List of Mesozoic bird-line archosaur genera (A–B)
From Wikipedia, the free encyclopedia
This list of Mesozoic bird-line archosaur genera is a comprehensive listing of all Mesozoic genera that are included in the clade Avemetatarsalia (alternatively known as Pan-Aves), including dinosaurs, pterosaurs, silesaurids, lagerpetids, and more basal genera. The list includes all commonly accepted genera whose names begin with the letters A and B. The list currently includes 302 genera.
Scope and terminology
There is no official, canonical list of Mesozoic bird-line archosaur genera, but thorough attempts have been made for its various subgroups, such as George Olshevsky's Dinosaur Genera List,[1] the book The Dinosauria,[2] Mikko Haaramo's Phylogeny Archive,[3] Mike Hanson's The Pterosauria,[4] the Pterosaur Species List,[5] Donald F. Glut's Dinosaurs: The Encyclopedia series,[6] Holtz's list of Mesozoic dinosaurs,[7] Molina-Perez & Larramendi's list of theropods,[8] and Mickey Mortimer's Theropod Database.[9] These lists have been supplemented with more recent publications to create this one.
- Genus: The generic name of the taxon, sourced to its description publication.
- Authors: Full names of the authors of the descriptions. This column can be sorted by last names.
- Year: The year when the descriptions were physically published. These are not necessarily the years the names became valid according to the rules of the International Commission on Zoological Nomenclature (ICZN).
- Formation: The geological formations each taxon was found in, along with their epoch and age. In the case of multiple formations, holotype localities are marked by an asterisk.
- Location: Every country and first-level subdivision the taxon was found in. In the case of multiple locations, holotype localities are marked by an asterisk.
The list
| Genus | Authors | Year | Formation | Location | Notes | Images |
|---|---|---|---|---|---|---|
| Aardonyx[10] | - Adam M. Yates - Matthew F. Bonnan - Johann Neveling - Anusuya Chinsamy - Marc G. Blackbeard |
2010 | Upper Elliot Formation (Early Jurassic, Sinemurian to Pliensbachian) |
 South Africa(  Free State) |
Primarily bipedal but also capable of limited quadrupedal locomotion |  |
| Abavornis[11] | - Andrey V. Panteleyev | 1998 | Bissekty Formation (Late Cretaceous, Turonian) |
 Uzbekistan(Navoiy) |
Only known from fragmentary coracoids | |
| Abdarainurus[12] | - Alexander O. Averianov - Alexey V. Lopatin |
2020 | Alagteeg Formation (Late Cretaceous, Santonian to Campanian) |
 Mongolia(  Ömnögovi) |
May represent an unknown lineage of Asian macronarians |  |
| Abditosaurus[13] | - Bernat Vila - Albert G. Sellés - Miguel Moreno-Azanza - Novella L. Razzolini - Alejandro Gil-Delgado - José I. Canudo - Àngel Galobart |
2022 | Conques Formation (Late Cretaceous, Maastrichtian) |
 Spain(  Catalonia) |
Larger and distantly related to other European sauropods, suggesting it was an immigrant from another continent |  |
| Abelisaurus[14] | - José F. Bonaparte - Fernando E. Novas |
1985 | Anacleto Formation (Late Cretaceous, Campanian) |
 Argentina(  Río Negro) |
Only known from a single partial skull |  |
| Abitusavis[15] | - Min Wang - Zhiheng Li - Qingguo Liu - Zhonghe Zhou |
2020 | Yixian Formation (Early Cretaceous, Barremian) |
 China(Liaoning) |
Preserved alongside fish remains, suggesting it was piscivorous | |
| Abrictosaurus[16] | - James A. Hopson | 1975 | Upper Elliot Formation (Early Jurassic, Sinemurian to Pliensbachian) |
 Lesotho(Qacha's Nek*) South Africa(  Eastern Cape) |
Known from two skulls, one of which possesses tusks, which may be an indication of sexual dimorphism |  |
| Abrosaurus[17] | - Hui Ouyang | 1989 | Xiashaximiao Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
China (Sichuan) |
Had a delicate skull with very large fenestrae |  |
| Abydosaurus[18] | - Daniel J. Chure - Brooks B. Britt - John A. Whitlock - Jeffrey A. Wilson |
2010 | Cedar Mountain Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
 United States(  Utah) |
Had a domed skull similar to that of Giraffatitan |  |
| Acantholipan[19] | - Héctor E. Rivera-Sylva - Eberhard Frey - Wolfgang Stinnesbeck - Gerardo Carbot-Chanona - Iván E. Sanchez-Uribe - José R. Guzmán-Gutiérrez |
2018 | Pen Formation (Late Cretaceous, Santonian) |
 Mexico(  Coahuila) |
Had spike-like osteoderms interpreted as coming from over the hips |  |
| Acanthopholis[20] | - Thomas H. Huxley | 1867 | Chalk Group (Late Cretaceous, Cenomanian) |
 England(  Kent) |
Possessed keeled oval scutes as well as long spines |  |
| Achelousaurus[21] | - Scott D. Sampson | 1995 | 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[22] | - David C. Evans - Derek W. Larson - Philip J. Currie |
2013 | Hell Creek Formation (Late Cretaceous, Maastrichtian) |
United States ( Montana) |
One of the geologically youngest dromaeosaurids |  |
| Achillesaurus[23] | - Agustín G. Martinelli - Ezequiel I. Vera |
2007 | Bajo de la Carpa Formation (Late Cretaceous, Santonian) |
Argentina ( Río Negro) |
Potentially a junior synonym of the contemporary Alvarezsaurus |  |
| Achillobator[24] | - Altangerel Perle - Mark A. Norell - James M. Clark |
1999 | Bayanshiree Formation (Late Cretaceous, Cenomanian to Coniacian) |
Mongolia (  Dornogovi) |
More robustly built compared to other dromaeosaurids |  |
| Acristavus[25] | - Terry A. Gates - John R. Horner - Rebecca R. Hanna - C. Riley Nelson |
2011 | Two Medicine Formation (Late Cretaceous, Campanian)* Wahweap Formation (Late Cretaceous, Campanian) |
United States ( Montana* Utah) |
Has no skull ornamentation |  |
| Acrocanthosaurus[26] | - J. Willis Stovall - Wann Langston |
1950 | Antlers Formation (Early Cretaceous, Aptian)* Arundel Formation (Early Cretaceous, Aptian to Albian) Cloverly Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) Twin Mountains Formation (Early Cretaceous, Aptian) |
United States (  Maryland Oklahoma* Texas Wyoming) |
Possessed elongated neural spines that would have supported a low sail or hump in life |  |
| Acrotholus[27] | - David C. Evans - Ryan K. Schott - Derek W. Larson - Caleb M. Brown - Michael J. Ryan |
2013 | Milk River Formation (Late Cretaceous, Santonian) |
 Canada(  Alberta) |
Had a tall, oval-shaped dome |  |
| Adamantisaurus[28] | - Rodrigo M. Santucci - Reinaldo J. Bertini |
2006 | Adamantina Formation (Late Cretaceous, Coniacian to Maastrichtian) |
 Brazil(  São Paulo) |
Derived for a titanosaur as indicated by the ball-and-socket articulations of its caudal vertebrae |  |
| Adasaurus[29] | - Rinchen Barsbold | 1983 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Its sickle claw was markedly reduced compared to other dromaeosaurids |  |
| Adelolophus[30] | - Terry A. Gates - Zubair Jinnah - Carolyn Levitt - Michael A. Getty |
2014 | Wahweap Formation (Late Cretaceous, Campanian) |
United States ( Utah) |
Potentially a close relative of Parasaurolophus and Tlatolophus |  |
| Adeopapposaurus[31] | - Ricardo N. Martínez | 2009 | Cañón del Colorado Formation (Early Jurassic, Hettangian to Toarcian) |
Argentina (  San Juan) |
May have had a keratinous beak |  |
| Adratiklit[32] | - Susannah C.R. Maidment - Thomas J. Raven - Driss Ouarhache - Paul M. Barrett |
2020 | El Mers III Formation (Middle Jurassic, Bathonian to Callovian) |
 Morocco(Fez-Meknes) |
More closely related to European stegosaurs like Dacentrurus than African ones |  |
| Adynomosaurus[33] | - Albert Prieto-Márquez - Víctor Fondevilla - Albert G. Sellés - Jonathan R. Wagner - Àngel Galobart |
2019 | Conques Formation (Late Cretaceous, Maastrichtian) |
Spain ( Catalonia) |
Relatively basal for a hadrosaurid despite its late age |  |
| Aegyptosaurus[34] | - Ernst Stromer | 1932 | Bahariya Formation (Late Cretaceous, Cenomanian) |
 Egypt(  Giza) |
Its holotype was destroyed in World War II |  |
| Aeolosaurus[35] | - Jaime E. Powell | 1987 | Angostura Colorada Formation (Late Cretaceous, Campanian to Maastrichtian)* Lago Colhué Huapí Formation (Late Cretaceous, Campanian to Maastrichtian) Los Alamitos Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina (  Chubut Río Negro*) |
Known from the remains of several individuals |  |
| Aepisaurus[36] | - Paul Gervais | 1852 | Grès verts hevétiques (Early Cretaceous, Albian) |
 France(  Provence-Alpes-Côte d'Azur) |
Shares some features with camarasaurids and titanosaurs, but its classification is uncertain |  |
| Aepyornithomimus[37] | - Tsogtbaatar Chinzorig - Yoshitsugu Kobayashi - Khishigjav Tsogtbaatar - Philip J. Currie - Mahito Watabe - Rinchen Barsbold |
2017 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
The first ornithomimosaur named from a dry desert environment |  |
| Aerodactylus[38] | - Steven U. Vidovic - David M. Martill |
2014 | Altmühltal Formation (Late Jurassic, Tithonian) |
 Germany(  Bavaria) |
