitland Formation?/Kirtland Formation? (Late Cretaceous, Campanian)	United States ( New Mexico)	Potentially a large, old specimen of Pentaceratops^[62]
Tlatolophus	2021	Cerro del Pueblo Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	Possessed a short, broad crest resembling an inverted comma
Torosaurus	1891	Frenchman Formation, Hell Creek Formation, Lance Formation, Scollard Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta Saskatchewan) United States ( Colorado? Montana? New Mexico? North Dakota? South Dakota Texas? Utah? Wyoming)	Once believed to be potentially synonymous with Triceratops
Torvosaurus	1979	Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)	United States ( Colorado Wyoming)	Had short but powerfully built arms. Several species, many of them unnamed, have been found in Europe, South America and possibly Africa
Tototlmimus	2016	Packard Formation (Late Cretaceous, Campanian)	Mexico ( Sonora)	The southernmost ornithomimid known from North America
Trachodon	1856	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Several remains assigned to this genus actually belong to other taxa, most notably Edmontosaurus
Triceratops	1889	Denver Formation, Evanston Formation, Hell Creek Formation, Lance Formation, Laramie Formation, Scollard Formation (Late Cretaceous, Maastrichtian)	Canada ( Alberta Saskatchewan?) United States ( Colorado Montana South Dakota Wyoming)	A common ceratopsid with long brow horns and a short nasal horn
Trierarchuncus	2020	Hell Creek Formation (Late Cretaceous, Maastrichtian)	United States ( Montana)	Known from remains of different sizes which depict how the claws of alvarezsaurids grew more hooked as they aged
Troodon	1856	Judith River Formation, Two Medicine Formation? (Late Cretaceous, Campanian)	United States ( Montana)	Only known from teeth. Most referred skeletal remains cannot be confidently assigned to this genus^[73]
Tyrannosaurus	1905	Frenchman Formation, Hall Lake Formation, Hell Creek Formation, Lance Formation, Willow Creek Formation (Late Cretaceous, Campanian to Maastrichtian)	Canada ( Alberta Saskatchewan) United States ( Colorado Montana New Mexico South Dakota Wyoming)	The last, largest and most well-known tyrannosaurid
Unescoceratops	2012	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Had the roundest teeth of any known leptoceratopsid
Utahceratops	2010	Kaiparowits Formation (Late Cretaceous, Campanian)	United States ( Utah)	Almost the entire skeleton is known, including the skull
Utahraptor	1993	Cedar Mountain Formation (Early Cretaceous, Berriasian to Valanginian)	United States ( Utah)	Very large and powerfully built
Uteodon	2011	Morrison Formation (Late Jurassic, Tithonian)	United States ( Utah)	May be a species of Camptosaurus, with a referred braincase being from Dryosaurus^[88]
Vagaceratops	2010	Dinosaur Park Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Possessed a row of fused epoccipitals folding over the top of the frill
Velafrons	2007	Cerro del Pueblo Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	May have had elongated neural spines similar to those of Hypacrosaurus altispinus
Venenosaurus	2001	Cedar Mountain Formation (Early Cretaceous, Aptian to Albian)	United States ( Utah)	Its skeleton has traits of both titanosaurs and more basal macronarians
Wendiceratops	2015	Oldman Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Had three pairs of enlarged, curved epiparietals at the very top of its frill
Xenoceratops	2012	Foremost Formation (Late Cretaceous, Campanian)	Canada ( Alberta)	Possessed two long spikes at the top of its frill with smaller knobs at their bases
Yehuecauhceratops	2017	Aguja Formation (Late Cretaceous, Campanian)	Mexico ( Coahuila)	One of the smallest known ceratopsids
Yurgovuchia	2012	Cedar Mountain Formation (Early Cretaceous, Valanginian)	United States ( Utah)	May have had a flexible tail due to the structure of its caudal vertebrae
Zapsalis	1876	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Some teeth referred to this genus actually belong to Saurornitholestes^[77]
Zephyrosaurus	1980	Cloverly Formation (Early Cretaceous, Aptian to Albian)	United States ( Montana)	Currently only known from fragmentary remains but several undescribed specimens exist^[89]
Ziapelta	2014	Kirtland Formation (Late Cretaceous, Campanian)	United States ( New Mexico)	Many specimens are known, most from the front part of the animal
Zuniceratops	1998	Moreno Hill Formation (Late Cretaceous, Turonian to Coniacian)	United States ( New Mexico)	Carried a pair of brow horns despite not being a member of the Ceratopsidae
Zuul	2017	Judith River Formation (Late Cretaceous, Campanian)	United States ( Montana)	Preserves several osteoderms, keratin and skin remains

Invalid and potentially valid genera

Agathaumas sylvestris: Mostly well-known from a painting by Charles R. Knight. It may have been a synonym of Triceratops, but without cranial remains, this cannot be confirmed.
