# 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

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. However, the most reliable early record of North American dinosaurs comes from fragmentary saurischian fossils unearthed from the Upper Triassic Dockum Group of Texas. 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.
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. 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.

## 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

| 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 |
| 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 |
| 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 |
| Albertosaurus | 1905 | Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian) | Canada ( Alberta) | Known from more than thirty specimens, twenty-six of which are preserved together |
| 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" |
| 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 |
| 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 |
| 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 |
| 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, but a referred species may represent a separate taxon |
| 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 |
| 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 |
| Caenagnathus | 1940 | Dinosaur Park Formation (Late Cretaceous, Campanian) | Canada ( Alberta) | One of the largest known caenagnathids |
| 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 |
| 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 |
| 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" |
| 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 |
| 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 |
| 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 before receiving its own genus name |
| 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 |
| 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 |
| 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 but this hypothesis has been criticized |
| 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 |
| 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 |
| 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 but it is possible that it could not handle the stress of supersonic travel |
| 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 |
| 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 |
| Dyoplosaurus | 1924 | Dinosaur Park Formation (Late Cretaceous, Campanian) | Canada ( Alberta) | The holotype specimen preserves skin impressions |
| 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 |
| 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 |
| 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 |
| Fona | 2024 | Cedar Mountain Formation (Late Cretaceous, Cenomanian) | United States ( Utah) | Possibly a semi-fossorial animal based on the related Oryctodromeus |
| 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 |
| Fruitadens | 2010 | Morrison Formation (Late Jurassic, Tithonian) | United States ( Colorado) | One of the smallest known ornithischians |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Iani | 2023 | Cedar Mountain Formation (Late Cretaceous, Cenomanian) | United States ( Utah) | Represents the family Tenontosauridae, a clade of North American rhabdodontomorphs |
| 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 |
| 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 |
| 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. The exact holotypic bones belonged to a lambeosaurine |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Moabosaurus | 2017 | Cedar Mountain Formation (Early Cretaceous, Aptian) | United States ( Utah) | Described as a macronarian but has since been reinterpreted as a turiasaur closely related to Mierasaurus |
| 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 |
| 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 |
| 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 |
| 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 |
| Nodocephalosaurus | 1999 | Kirtland Formation (Late Cretaceous, Campanian) | United States ( New Mexico) | Closely related to Asian ankylosaurids |
| 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 along the Turonian shoreline |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Polyodontosaurus | 1932 | Dinosaur Park Formation (Late Cretaceous, Campanian) | Canada ( Alberta) | May be identical to Latenivenatrix |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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" |
| 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 |
| 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 |
| 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 |
| Talos | 2011 | Kaiparowits Formation (Late Cretaceous, Campanian) | United States ( Utah) | The holotype specimen preserves a pathology on its sickle claw |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Zephyrosaurus | 1980 | Cloverly Formation (Early Cretaceous, Aptian to Albian) | United States ( Montana) | Currently only known from fragmentary remains but several undescribed specimens exist |
| 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
* Alcovasaurus
* Antrodemus
* "Capitalsaurus"
* Cathetosaurus
* "Coelosaurus"
* Deinodon
* Dracorex
* Drinker
* Epanterias
* Latenivenatrix
* Mojoceratops
* Nanotyrannus
* Nedoceratops
* Ojoceratops
* Othnielia
* Othnielosaurus
* Rhinorex
* Rubeosaurus
* Stygimoloch
* Tatankaceratops
* 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.

## Timeline

This is a timeline of selected dinosaurs from the list above. Time is measured in Ma, megaannum, along the x-axis.