Possibly synonymous with Pterodactylus |  |
| Aerodraco[39] | - Borja Holgado - Rodrigo V. Pêgas |
2020 | Cambridge Greensand (Early Cretaceous, Albian) |
England (  Cambridgeshire) |
Assigned to four different pterosaur genera before its eventual reassessment as its own genus |  |
| Aerosteon[40] | - Paul C. Sereno - Ricardo N. Martínez - Jeffrey A. Wilson - David J. Varricchio - Oscar A. Alcober - Hans C. E. Larsson |
2008 | Anacleto Formation (Late Cretaceous, Campanian) |
Argentina (  Mendoza) |
Its bones were extensively pneumatized, suggesting an air sac system like that of modern birds |  |
| Aerotitan[41] | - Fernando E. Novas - Martin Kundrát - Federico L. Agnolín - Martín D. Ezcurra - Per E. Ahlberg - Marcelo P. Isasi - Alberto Arriagada - Pablo Chafrat |
2012 | Allen Formation (Late Cretaceous, Maastrichtian) |
Argentina ( Río Negro) |
The first unambiguous azhdarchid from South America |  |
| Aetodactylus[42] | - Timothy S. Myers | 2010 | Tarrant Formation (Late Cretaceous, Cenomanian) |
United States ( Texas) |
Had no bony crests on the lower jaw |  |
| Afromimus[43] | - Paul C. Sereno | 2017 | Elrhaz Formation (Early Cretaceous, Barremian to Albian) |
 Niger(Agadez) |
Originally described as an ornithomimosaur but has since been redescribed as a possible noasaurid |  |
| Afrotapejara[44] | - David M. Martill - Roy Smith - David M. Unwin - Alexander Kao - James McPhee - Nizar Ibrahim |
2020 | Ifezouane Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
Morocco (Drâa-Tafilalet) |
The first tapejarid discovered in Africa |  |
| Afrovenator[45] | - Paul C. Sereno - Jeffrey A. Wilson - Hans C. E. Larsson - Didier B. Dutheil - Hans-Dieter Sues |
1994 | Tiourarén Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
Niger (Agadez) |
Originally thought to hail from the Early Cretaceous |  |
| Agathaumas[46] | - Edward D. Cope | 1872 | Lance Formation (Late Cretaceous, Maastrichtian) |
United States ( Wyoming) |
A painting by Charles Knight produced under this creature's name is actually based on fragments of other animals |  |
| Agilisaurus[47] | - Guangzhao Peng | 1990 | Xiashaximiao Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
China (Sichuan) |
The holotype was discovered during the construction of the Zigong Dinosaur Museum, where it is now housed |  |
| Agnosphitys[48] | - Nicholas C. Fraser - Kevin Padian - Gordon M. Walkden - A. L. M. Davis |
2002 | Magnesian Conglomerate (Late Triassic, Norian to Rhaetian) |
England (Bristol) |
Has been considered a theropod, a sauropodomorph, and a silesaurid |  |
| Agrosaurus[49] | - Harry G. Seeley | 1891 | Magnesian Conglomerate (Late Triassic, Norian to Rhaetian) |
England (Bristol) |
Originally mistakenly believed to be from Australia |  |
| Agujaceratops[50] | - Spencer G. Lucas - Robert M. Sullivan - Adrian P. Hunt |
2006 | Aguja Formation (Late Cretaceous, Campanian) |
United States ( Texas) |
The type species was originally assigned to Chasmosaurus |  |
| Agustinia[51] | - José F. Bonaparte | 1999 | Lohan Cura Formation (Early Cretaceous, Aptian to Albian) |
Argentina (  Neuquén) |
Originally described as possessing long spines running down its back, but these were based on fragments of other bones |  |
| Ahshislepelta[52] | - Michael E. Burns - Robert M. Sullivan |
2011 | Kirtland Formation (Late Cretaceous, Campanian) |
United States (  New Mexico) |
Relatively small compared to other North American ankylosaurs |  |
| Ajkaceratops[53] | - Attila Ősi - Richard J. Butler - David B. Weishampel |
2010 | Csehbánya Formation (Late Cretaceous, Santonian) |
 Hungary(  Veszprém) |
Originally considered a ceratopsian but this is doubtful |  |
| Ajnabia[54] | - Nicholas R. Longrich - Xabier Pereda-Suberbiola - R. Alexander Pyron - Nour-Eddine Jalil |
2021 | Couche III (Late Cretaceous, Maastrichtian) |
Morocco (Béni Mellal-Khénifra) |
The first hadrosaurid named from Africa |  |
| Akainacephalus[55] | - Jelle P. Wiersma - Randall B. Irmis |
2018 | Kaiparowits Formation (Late Cretaceous, Campanian) |
United States ( Utah) |
Much of the skeleton is known, including the entirety of the skull | .png) |
| Akharhynchus[56] | - Megan L. Jacobs - Roy E. Smith - Samir Zouhri |
2025 | Ifezouane Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
Morocco (Drâa-Tafilalet) |
Similar to, contemporary with, and closely related to Siroccopteryx | .jpg) |
| Alamitornis[57] | - Federico L. Agnolín - Agustín G. Martinelli |
2009 | Los Alamitos Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina ( Río Negro) |
Named as a tiny bird but may represent a squamate | |
| Alamodactylus[58] | - Brian Andres - Timothy S. Myers |
2012 | Atco Formation (Late Cretaceous, Coniacian) |
United States ( Texas) |
Represents a rare pteranodontoid pterosaur from the Coniacian | |
| Alamosaurus[59] | - Charles W. Gilmore | 1922 | Ojo Alamo Formation (Late Cretaceous, Maastrichtian) |
United States ( New Mexico) |
The first confirmed titanosaur known to have lived in North America |  |
| Alanqa[60] | - Nizar Ibrahim - David M. Unwin - David M. Martill - Lahssen Baidder - Samir Zouhri |
2010 | Ifezouane Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
Morocco (Drâa-Tafilalet) |
Several pterosaur specimens from the Kem Kem Group were once assigned to this genus |  |
| Alaskacephale[61] | - Robert M. Sullivan | 2006 | Prince Creek Formation (Late Cretaceous, Campanian to Maastrichtian) |
United States (  Alaska) |
Had a double row of nodules on its squamosal |  |
| Albadraco[62] | - Álexandru A. Solomon - Vlad A. Codrea - Márton Venczel - Gerald Grellet-Tinner |
2020 | Șard Formation (Late Cretaceous, Maastrichtian) |
 Romania(Alba) |
Large but not as big as the contemporary Hatzegopteryx |  |
| Albalophosaurus[63] | - Tomoyuki Ohashi - Paul M. Barrett |
2009 | Kuwajima Formation (Early Cretaceous, Barremian) |
 Japan(  Ishikawa) |
Only known from fragments of a skull |  |
| Albertaceratops[64] | - Michael J. Ryan | 2007 | Oldman Formation (Late Cretaceous, Campanian) |
Canada ( Alberta) |
Unlike most centrosaurines, it possessed long brow horns and only a short boss above the nose |  |
| Albertadromeus[65] | - Caleb M. Brown - David C. Evans - Michael J. Ryan - Anthony P. Russell |
2013 | Oldman Formation (Late Cretaceous, Campanian) |
Canada ( Alberta) |
The proportions of its hindlimb suggest a cursorial lifestyle |  |
| Albertavenator[66] | - David C. Evans - Thomas M. Cullen - Derek W. Larson - Adam Rego |
2017 | Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian) |
Canada ( Alberta) |
Its discovery suggests that the true diversity of small theropods may be larger than previously thought |  |
| Albertonykus[67] | - Nicholas R. Longrich - Philip J. Currie |
2009 | Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian) |
Canada ( Alberta) |
May have used its specialized forelimbs to dig into tree trunks for wood-boring termites |  |
| Albertosaurus[68] | - Henry F. Osborn | 1905 | Horseshoe Canyon Formation (Late Cretaceous, Maastrichtian) |
Canada ( Alberta) |
Known from more than thirty specimens, at least twenty-six of which have been preserved together |  |
| Albinykus[69] | - Sterling J. Nesbitt - Julia A. Clarke - Alan H. Turner - Mark A. Norell |
2011 | Javkhlant Formation (Late Cretaceous, Santonian to Campanian) |
Mongolia ( Dornogovi) |
Preserved in a sitting position not unlike that of modern birds |  |
| Alcione[70] | - Nicholas R. Longrich - David M. Martill - Brian Andres |
2018 | Couche III (Late Cretaceous, Maastrichtian) |
Morocco (Béni Mellal-Khénifra) |
Had shortened wings which may be an adaptation for diving |  |
| Alcmonavis[71] | - Oliver W. M. Rauhut - Helmut Tischlinger - Christian Foth |
2019 | Mörnsheim Formation (Late Jurassic, Tithonian) |
Germany ( Bavaria) |
Contemporary with Archaeopteryx but belongs to a separate lineage of avialans |  |
| Alcovasaurus[72] | - Peter M. Galton - Kenneth Carpenter |
2016 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Wyoming) |
Originally named as a species of Stegosaurus but was in fact more closely related to Dacentrurus |  |
| Alectrosaurus[73] | - Charles W. Gilmore | 1933 | Iren Dabasu Formation (Late Cretaceous, Turonian to Maastrichtian) |
China (Inner Mongolia) |
Had long legs that were likely an adaptation to pursuit predation |  |
| Alethoalaornis[74] | - Li Li - Dongyu Hu - Ye Duan - Enpu Gong - Lianhai Hou |
2007 | Jiufotang Formation (Early Cretaceous, Aptian) |
China (Liaoning) |
A poorly known enantiornithean |  |
| Aletopelta[75] | - Tracy L. Ford - James Ian Kirkland |
2001 | Point Loma Formation (Late Cretaceous, Campanian) |
United States (  California) |
Would have lived in present-day Mexico, but was found in California due to plate tectonics |  |
| Alexornis[76] | - Pierce Brodkorb | 1976 | La Bocana Roja Formation (Late Cretaceous, Cenomanian to Turonian) |
Mexico (  Baja California) |