Alcovasaurus longispinus: Although originally named as a species of Stegosaurus, it may actually be a species of the otherwise European Miragaia. However, a later study has considered Miragaia a junior synonym of Dacentrurus, making Alcovasaurus a potentially distinct genus.
Antrodemus valens: May represent the same animal as Allosaurus. If so, the name Antrodemus would have priority. However, because it is based on undiagnostic remains of uncertain provenance, this cannot be confirmed.
Apatodon mirus: Its holotype was originally believed to be the jawbone of a Mesozoic pig, but has been reinterpreted as a dinosaur vertebra. What type of dinosaur it belonged to is unknown, but there have been suggestions that it was from Allosaurus.
"Beelemodon": Known only from two teeth found in Wyoming. They share features of compsognathids, dromaeosaurids and basal oviraptorosaurs.
"Capitalsaurus": The official dinosaur of the District of Columbia. It is known from a single vertebra discovered at the intersection of First and F Streets S.E., which is now appropriately named "Capitalsaurus Court".
Cathetosaurus lewisi: Usually seen as a species of Camarasaurus, but an unpublished study argues that it might be a distinct genus.
Claorhynchus trihedrus: An indeterminate cerapod that may be either a hadrosaurid or a ceratopsid, in which case it may be a synonym of Triceratops.
"Coelosaurus" antiquus: The generic name is said to be preoccupied, but its namesake remains obscure.
"Comanchesaurus kuesi": Only named in a dissertation. It has been described as a possible indeterminate saurischian.
Deinodon horridus: Only known from teeth. Several referred teeth have since been found to belong to already known species, and the holotype itself could belong to Gorgosaurus.
Dracorex hogwartsia: Described as a small, flat-headed pachycephalosaur. However, it is likely that it is just a juvenile Pachycephalosaurus.
Drinker nisti: May be a synonym of Nanosaurus.
Epanterias amplexus: Possibly a large specimen of Allosaurus, but it may be a different taxon due to its younger age.
Latenivenatrix mcmasterae: The largest known troodontid. It is sometimes suggested to be synonymous with Stenonychosaurus, which its remains were originally assigned to.
"Magulodon muirkirkensis": Only known from a single tooth that may belong to either an ornithopod or a basal ceratopsian.
"Microcephale": Said to be an extremely small pachycephalosaur, with skull caps only 5 centimetres (2.0 in) long.
Mojoceratops perifania: May be a synonym of Chasmosaurus.
Nanotyrannus lancensis: Most likely a juvenile Tyrannosaurus, although a more recent study suggests it might be a possibly distinct taxon based on referred specimens.
Nedoceratops hatcheri: Due to its lack of a nasal horn, it has been named "Diceratops" (which is preoccupied by an insect) and Diceratus. However, it may simply be an unusual specimen of Triceratops.
Ojoceratops fowleri: May be ancestral to Triceratops or a synonym of Eotriceratops.
"Orcomimus": Potentially attributable to any of the ornithomimosaur taxa known from the Hell Creek Formation.
Othnielia rex: Only known from an undiagnostic femur, but it may have belonged to Nanosaurus anyway.
Othnielosaurus consors: Most likely a synonym of Nanosaurus.
Palaeopteryx thomsoni: Known from a few very small bones which could belong to either a bird or a small bird-like dinosaur.
Protoavis texensis: Described as a Triassic bird but is most likely a chimera consisting of elements from various unrelated tetrapods.
Rhinorex condrupus: Phylogenetic analysis shows that it may fall within Gryposaurus, and thus be a junior synonym of that genus.
Rubeosaurus ovatus: Likely a species of Styracosaurus, or even simply an unusual specimen of S. albertensis.
Stygimoloch spinifer: Had a short skull dome with long horns jutting out from behind it. It is usually thought to be a subadult Pachycephalosaurus, but has been noted to be stratigraphically younger.
Tatankaceratops sacrisonorum: Noted to possess a strange mix of features of both juvenile and adult Triceratops. It may be a dwarf specimen of that genus or an individual that stopped growing prematurely.