Once thought to have been an ancient relative of rollers and woodpeckers |  |
| Algoasaurus[77] | - Robert Broom | 1904 | Kirkwood Formation (Early Cretaceous, Berriasian to Hauterivian) |
South Africa ( Eastern Cape) |
Originally known from several bones, but most were turned into bricks before they could be studied |  |
| Alioramus[78] | - Sergei M. Kurzanov | 1976 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Possessed a long snout with a row of short crests |  |
| Allkaruen[79] | - Laura Codorniú - Ariana Paulina-Carabajal - Diego Pol - David M. Unwin - Oliver W. M. Rauhut |
2016 | Cañadón Asfalto Formation (Early Jurassic, Toarcian) |
Argentina ( Chubut) |
Known from a very well-preserved braincase |  |
| Allosaurus[80] | - Othniel C. Marsh | 1877 | Alcobaça Formation (Late Jurassic, Oxfordian to Kimmeridgian) Lourinhã Formation (Late Jurassic, Kimmeridgian) Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian)* |
 Portugal(Leiria Lisbon) United States(  Colorado* Oklahoma Utah Wyoming) |
Multiple specimens representing four species have been named, making it well-known both popularly and scientifically |  |
| Almas[81] | - Rui Pei - Mark A. Norell - Daniel E. Barta - Gabriel S. Bever - Michael Pittman - Xing Xu |
2017 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
Preserved alongside eggshells that may have come from a troodontid |  |
| Alnashetri[82] | - Peter J. Makovicky - Sebastián Apesteguía - Federico A. Gianechini |
2012 | Candeleros Formation (Late Cretaceous, Cenomanian) |
Argentina ( Río Negro) |
The oldest known alvarezsauroid from South America |  |
| Alocodon[83] | - Richard A. Thulborn | 1973 | Cabaços Formation (Late Jurassic, Oxfordian) |
Portugal (Leiria) |
Had vertical grooves on its teeth |  |
| Alpkarakush[84] | - Oliver W. M. Rauhut - Aizek A. Bakirov - Oliver Wings - Alexandra E. Fernandes - Tom R. Hübner |
2024 | Balabansai Formation (Middle Jurassic, Bathonian to Callovian) |
 Kyrgyzstan(Jalal-Abad) |
Distinguished from other metriacanthosaurids by its unique orbital brow |  |
| Altirhinus[85] | - David B. Norman | 1998 | Khuren Dukh Formation (Early Cretaceous, Aptian to Albian) |
Mongolia ( Dornogovi) |
Had a distinctly elevated nasal bone that supported an enlarged nasal cavity |  |
| Altispinax[86] | - Friedrich von Huene | 1923 | Wadhurst Clay Formation (Early Cretaceous, Valanginian) |
England (  East Sussex) |
Possessed elongated neural spines that may have supported a hump-like structure as in Concavenator |  |
| Altmuehlopterus[87] | - Steven U. Vidovic - David M. Martill |
2018 | Mörnsheim Formation (Late Jurassic, Tithonian) |
Germany ( Bavaria) |
Possibly a synonym of Germanodactylus |  |
| Alvarezsaurus[88] | - José F. Bonaparte | 1991 | Bajo de la Carpa Formation (Late Cretaceous, Santonian) |
Argentina ( Neuquén) |
One of the largest known alvarezsaurids |  |
| Alwalkeria[89] | - Sankar Chatterjee - Benjamin S. Creisler |
1994 | Lower Maleri Formation (Late Triassic, Carnian to Norian) |
 India(Andhra Pradesh) |
May represent a chimera of dinosaurian, crurotarsan, and "prolacertiform" material |  |
| Alxasaurus[90] | - Dale A. Russell - Zhiming Dong |
1993 | Bayin-Gobi Formation (Early Cretaceous, Albian) |
China (Inner Mongolia) |
Most of the skeleton is known, allowing researchers to connect therizinosaurs to other theropods |  |
| Amanasaurus[91] | - Rodrigo T. Müller - Maurício S. Garcia |
2023 | Candelária Sequence (Late Triassic, Carnian) |
Brazil (  Rio Grande do Sul) |
Named after the Carnian pluvial episode |  |
| Amanzia[92] | - Daniela Schwarz - Philip D. Mannion - Oliver Wings - Christian A. Meyer |
2020 | Reuchenette Formation (Late Jurassic, Kimmeridgian) |
 Switzerland(  Bern) |
One bone preserves fossilized cartilage |  |
| Amargasaurus[93] | - Leonardo Salgado - José F. Bonaparte |
1991 | La Amarga Formation (Early Cretaceous, Barremian to Aptian) |
Argentina ( Neuquén) |
Possessed two rows of backward-pointing spines on its neck that may have been covered by a skin sail |  |
| Amargatitanis[94] | - Sebastián Apesteguía | 2007 | La Amarga Formation (Early Cretaceous, Barremian to Aptian) |
Argentina ( Neuquén) |
Originally described as a titanosaur but has since been reinterpreted as a dicraeosaurid |  |
| Amazonsaurus[95] | - Ismar de Souza Carvalho - Leonardo dos Santos Avilla - Leonardo Salgado |
2003 | Itapecuru Formation (Early Cretaceous to Late Cretaceous, Aptian to Cenomanian) |
Brazil (  Maranhão) |
Had tall caudal neural spines |  |
| Ambiortus[96] | - Evgeny N. Kurochkin | 1982 | Andaikhudag Formation (Early Cretaceous, Hauterivian to Barremian) |
Mongolia (  Bayankhongor) |
Once considered to be an early palaeognath | |
| Amblydectes[97] | - Reginald W. Hooley | 1914 | Cambridge Greensand (Early Cretaceous, Albian) |
England ( Cambridgeshire) |
Closely related to Southern Hemisphere anhanguerids |  |
| Ambopteryx[98] | - Min Wang - Jingmai K. O'Connor - Xing Xu - Zhonghe Zhou |
2019 | Haifanggou Formation (Late Jurassic, Oxfordian) |
China (Liaoning) |
Preserves stomach contents including gastroliths and bone fragments, suggesting an omnivorous diet |  |
| Ampelognathus[99] | - Ronald S. Tykoski - Dori L. Contreras - Christopher Noto |
2023 | Lewisville Formation (Late Cretaceous, Cenomanian) |
United States ( Texas) |
May be a primitive rhabdodontomorph |  |
| Ampelosaurus[100] | - Jean Le Loeuff | 1995 | Marnes Rouges Inférieures Formation (Late Cretaceous, Maastrichtian) |
France (  Occitania) |
Had different types of osteoderms, including spines, plates, and bulbs |  |
| Amphicoelias[101] | - Edward D. Cope | 1877 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado) |
Originally believed to date from the Cretaceous |  |
| Amtocephale[102] | - Mahito Watabe - Khishigjav Tsogtbaatar - Robert M. Sullivan |
2011 | Bayanshiree Formation (Late Cretaceous, Cenomanian to Coniacian) |
Mongolia ( Ömnögovi) |
One of the oldest known pachycephalosaurs |  |
| Amtosaurus[103] | - Sergei M. Kurzanov - Tatyana A. Tumanova |
1978 | Bayanshiree Formation (Late Cretaceous, Cenomanian to Coniacian) |
Mongolia ( Ömnögovi) |
May be either a hadrosaurid or an ankylosaurid | |
| Amurosaurus[104] | - Yuri L. Bolotsky - Sergei M. Kurzanov |
1991 | Udurchukan Formation (Late Cretaceous, Maastrichtian)* Yuliangze Formation (Late Cretaceous, Maastrichtian) |
China (Heilongjiang)  Russia(  Amur Oblast*) |
One specimen may have come from an individual with a limp |  |
| Amygdalodon[105] | - Angel Cabrera | 1947 | Cerro Carnerero Formation (Early Jurassic, Toarcian) |
Argentina ( Chubut) |
Its teeth were shaped like almonds |  |
| Anabisetia[106] | - Rodolfo A. Coria - Jorge O. Calvo |
2002 | Lisandro Formation (Late Cretaceous, Turonian) |
Argentina ( Neuquén) |
Four specimens are known but do not include much skull material |  |
| Analong[107] | - Xinxin Ren - Toru Sekiya - Tao Wang - Zhiwen Yang - Hailu You |
2021 | Chuanjie Formation (Middle Jurassic, Aalenian to Bajocian) |
China (Yunnan) |
Originally described as a specimen of Chuanjiesaurus but was given its own genus due to several morphological differences |  |
| Anasazisaurus[108] | - Adrian P. Hunt - Spencer G. Lucas |
1993 | Kirtland Formation (Late Cretaceous, Campanian) |
United States ( New Mexico) |
May have been a second species of Kritosaurus |  |
| Anatalavis[109] | - Storrs L. Olson - David C. Parris |
1987 | Hornerstown Formation (Late Cretaceous to Paleocene, Maastrichtian to Danian)* London Clay (Eocene, Ypresian) |
England (  Essex) United States(  New Jersey*) |
It is uncertain if the type species came from Cretaceous or Paleogene sediments | |
| Anchiceratops[110] | - Barnum Brown | 1914 | Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian) |
Canada ( Alberta) |
Had a long triangular frill ringed by small triangular spikes |  |
| Anchiornis[111] | - Xing Xu - Qi Zhao - Mark A. Norell - Corwin Sullivan - David W. E. Hone - Gregory M. Erickson - Xiaolin Wang - Fenglu Han - Yu Guo |
2009 | Tiaojishan Formation (Late Jurassic, Oxfordian) |
China (Liaoning) |
Analysis of fossilized melanosomes suggest it had a dark gray body, black and white patterns on the wings, and a red head crest |  |
| Anchisaurus[112] | - Othniel C. Marsh | 1885 | Portland Formation (Early Jurassic, Hettangian to Sinemurian) |
United States (  Connecticut* Massachusetts) |
Some possible remains were originally misidentified as human skeletons |  |
| Andesaurus[113] | - Jorge O. Calvo - José F. Bonaparte |
1991 | Candeleros Formation (Late Cretaceous, Cenomanian) |
Argentina ( Neuquén) |
One of the most basal members of the Titanosauria |  |
| Angolatitan[114] | - Octávio Mateus - Louis L. Jacobs - Anne S. Schulp - Michael J. Polcyn - Tatiana S. Tavares - André B. Neto - Maria L. Morais - Miguel T. Antunes |
2011 | Itombe Formation (Late Cretaceous, Coniacian) |
 Angola(Bengo) |
The first non-avian dinosaur described from Angola |  |
| Angulomastacator[115] | - Jonathan R. Wagner - Thomas M. Lehman |
2009 | Aguja Formation (Late Cretaceous, Campanian) |
United States ( Texas) |
The anterior tip of its jaw was angled 45º downward, with the tooth row bent to match |  |
| Angustinaripterus[116] | - Xinlu He - Daihuan Yang - Chunkang Su |
1983 | Xiashaximiao Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
China (Sichuan) |
Had a long, flat snout with interlocking teeth that may have been used to trap fish |  |
| Anhanguera[117] | - Diogenes A. Campos - Alexander W. A. Kellner |
1985 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil (  Ceará) |
A study of its inner ear shows that it held its head at an angle to the ground |  |
| Anhuilong[118] | - Xinxin Ren - Jiandong Huang - Hailu You |
2020 | Hongqin Formation (Middle Jurassic, Aalenian to Callovian) |
China (Anhui) |
Closely related to Huangshanlong and Omeisaurus, with which it forms an exclusive clade of mamenchisaurids |  |
| Aniksosaurus[119] | - Rubén D. F. Martínez - Fernando E. Novas |
2006 | Bajo Barreal Formation (Late Cretaceous, Cenomanian to Turonian) |
Argentina ( Chubut) |
Several remains were found in a bone bed, suggesting a gregarious lifestyle |  |
| Animantarx[120] | - Kenneth Carpenter - James I. Kirkland - Donald L. Burge - John Bird |
1999 | Cedar Mountain Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
United States ( Utah) |
Its fossils were discovered by tracking the radiation they gave off, not by excavating a partially exposed skeleton |  |
| Ankylosaurus[121] | - Barnum Brown | 1908 | Ferris Formation (Late Cretaceous, Maastrichtian) Frenchman Formation (Late Cretaceous, Maastrichtian) Hell Creek Formation (Late Cretaceous, Maastrichtian)* Lance Formation (Late Cretaceous, Maastrichtian) Scollard Formation (Late Cretaceous, Maastrichtian) |
Canada ( Alberta Saskatchewan) United States( Montana* Wyoming) |
The largest and most well-known ankylosaur |  |
| Anodontosaurus[122] | - Charles M. Sternberg | 1929 | Dinosaur Park Formation (Late Cretaceous, Campanian) Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian)* |
Canada ( Alberta) |
Originally mistakenly believed to have been toothless |  |
| Anomalipes[123] | - Yilun Yu - Kebai Wang - Shuqing Chen - Corwin Sullivan - Shuo Wang - Peiye Wang - Xing Xu |
2018 | Wangshi Group (Late Cretaceous, Campanian) |
China (Shandong) |
May have been closely related to Gigantoraptor despite its smaller size |  |
| Anoplosaurus[124] | - Harry G. Seeley | 1879 | Cambridge Greensand (Early Cretaceous, Albian) |
England ( Cambridgeshire) |
Considered an ankylosaur despite the fact that no osteoderms have been found | .jpg) |
| Anserimimus[125] | - Rinchen Barsbold | 1988 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Had powerful forelimbs with uniquely straight, flattened claws |  |
| Antarcticavis[126] | - Amanda Cordes-Person - Carolina Acosta Hospitaleche - Judd Case - James Martin |
2020 | Snow Hill Island Formation (Late Cretaceous, Maastrichtian) |
 Antarctica(  Argentine Antarctica British Antarctic Territory Chilean Antarctic Territory) |
The oldest bird known from Antarctica | |
| Antarctopelta[127] | - Leonardo Salgado - Zulma Gasparini |
2006 | Snow Hill Island Formation (Late Cretaceous, Maastrichtian) |
Antarctica ( Argentine Antarctica British Antarctic Territory Chilean Antarctic Territory) |
Possessed unusual caudal vertebrae that may have supported a "macuahuitl" as in the related Stegouros |  |
| Antarctosaurus[128] | - Friedrich von Huene | 1929 | Anacleto Formation (Late Cretaceous, Campanian) |
Argentina ( Río Negro) |
Multiple specimens have been referred to this genus, but so far only the holotype can be confidently assigned to it |  |
| Antetonitrus[129] | - Adam M. Yates - James W. Kitching |
2003 | Upper Elliot Formation (Early Jurassic, Sinemurian to Pliensbachian) |
South Africa ( Free State) |
Had weight-bearing adaptations in all its limbs, although its forelimbs retain some adaptations for grasping |  |
| Antrodemus[130] | - Joseph Leidy | 1870 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado) |
Although unconfirmed, it may be the same creature as Allosaurus, in which case the name Antrodemus will have priority |  |
| Anurognathus[131] | - Ludwig Döderlein | 1923 | Altmühltal Formation (Late Jurassic, Tithonian) |
Germany ( Bavaria) |
Had large eyes and long wings that suggest it was a crepuscular hunter that caught insects on the wing |  |
| Anzu[132] | - Matthew C. Lamanna - Hans-Dieter Sues - Emma R. Schachner - Tyler R. Lyson |
2014 | Hell Creek Formation (Late Cretaceous, Maastrichtian) |
United States ( Montana North Dakota South Dakota*) |
Large and known from considerably complete remains |  |
| Aoniraptor[133] | - Matías J. Motta - Alexis Mauro Aranciaga Rolando - Sebastián Rozadilla - Federico L. Agnolín - Nicolás R. Chimento - Federico Brissón-Eglí - Fernando E. Novas |
2016 | Huincul Formation (Late Cretaceous, Cenomanian to Turonian) |
Argentina ( Río Negro) |
Usually seen as a megaraptoran but has been considered a relative of the enigmatic Bahariasaurus |  |
| Aorun[134] | - Jonah N. Choiniere - James M. Clark - Catherine A. Forster - Mark A. Norell - David A. Eberth - Gregory M. Erickson - Hongjun Chu - Xing Xu |
2014 | Shishugou Formation (Middle Jurassic to Late Jurassic, Callovian to Oxfordian) |
China (Xinjiang) |
Potentially a basal member of the alvarezsaurian lineage |  |
| Apatodon[135] | - Othniel C. Marsh | 1877 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado) |
Originally misidentified as the jawbone of a pig, but may be an Allosaurus vertebra instead |  |
| Apatoraptor[136] | - Gregory F. Funston - Philip J. Currie |
2016 | Horseshoe Canyon Formation (Late Cretaceous, Campanian) |
Canada ( Alberta) |
Quill knobs on its ulna suggest it had wings |  |
| Apatorhamphus[137] | - James McPhee - Nizar Ibrahim - Alex Kao - David M. Unwin - Roy Smith - David M. Martill |
2020 | Ifezouane Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
Morocco (Drâa-Tafilalet) |
Named based on isolated jaw bones once assigned to different pterosaur groups |  |
| Apatornis[138] | - Othniel C. Marsh | 1873 | Niobrara Formation (Late Cretaceous, Coniacian to Campanian) |
United States (  Kansas) |
Only known from an isolated synsacrum |  |
| Apatosaurus[80] | - Othniel C. Marsh | 1877 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado* New Mexico Oklahoma Utah Wyoming) |
Its skeleton was more robust than those of most diplodocids |  |
| Appalachiosaurus[139] | - Thomas D. Carr - Thomas E. Williamson - David R. Schwimmer |
2005 | Demopolis Chalk (Late Cretaceous, Campanian)* Donoho Creek Formation (Late Cretaceous, Campanian) Tar Heel/Coachman Formation (Late Cretaceous, Campanian) |
United States (  Alabama* North Carolina South Carolina) |
The most complete theropod known from the eastern side of North America |  |
| Apsaravis[140] | - Mark A. Norell - Julia A. Clarke |
2001 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
The first basal ornithurine named from a desert environment | |
| Aquilarhinus[141] | - Albert Prieto-Márquez - Jonathan R. Wagner - Thomas M. Lehman |
2020 | Aguja Formation (Late Cretaceous, Campanian) |
United States ( Texas) |
May have been a semiaquatic coastal species that used its shovel-shaped bill to scoop up vegetation in wet sediment |  |
| Aquilops[142] | - Andrew A. Farke - W. Desmond Maxwell - Richard L. Cifelli - Mathew J. Wedel |
2014 | Cloverly Formation (Early Cretaceous, Albian) |
United States ( Montana) |
Had a short horn protruding from its upper beak |  |
| Arackar[143] | - David Rubilar-Rogers - Alexander O. Vargas - Bernardo Javier González Riga - Sergio Soto-Acuña - Jhonatan Alarcón-Muñoz - José Iriarte-Díaz - Carlos Arévalo - Carolina Simon-Gutstein |
2021 | Hornitos Formation (Late Cretaceous, Campanian to Maastrichtian) |
 Chile(  Atacama) |
The most complete sauropod known from Chile |  |
| Aragosaurus[144] | - José L. Sanz - Angela D. Buscalioni - Maria Lourdes Casanovas-Cladellas - José V. Santafé |
1987 | Villar del Arzobispo Formation (Late Jurassic to Early Cretaceous, Tithonian to Berriasian) |
Spain (  Aragon) |
Named after its unique ischium anatomy |  |
| Aralazhdarcho[145] | - Alexander O. Averianov | 2007 | Bostobe Formation (Late Cretaceous, Santonian to Campanian) |
 Kazakhstan(Kyzylorda) |
One of the more primitive azhdarchids |  |
| Aralosaurus[146] | - Anatoly K. Rozhdestvensky | 1968 | Bostobe Formation (Late Cretaceous, Santonian to Campanian) |
Kazakhstan (Kyzylorda) |
Its crest has been interpreted as being arch-shaped as in kritosaurins, but this cannot be confirmed |  |
| Arambourgiania[147] | - Lev A. Nessov | 1984 | Ruseifa Formation (Late Cretaceous, Maastrichtian) |
 Jordan(Zarqa) |
Several specimens from Africa and North America have been assigned to this giant pterosaur, but it is uncertain if they belong to the type species |  |
| Araripedactylus[148] | - Peter Wellnhofer | 1977 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
One of the first pterosaurs named from Brazil | |
| Araripesaurus[149] | - Llewellyn I. Price | 1971 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
Fragmentary but similar to some specimens of Anhanguera | |
| Aratasaurus[150] | - Juliana M. Sayão - Antônio Á. F. Saraiva - Arthur S. Brum - Renan A. M. Bantim - Rafael C. L. P. de Andrade - Xin Cheng - Flaviana J. de Lima - Helder P. Silva - Alexander W. A. Kellner |
2020 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
All three of its toes are symmetric |  |
| Archaeoceratops[151] | - Zhiming Dong - Yoichi Azuma |
1997 | Xiagou Formation (Early Cretaceous, Aptian) Zhonggou Formation (Early Cretaceous, Aptian)* |
China (Gansu) |
Had no horns and only the beginnings of a frill |  |
| Archaeocursor[152] | - Xi Yao - Qi Zhao - Tingcong Ren - Guangbiao Wei - Xing Xu |
2025 | Ziliujing Formation (Early Jurassic, Sinemurian to Toarcian) |
China (Chongqing) |
The oldest and most primitive ornithischian from Asia |  |
| Archaeodontosaurus[153] | - Eric Buffetaut | 2005 | Isalo III Formation (Middle Jurassic, Bajocian to Bathonian) |
 Madagascar(Boeny) |
Retained teeth similar to primitive sauropodomorphs despite its late age and derived position |  |
| Archaeoistiodactylus[154] | - Junchang Lü - Xiaohui Fucha |
2010 | Tiaojishan Formation (Late Jurassic, Oxfordian) |
China (Liaoning) |
Described as an early Istiodactylus relative but may actually be closer to Darwinopterus | |
| Archaeopteryx[155] | - Hermann von Meyer | 1861 | Altmühltal Formation (Late Jurassic, Tithonian)* Mörnsheim Formation (Late Jurassic, Tithonian) |
Germany ( Bavaria) |
Combines bird-like pennaceous feathers with teeth, claws, and a long tail otherwise characteristic of reptiles |  |
| Archaeorhynchus[156] | - Zhonghe Zhou - Fucheng Zhang |
2006 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
One of the oldest avialans known to have a beak |  |
| Archaeornithoides[157] | - Andrzej Elżanowski - Peter Wellnhofer |
1992 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
Known from a partial skull with scratches that may have been created by a small mammal |  |
| Archaeornithomimus[158] | - Dale A. Russell | 1972 | Iren Dabasu Formation (Late Cretaceous, Turonian to Maastrichtian) |
China (Inner Mongolia) |
Unlike other ornithomimosaurs, its feet were not arctometatarsalian |  |
| Archaeornithura[159] | - Min Wang - Xiaoting Zheng - Jingmai K. O'Connor - Graeme T. Lloyd - Xiaoli Wang - Yan Wang - Xiaomei Zhang - Zhonghe Zhou |
2015 | Huajiying Formation (Early Cretaceous, Hauterivian) |
China (Hebei) |
One of the oldest known ornithuromorphs |  |
| Arcovenator[160] | - Thierry Tortosa - Eric Buffetaut - Nicolas Vialle - Yves Dutour - Eric Turini - Gilles Cheylan |
2014 | Argiles et Grès à Reptiles Formation (Late Cretaceous, Campanian) |
France ( Provence-Alpes-Côte d'Azur) |
Most closely related to abelisaurids from India and Madagascar |  |
| Arcticodactylus[161] | - Alexander W. A. Kellner | 2015 | Ørsted Dal Formation (Late Triassic, Norian to Rhaetian) |
 Greenland(Sermersooq) |
One of the smallest, oldest, and most primitive pterosaurs | |
| Arcusaurus[162] | - Adam M. Yates - Matthew F. Bonnan - Johann Neveling |
2011 | Upper Elliot Formation (Early Jurassic, Sinemurian to Pliensbachian) |
South Africa ( Free State) |
Combines traits of primitive and advanced sauropodomorphs |  |
| Ardeadactylus[163] | - Christopher Bennett | 2013 | Altmühltal Formation (Late Jurassic, Tithonian) Mörnsheim Formation (Late Jurassic, Tithonian) Nusplingen Limestone (Late Jurassic, Kimmeridgian)* |
Germany (  Baden-Württemberg* Bavaria) |
May have eaten larger fish than its smaller contemporary Pterodactylus |  |
| Ardetosaurus[164] | - Tom T.P. van der Linden - Emanuel Tschopp - Roland B. Sookias - Jonathan J.W. Wallaard - Femke M. Holwerda - Anne S. Schulp |
2024 | Morrison Formation (Late Jurassic, Kimmeridgian) |
United States ( Wyoming) |
Its holotype was damaged in a museum fire |  |
| Arenysaurus[165] | - Xabier Pereda-Suberbiola - José Ignacio Canudo - Penélope Cruzado-Caballero - José Luis Barco - Nieves López-Martínez - Oriol Oms - José Ignacio Ruiz-Omeñaca |
2009 | Conques Formation (Late Cretaceous, Maastrichtian) |
Spain ( Aragon) |
One of the last lambeosaurines prior to the extinction of the non-avian dinosaurs |  |
| Argentinadraco[166] | - Alexander W. A. Kellner - Jorge O. Calvo |
2017 | Portezuelo Formation (Late Cretaceous, Turonian to Coniacian) |
Argentina ( Neuquén) |
Had unusual ridges on its lower jaw that may have helped it probe for crustaceans in loose sediment |  |
| Argentinosaurus[167] | - José F. Bonaparte - Rodolfo A. Coria |
1993 | Huincul Formation (Late Cretaceous, Cenomanian to Turonian) |
Argentina ( Neuquén) |
May have been the largest known dinosaur |  |
| Argyrosaurus[168] | - Richard Lydekker | 1893 | Lago Colhué Huapí Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina ( Chubut) |
Several remains were historically assigned to this genus, but only the holotype can be confidently assigned to it |  |
| Aristosuchus[169] | - Harry G. Seeley | 1887 | Wessex Formation (Early Cretaceous, Berriasian to Barremian) |
England (  Isle of Wight) |
Referred unguals suggest this creature had long claws |  |
| Arkansaurus[170] | - Rebecca K. Hunt - James H. Quinn |
2018 | Trinity Group (Early Cretaceous, Aptian to Albian) |
United States (  Arkansas) |
Its scientific name was in use long before its formal description |  |
| Arkharavia[171] | - Vladimir R. Alifanov - Yuri L. Bolotsky |
2010 | Udurchukan Formation (Late Cretaceous, Maastrichtian) |
Russia ( Amur Oblast) |
Described from a series of vertebrae, several of which may not belong to this taxon |  |
| Arrhinoceratops[172] | - William A. Parks | 1925 | Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian) |
Canada ( Alberta) |
Described as lacking a nasal horn although this is an artifact of preservation |  |
| Arrudatitan[173] | - Julian C.G. Silva Junior - Agustín G. Martinelli - Fabiano V. Iori - Thiago S. Marinho - E. Martín Hechenleitner - Max C. Langer |
2022 | Adamantina Formation (Late Cretaceous, Coniacian to Maastrichtian) |
Brazil ( São Paulo) |
Its tail probably curved strongly downwards, with the tip held very low to the ground |  |
| Arstanosaurus[174] | - P. V. Shilin - Yu. V. Suslov |
1982 | Bostobe Formation (Late Cretaceous, Santonian to Campanian) |
Kazakhstan (Kyzylorda) |
A poorly known possible hadrosauroid |  |
| Arthurdactylus[175] | - Eberhard Frey - David M. Martill |
1994 | Crato Formation (Early Cretaceous, Aptian) |
Brazil ( Ceará) |
The first pterosaur described from the Crato Formation | |
| Asfaltovenator[176] | - Oliver W. M. Rauhut - Diego Pol |
2019 | Cañadón Asfalto Formation (Early Jurassic, Toarcian) |
Argentina ( Chubut) |
Combines traits of megalosauroid and allosauroid theropods |  |
| Asiaceratops[177] | - Lev A. Nessov - L. F. Kaznyshkina - G. O. Cherepanov |
1989 | Khodzhakul Formation (Late Cretaceous, Cenomanian) |
Uzbekistan (  Karakalpakstan) |
Potentially a leptoceratopsid |  |
| Asiahesperornis[178] | - Lev A. Nessov - B. V. Prizemlin |
1991 | Zhuravlovskaya Svita (Late Cretaceous, Maastrichtian) |
Kazakhstan (Kostanay) |
Similar to Hesperornis | |
| Asiamericana[179] | - Lev A. Nessov | 1995 | Bissekty Formation (Late Cretaceous, Turonian) |
Uzbekistan (Navoiy) |
Has been suggested to be a fish, a spinosaurid, or a species of Richardoestesia |  |
| Asiatosaurus[180] | - Henry F. Osborn | 1924 | Öösh Formation (Early Cretaceous, Berriasian to Barremian)* Xinlong Formation (Early Cretaceous, Aptian to Albian) |
China (Guangxi) Mongolia(  Övörkhangai*) |
Two species are known but both are only known from scant remains |  |
| Asiatyrannus[181] | - Wenjie Zheng - Xingsheng Jin - Junfang Xie - Tianming Du |
2024 | Nanxiong Formation (Late Cretaceous, Maastrichtian) |
China (Jiangxi) |
Known from an individual initially interpreted as a small adult, but may be a juvenile of a larger species |  |
| Asilisaurus[182] | - Sterling J. Nesbitt - Christian A. Sidor - Randall B. Irmis - Kenneth D. Angielczyk - Roger M. H. Smith - Linda A. Tsuji |
2010 | Manda Formation (Middle Triassic to Late Triassic, Anisian to Carnian) |
 Tanzania(Ruvuma) |
May be one of the oldest bird-line archosaurs |  |
| Asteriornis[183] | - Daniel J. Field - Juan Benito - Albert Chen - John W. M. Jagt - Daniel T. Ksepka |
2020 | Maastricht Formation (Late Cretaceous, Maastrichtian) |
 Belgium(  Wallonia) |
The most complete crown-group bird known from the Mesozoic, providing a lot of information about their early evolution |  |
| Astrodon[184] | - Joseph Leidy | 1865 | Arundel Formation (Early Cretaceous, Aptian to Albian) |
United States ( Maryland) |
State dinosaur of Maryland |  |
| Astrophocaudia[185] | - Michael D. D'Emic | 2013 | Paluxy Formation (Early Cretaceous, Albian) |
United States ( Texas) |
Known from a single partial skeleton |  |
| Asylosaurus[186] | - Peter M. Galton | 2007 | Magnesian Conglomerate (Late Triassic, Norian to Rhaetian) |
England (Bristol) |
Remains originally identified as Thecodontosaurus |  |
| Atacamatitan[187] | - Alexander W. A. Kellner - David Rubilar-Rogers - Alexander O. Vargas - Mario Suárez |
2011 | Tolar Formation (Late Cretaceous, Cenomanian to Maastrichtian) |
Chile (  Antofagasta) |
Only known from a single, fragmentary skeleton |  |
| Atlantosaurus[80] | - Othniel C. Marsh | 1877 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado) |
The type species may be synonymous with Apatosaurus, but a referred one may belong to its own genus |  |
| Atlasaurus[188] | - Michel Monbaron - Dale A. Russell - Philippe Taquet |
1999 | Guettioua Formation (Middle Jurassic, Bathonian to Callovian) |
Morocco (Béni Mellal-Khénifra) |
Possessed proportionately long legs for a sauropod |  |
| Atlascopcosaurus[189] | - Thomas H. Rich - Patricia Vickers-Rich |
1989 | Eumeralla Formation (Early Cretaceous, Aptian to Albian) |
 Australia(  Victoria) |
Only known from remains of jaws and teeth |  |
| Atrociraptor[190] | - Philip J. Currie - David J. Varricchio |
2004 | Horseshoe Canyon Formation (Late Cretaceous, Campanian to Maastrichtian) |
Canada ( Alberta) |
Had a short, deep snout with enlarged teeth |  |
| Atsinganosaurus[191] | - Géraldine Garcia - Sauveur Amico - Francois Fournier - Eudes Thouand - Xavier Valentin |
2010 | Argiles et Grès à Reptiles Formation (Late Cretaceous, Campanian) |
France ( Provence-Alpes-Côte d'Azur) |
Belongs to the Lirainosaurinae, a group of titanosaurs endemic to southern Europe and northern Africa during the Late Cretaceous |  |
| Aublysodon[192] | - Joseph Leidy | 1868 | Judith River Formation (Late Cretaceous, Campanian) |
United States ( Montana) |
Only known from teeth that may come from juvenile tyrannosaurids |  |
| Aucasaurus[193] | - Rodolfo A. Coria - Luis M. Chiappe - Lowell Dingus |
2002 | Anacleto Formation (Late Cretaceous, Campanian) |
Argentina ( Neuquén) |
Known from most of the skeleton, including most of the skull |  |
| Augustynolophus[194] | - Albert Prieto-Márquez - Jonathan R. Wagner - Phil R. Bell - Luis M. Chiappe |
2015 | Moreno Formation (Late Cretaceous, Maastrichtian) |
United States ( California) |
State dinosaur of California |  |
| Auroraceratops[195] | - Hailu You - Daqing Li - Qiang Ji - Matthew C. Lamanna - Peter Dodson |
2005 | Zhonggou Formation (Early Cretaceous, Aptian) |
China (Gansu) |
Known from more than eighty specimens, including complete skeletons |  |
| Aurorazhdarcho[196] | - Eberhard Frey - Christian A. Meyer - Helmut Tischlinger |
2011 | Altmühltal Formation (Late Jurassic, Tithonian) |
Germany ( Bavaria) |
May represent juvenile specimens of Gnathosaurus |  |
| Aurornis[197] | - Pascal Godefroit - Andrea Cau - Dongyu Hu - François Escuillié - Wenhao Wu - Gareth J. Dyke |
2013 | Tiaojishan Formation (Late Jurassic, Oxfordian) |
China (Liaoning) |
If an avialan as originally described, it would be one of the oldest members of the group |  |
| Aussiedraco[198] | - Alexander W. A. Kellner - Taissa Rodrigues - Fabiana R. Costa |
2011 | Toolebuc Formation (Early Cretaceous, Albian) |
Australia (  Queensland) |
Originally believed to be a specimen of Ornithocheirus, Lonchodectes, or Anhanguera |  |
| Austinornis[199] | - Julia A. Clarke | 2004 | Austin Chalk (Late Cretaceous, Coniacian to Santonian) |
United States ( Texas) |
May be a pangalliform, but this is uncertain | |
| Australodocus[200] | - Kristian Remes | 2007 | Tendaguru Formation (Late Jurassic, Tithonian) |
Tanzania (Lindi) |
Potentially an early euhelopodid |  |
| Australotitan[201] | - Scott A. Hocknull - Melville Wilkinson - Rochelle A. Lawrence - Vladislav Konstantinov - Stuart Mackenzie - Robyn Mackenzie |
2021 | Winton Formation (Late Cretaceous, Cenomanian to Turonian) |
Australia ( Queensland) |
The largest dinosaur specimen known from Australia, comparable in size to some South American dinosaurs |  |
| Australovenator[202] | - Scott A. Hocknull - Matt A. White - Travis R. Tischler - Alex G. Cook - Naomi D. Calleja - Trish Sloan - David A. Elliott |
2009 | Winton Formation (Late Cretaceous, Cenomanian to Turonian) |
Australia ( Queensland) |
Analysis of its arms suggests it was well adapted to grasping |  |
| Austriadactylus[203] | - Fabio M. Dalla Vecchia - Rupert Wild - Hagen Hopf - Joachim Reitner |
2002 | Seefeld Formation (Late Triassic, Norian) |
 Austria(  Tyrol) |
Had a crest on its snout, a rarity for early pterosaurs |  |
| Austriadraco[161] | - Alexander W. A. Kellner | 2015 | Seefeld Formation (Late Triassic, Norian) |
Austria ( Tyrol) |
Similar to Eudimorphodon but contains enough differences to be described as a separate genus | |
| Austrocheirus[204] | - Martín D. Ezcurra - Federico L. Agnolín - Fernando E. Novas |
2010 | Cerro Fortaleza Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina (  Santa Cruz) |
Initially described as an abelisauroid but this is doubted by some researchers |  |
| Austroposeidon[205] | - Kamila L. N. Bandeira - Felipe M. Simbras - Elaine B. Machado - Diogenes A. Campos - Gustavo R. Oliveira - Alexander W. A. Kellner |
2016 | Presidente Prudente Formation (Late Cretaceous, Campanian to Maastrichtian) |
Brazil ( São Paulo) |
One of the largest dinosaurs known from Brazil |  |
| Austroraptor[206] | - Fernando E. Novas - Diego Pol - Juan I. Canale - Juan D. Porfiri - Jorge O. Calvo |
2009 | Allen Formation (Late Cretaceous, Maastrichtian) |
Argentina ( Río Negro) |
Possessed an elongated snout paralleling those of spinosaurids |  |
| Austrosaurus[207] | - Heber A. Longman | 1933 | Allaru Formation (Early Cretaceous, Albian) |
Australia ( Queensland) |
Its fossils were found associated with marine shells |  |
| Avaceratops[208] | - Peter Dodson | 1986 | Judith River Formation (Late Cretaceous, Campanian) |
United States ( Montana) |
Lacked fenestrae in its frill, a feature shared only with Triceratops |  |
| Aviatyrannis[209] | - Oliver W. M. Rauhut | 2003 | Alcobaça Formation (Late Jurassic, Kimmeridgian) |
Portugal (Leiria) |
Although originally described as a tyrannosauroid, it may in fact be the oldest known ornithomimosaur |  |
| Avimaia[210] | - Alida M. Bailleul - Jingmai K. O'Connor - Shukang Zhang - Zhiheng Li - Qiang Wang - Matthew C. Lamanna - Xufeng Zhu - Zhonghe Zhou |
2019 | Xiagou Formation (Early Cretaceous, Aptian) |
China (Gansu) |
One specimen died with an unlaid egg in its body |  |
| Avimimus[211] | - Sergei M. Kurzanov | 1981 | Djadokhta Formation (Late Cretaceous, Campanian)* Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Bonebed remains suggest it was at least partially gregarious, probably forming age-segregated leks or flocks |  |
| Avisaurus[212] | - Michael K. Brett-Surman - Gregory S. Paul |
1985 | Hell Creek Formation (Late Cretaceous, Maastrichtian) |
United States ( Montana) |
Originally considered a non-avialan dinosaur | .png) |
| Aymberedactylus[213] | - Rodrigo V. Pêgas - Maria Eduarda C. Leal - Alexander W. A. Kellner |
2016 | Crato Formation (Early Cretaceous, Aptian) |
Brazil ( Ceará) |
Known from a three-dimensionally preserved toothless mandible |  |
| Azhdarcho[147] | - Lev A. Nessov | 1984 | Bissekty Formation (Late Cretaceous, Turonian) |
Uzbekistan (Navoiy) |
One of the smallest and earliest unambiguous azhdarchids |  |
| Baalsaurus[214] | - Jorge O. Calvo - Bernardo J. González Riga |
2019 | Portezuelo Formation (Late Cretaceous, Turonian to Coniacian) |
Argentina ( Neuquén) |
Had a squared-off dentary with its teeth crowded to the front |  |
| Bactrosaurus[73] | - Charles W. Gilmore | 1933 | Iren Dabasu Formation (Late Cretaceous, Turonian to Maastrichtian) |
China (Inner Mongolia) |
Remains of at least six individuals are known, making up much of the skeleton |  |
| Bagaceratops[215] | - Teresa Maryańska - Halszka Osmólska |
1975 | Baruungoyot Formation (Late Cretaceous, Maastrichtian)* Bayan Mandahu Formation (Late Cretaceous, Campanian) |
China (Inner Mongolia) Mongolia( Ömnögovi*) |
May have been a direct descendant of Protoceratops which it physically resembles |  |
| Bagaraatan[216] | - Halszka Osmólska | 1996 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
As described, it represented a chimera of tyrannosauroid and caenagnathid bones |  |
| Bagualia[217] | - Diego Pol - J. Ramezani - Kevin L. Gomez - José L. Carballido - Ariana Paulina Carabajal - Oliver W. M. Rauhut - I. H. Escapa - N. R. Cúneo |
2020 | Cañadón Asfalto Formation (Early Jurassic, Toarcian) |
Argentina ( Chubut) |
Represented a radiation of eusauropods that displaced earlier primitive sauropodomorphs after a global warming event | .png) |
| Bagualosaurus[218] | - Flávio A. Pretto - Max C. Langer - Cesar L. Schultz |
2019 | Candelária Sequence (Late Triassic, Carnian) |
Brazil ( Rio Grande do Sul) |
Had relatively robust hind limbs for a basal sauropodomorph |  |
| Bahariasaurus[219] | - Ernst Stromer | 1934 | Bahariya Formation (Late Cretaceous, Cenomanian) |
Egypt ( Giza) |
Large but known from relatively few remains |  |
| Bainoceratops[220] | - Victor S. Tereshchenko - Vladimir R. Alifanov |
2003 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
Its supposedly diagnostic features may fall within Protoceratops variation |  |
| Baiyinosaurus[221] | - Ning Li - Susannah C.R. Maidment - Daqing Li - Hai-Lu You - Guangzhao Peng |
2024 | Wangjiashan Formation (Middle Jurassic, Bathonian) |
China (Gansu) |
Exhibits anatomical characteristics transitional between basal thyreophorans and derived stegosaurs |  |
| Bajadasaurus[222] | - Pablo A. Gallina - Sebastián Apesteguía - Juan I. Canale - Alejandro Haluza |
2019 | Bajada Colorada Formation (Early Cretaceous, Berriasian to Valanginian) |
Argentina ( Neuquén) |
Possessed elongated, forward-pointing spines erupting in pairs from the neck |  |
| Bakonydraco[223] | - Attila Ősi - David B. Weishampel - Coralia M. Jianu |
2005 | Csehbánya Formation (Late Cretaceous, Santonian) |
Hungary ( Veszprém) |
Has been considered a late-surviving tapejarid |  |
| Balaenognathus[224] | - David M. Martill - Eberhard Frey - Helmut Tischlinger - Matthias Mäuser - Héctor E. Rivera-Sylva - Steven U. Vidovic |
2023 | Torleite Formation (Late Jurassic, Kimmeridgian) |
Germany ( Bavaria) |
May have been either a suspension feeder or a gular-pumping filter feeder based on its jaw anatomy | .png) |
| Balaur[225] | - Zoltán Csiki - Mátyás Vremir - Stephen L. Brusatte - Mark A. Norell |
2010 | Densuș-Ciula Formation (Late Cretaceous, Maastrichtian) Sebeș Formation (Late Cretaceous, Maastrichtian)* |
Romania (Alba* Hunedoara) |
Had a suite of unique features, including robust muscles, two sickle claws, a didactyl manus, and a deep gut, which may be results of its island habitat |  |
| Bambiraptor[226] | - David A. Burnham - Kraig Derstler - Philip J. Currie - Robert T. Bakker - Zhonghe Zhou - John H. Ostrom |
2000 | Two Medicine Formation (Late Cretaceous, Campanian) |
United States ( Montana) |
Small but well-preserved enough to display a mix of non-avian and avian features |  |
| Banguela[227] | - Jaime A. Headden - Hebert B. N. Campos |
2015 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
May be a second species of Thalassodromeus |  |
| Banji[228] | - Xing Xu - Fenglu Han |
2010 | Nanxiong Formation (Late Cretaceous, Maastrichtian) |
China (Jiangxi) |
Had vertical striations on its crest |  |
| Bannykus[229] | - Xing Xu - Jonah N. Choiniere - Qingwei Tan - Roger B.J. Benson - James M. Clark - Corwin Sullivan - Qi Zhao - Fenglu Han - Qingyu Ma - Yiming He - Shuo Wang - Hai Xing - Lin Tan |
2018 | Bayin-Gobi Formation (Early Cretaceous, Albian) |
China (Inner Mongolia) |
Exhibited a transitional hand morphology for an alvarezsaur, having three fingers of roughly equal length with the first one being robust |  |
| Baotianmansaurus[230] | - Xingliao Zhang - Junchang Lü - Li Xu - Jinhua Li - Li Yang - Weiyong Hu - Songhai Jia - Qiang Ji - Chengjun Zhang |
2009 | Gaogou Formation (Late Cretaceous, Cenomanian to Coniacian) |
China (Henan) |
Large but only known from a few bones |  |
| Baptornis[231] | - Othniel C. Marsh | 1877 | Niobrara Formation (Late Cretaceous, Coniacian to Campanian) |
United States ( Kansas) |
Possible remains are known from northern Europe |  |
| Barapasaurus[232] | - Sohan L. Jain - T. S. Kutty - T. Roy-Chowdhury - Sankar Chatterjee |
1975 | Kota Formation (Early Jurassic to Middle Jurassic, Pliensbachian to Callovian) |
India (Telangana) |
Several individuals have been found associated with tree trunks, which may represent the aftermath of a flood |  |
| Barbaridactylus[70] | - Nicholas R. Longrich - David M. Martill - Brian Andres |
2018 | Couche III (Late Cretaceous, Maastrichtian) |
Morocco (Béni Mellal-Khénifra) |
A very close relative or even species of Nyctosaurus |  |
| Barbosania[233] | - Ross A. Elgin - Eberhard Frey |
2011 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
Several specimens formerly assigned to Brasileodactylus may be assignable to this genus | |
| Barilium[234] | - David B. Norman | 2010 | Wadhurst Clay Formation (Early Cretaceous, Valanginian) |
England ( East Sussex) |
Robust with strong vertebrae with short neural spines |  |
| Barosaurus[235] | - Othniel C. Marsh | 1890 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( South Dakota* Utah) |
Similar to Diplodocus but larger and with a longer neck |  |
| Barrosasaurus[236] | - Leonardo Salgado - Rodolfo A. Coria |
2009 | Anacleto Formation (Late Cretaceous, Campanian) |
Argentina ( Neuquén) |
Only known from three vertebrae but are well-preserved enough to warrant recognition as a distinct genus |  |
| Barsboldia[237] | - Teresa Maryańska - Halszka Osmólska |
1981 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Possessed elongated neural spines that are tallest above the hips | .jpg) |
| Baryonyx[238] | - Alan J. Charig - Angela C. Milner |
1986 | Weald Clay (Early Cretaceous, Hauterivian to Barremian) |
England (  Surrey) |
One specimen was found with the remains of fish and a juvenile iguanodont in its stomach, suggesting it was a generalist predator |  |
| Bashanosaurus[239] | - Hui Dai - Ning Li - Susannah C.R. Maidment - Guangbiao Wei - Yuxuan Zhou - Xufeng Hu - Qingyu Ma - Xunqian Wang - Haiqian Hu - Guangzhao Peng |
2021 | Xiashaximiao Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
China (Chongqing) |
One of the most primitive stegosaurs, with a skeleton that combines traits of stegosaurs and more basal thyreophorans |  |
| Bashunosaurus[240] | - Xuewen Kuang | 2004 | Xiashaximiao Formation (Middle Jurassic to Late Jurassic, Bathonian to Oxfordian) |
China (Sichuan) |
Although described as a macronarian, this has yet to be rigorously tested |  |
| Batrachognathus[241] | - Anatoly N. Riabinin | 1948 | Karabastau Formation (Middle Jurassic to Late Jurassic, Callovian to Kimmeridgian) |
Kazakhstan (Jambyl) |
Had a U-shaped snout somewhat similar to those of frogs |  |
| Batyrosaurus[242] | - Pascal Godefroit - François Escuillié - Yuri L. Bolotsky - Pascaline Lauters |
2012 | Bostobe Formation (Late Cretaceous, Santonian to Campanian) |
Kazakhstan (Kyzylorda) |
Remains originally identified as Arstanosaurus |  |
| Baurutitan[243] | - Alexander W. A. Kellner - Diogenes A. Campos - Marcelo N. F. Trotta |
2005 | Serra da Galga Formation (Late Cretaceous, Maastrichtian) |
Brazil (  Minas Gerais) |
Originally described from an associated series of nineteen vertebrae, with new remains discovered later |  |
| Bauxitornis[244] | - Gareth J. Dyke - Attila Ősi |
2010 | Csehbánya Formation (Late Cretaceous, Santonian) |
Hungary ( Veszprém) |
Fragmentary but unique in the structure of its tarsometatarsus |  |
| Bayannurosaurus[245] | - Xing Xu - Qingwei Tan - Yilong Gao - Zhiqiang Bao - Zhigang Yin - Bin Guo - Junyou Wang - Lin Tan - Yuguang Zhang - Hai Xing |
2018 | Bayin-Gobi Formation (Early Cretaceous, Albian) |
China (Inner Mongolia) |
Known from a well-preserved, almost complete skeleton |  |
| Beg[246] | - Congyu Yu - Albert Prieto-Márquez - Tsogtbaatar Chinzorig - Zorigt Badamkhatan - Mark A. Norell |
2020 | Ulaanoosh Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
Mongolia ( Ömnögovi) |
Its skull has a rugose texture |  |
| Beibeilong[247] | - Hanyong Pu - Darla K. Zelenitsky - Junchang Lü - Philip J. Currie - Kenneth Carpenter - Li Xu - Eva B. Koppelhus - Songhai Jia - Le Xiao - Huali Chuang - Tianran Li - Martin Kundrát - Caizhi Shen |
2017 | Gaogou Formation (Late Cretaceous, Cenomanian to Coniacian) |
China (Henan) |
Known from only a single embryo still in its egg |  |
| Beiguornis[248] | - Xuri Wang - Shubin Ju - Wensheng Wu - Yichuan Liu - Zheng Guo - Qiang Ji |
2022 | Longjiang Formation (Early Cretaceous, Barremian to Aptian) |
China (Inner Mongolia) |
Had a short but robust manual ungual | |
| Beipiaognathus[249] | - Yuanchao Hu - Xuri Wang - Jiandong Huang |
2016 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
Described based on a chimeric holotype including compsognathid elements | |
| Beipiaopterus[250] | - Junchang Lü | 2003 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
Known from a single specimen with extensive soft tissue preservation |  |
| Beipiaosaurus[251] | - Xing Xu - Zhilu Tang - Xiaolin Wang |
1999 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
Preserves evidence of downy feathers as well as a secondary coat of simpler "elongated broad filamentous feathers" or EBFFs |  |
| Beishanlong[252] | - Peter J. Makovicky - Daqing Li - Keqin Gao - Matthew Lewin - Gregory M. Erickson - Mark A. Norell |
2010 | Xiagou Formation (Early Cretaceous, Aptian) |
China (Gansu) |
Lacked the elongated claws of more derived ornithomimosaurs |  |
| Bellubrunnus[253] | - David W. E. Hone - Helmut Tischlinger - Eberhard Frey - Martin Röper |
2012 | Torleite Formation (Late Jurassic, Kimmeridgian) |
Germany ( Bavaria) |
Its wingtips pointed forwards, which is probably an aerodynamic adaptation |  |
| Bellulornis[254] | - Min Wang - Zhonghe Zhou - Shuang Zhou |
2016 | Jiufotang Formation (Early Cretaceous, Aptian) |
China (Liaoning) |
Originally named Bellulia, but this was preoccupied by a moth | |
| Bellusaurus[255] | - Zhiming Dong | 1990 | Shishugou Formation (Middle Jurassic to Late Jurassic, Callovian to Oxfordian) |
China (Xinjiang) |
Known from a bone bed with the remains of seventeen juvenile specimens |  |
| Bennettazhia[256] | - Lev A. Nessov | 1991 | Hudspeth Formation (Early Cretaceous to Late Cretaceous, Albian to Cenomanian) |
United States (  Oregon) |
May have been a mollusc eater that lived in large rookeries like seagulls |  |
| Berberosaurus[257] | - Ronan Allain - Ronald S. Tykoski - Najat Aquesbi - Nour-Eddine Jalil - Michel Monbaron - Dale A. Russell - Philippe Taquet |
2007 | Azilal Formation (Early Jurassic, Toarcian) |
Morocco (Drâa-Tafilalet) |
One of the oldest known ceratosaurs |  |
| Bergamodactylus[161] | - Alexander W. A. Kellner | 2015 | Calcare di Zorzino (Late Triassic, Norian) |
 Italy(  Lombardy) |
Possibly synonymous with Carniadactylus |  |
| Berthasaura[258] | - Geovane A. de Souza - Marina B. Soares - Luiz C. Weinschütz - Everton Wilner - Ricardo T. Lopes - Olga M. O. de Araújo - Alexander W. A. Kellner |
2021 | Goio-Erê Formation (Early Cretaceous, Aptian to Albian) |
Brazil (  Paraná) |
Possessed a short, toothless beak as adults, indicating a herbivorous or omnivorous diet |  |
| Betasuchus[259] | - Friedrich von Huene | 1932 | Maastricht Formation (Late Cretaceous, Maastrichtian) |
 Netherlands(  Limburg) |
The first terrestrial vertebrate named from the Maastrichtian stage |  |
| Bicentenaria[260] | - Fernando E. Novas - Martín D. Ezcurra - Federico L. Agnolín - Diego Pol - Raúl Ortíz |
2012 | Candeleros Formation (Late Cretaceous, Cenomanian) |
Argentina ( Río Negro) |
Several individuals were preserved together, suggesting a gregarious lifestyle |  |
| Bienosaurus[261] | - Zhiming Dong | 2001 | Lufeng Formation (Early Jurassic, Sinemurian) |
China (Yunnan) |
Potentially synonymous with Tatisaurus |  |
| Bissektipelta[262] | - Jolyon C. Parish - Paul M. Barrett |
2004 | Bissekty Formation (Late Cretaceous, Turonian) |
Uzbekistan (Navoiy) |
Has been suggested to be a filter feeder |  |
| Bistahieversor[263] | - Thomas D. Carr - Thomas E. Williamson |
2010 | Fruitland Formation (Late Cretaceous, Campanian) 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[264] | - Sebastian G. Dalman - Steven E. Jasinski - Spencer G. Lucas |
2022 | Kirtland Formation (Late Cretaceous, Campanian) |
United States ( New Mexico) |
Preserves bite marks from a tyrannosaurid |  |
| Blasisaurus[265] | - Penélope Cruzado-Caballero - Xabier Pereda-Suberbiola - José Ignacio Ruiz-Omeñaca |
2010 | Arén Formation (Late Cretaceous, Campanian to Maastrichtian) |
Spain ( Aragon) |
Only known from a partial skull but can be distinguished from contemporary lambeosaurines |  |
| Blikanasaurus[266] | - Peter M. Galton - Jacques Van Heerden |
1985 | Lower Elliot Formation (Late Triassic, Norian) |
South Africa ( Eastern Cape) |
A "hyper-robust" form that niche partitioned with other sauropodomorphs from its locality |  |
| Bogolubovia[267] | - Lev A. Nessov - Alexander A. Yarkov |
1989 | Rybushka Formation (Late Cretaceous, Campanian) |
Russia (  Penza Oblast Saratov Oblast*) |
Once considered a species of Pteranodon | |
| Bohaiornis[268] | - Dongyu Hu - Li Li - Lianhai Hou - Xing Xu |
2011 | Jiufotang Formation (Early Cretaceous, Aptian) |
China (Liaoning) |
Originally considered to have been preserved with gastroliths, although later these were found to be mineral concretions |  |
| Bolong[269] | - Wenhao Wu - Pascal Godefroit - Dongyu Hu |
2010 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
Described from only a skull, with an almost complete skeleton described later |  |
| Boluochia[270] | - Zhonghe Zhou | 1995 | Jiufotang Formation (Early Cretaceous, Aptian) |
China (Liaoning) |
Originally mistakenly believed to have possessed a hooked beak | |
| Bonapartenykus[271] | - Federico L. Agnolín - Jaime E. Powell - Fernando E. Novas - Martin Kundrát |
2012 | Allen Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina ( Río Negro) |
Its holotype was preserved with two eggs that may have been within its oviducts when it died | .png) |
| Bonapartesaurus[272] | - Penélope Cruzado-Caballero - Jaime E. Powell |
2017 | Allen Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina ( Río Negro) |
Belongs to the Austrokritosauria, a clade of hadrosaurids endemic to South America |  |
| Bonatitan[273] | - Agustín G. Martinelli - Analía M. Forasiepi |
2004 | Allen Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina ( Río Negro) |
Analysis of its inner ear suggests a decreased range of head movements compared to other sauropods |  |
| Bonitasaura[274] | - Sebastián Apesteguía | 2004 | Bajo de la Carpa Formation (Late Cretaceous, Santonian) |
Argentina ( Río Negro) |
The proportions of its body were somewhat similar to those of diplodocoids, likely through convergent evolution |  |
| Borealopelta[275] | - Caleb M. Brown - Donald M. Henderson - Jakob Vinther - Ian Fletcher - Ainara Sistiaga - Jorsua Herrera - Roger E. Summons |
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 |  |
| Borealosaurus[276] | - Hailu You - Qiang Ji - Matthew C. Lamanna - Jinglu Li - Yinxian Li |
2004 | Sunjiawan Formation (Late Cretaceous, Cenomanian) |
China (Liaoning) |
Its caudal vertebrae were distinctively opisthocoelous |  |
| Boreonykus[277] | - Phil R. Bell - Philip J. Currie |
2016 | Wapiti Formation (Late Cretaceous, Campanian to Maastrichtian) |
Canada ( Alberta) |
One of the few dromaeosaurids known from high latitudes |  |
| Boreopterus[278] | - Junchang Lü - Ji Qiang |
2005 | Yixian Formation (Early Cretaceous, Barremian) |
China (Liaoning) |
May have foraged while swimming using its large interlocking teeth to trap fish |  |
| Borogovia[279] | - Halszka Osmolska | 1987 | Nemegt Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Had a uniquely straight, flattened sickle claw, which may have had a weight-bearing function |  |
| Bothriospondylus[280] | - Richard Owen | 1875 | Kimmeridge Clay (Late Jurassic, Kimmeridgian) |
England (  Wiltshire) |
Several specimens have been assigned to this genus, but most of them have been reclassified into different genera |  |
| Brachiosaurus[281] | - Elmer S. Riggs | 1903 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Colorado* Oklahoma Utah Wyoming) |
A high browser with a tall chest and elongated forelimbs |  |
| Brachyceratops[282] | - Charles W. Gilmore | 1914 | Two Medicine Formation (Late Cretaceous, Campanian) |
United States ( Montana) |
Only known from juvenile remains, with one subadult since proven to belong to Styracosaurus |  |
| Brachylophosaurus[283] | - Charles M. Sternberg | 1953 | Judith River Formation (Late Cretaceous, Campanian) Oldman Formation (Late Cretaceous, Campanian)* |
Canada ( Alberta*) United States( Montana) |
Several specimens preserve extensive soft tissue remains |  |
| Brachypodosaurus[284] | - Dhirendra K. Chakravarti | 1934 | Lameta Formation (Late Cretaceous, Maastrichtian) |
India (Madhya Pradesh) |
Has been suggested to be a thyreophoran, but such an identification is unlikely | |
| Brachytrachelopan[285] | - Oliver W. M. Rauhut - Kristian Remes - Regina Fechner - Gerardo Cladera - Pablo F. Puerta |
2005 | Cañadón Calcáreo Formation (Late Jurassic, Oxfordian to Tithonian) |
Argentina ( Chubut) |
Possessed the shortest neck of any known sauropod |  |
| Bradycneme[286] | - Colin J. O. Harrison - Cyril A. Walker |
1975 | Sânpetru Formation (Late Cretaceous, Maastrichtian) |
Romania (Hunedoara) |
Potentially an alvarezsaurid |  |
| Brasileodactylus[287] | - Alexander W. A. Kellner | 1984 | Romualdo Formation (Early Cretaceous, Albian) |
Brazil ( Ceará) |
May not have had crests on the snout, unlike most similar pterosaurs | |
| Brasilotitan[288] | - Elaine B. Machado - Leonardo S. Avilla - William R. Nava - Diogenes A. Campos - Alexander W. A. Kellner |
2013 | Adamantina Formation (Late Cretaceous, Maastrichtian) |
Brazil ( São Paulo) |
Had an L-shaped dentary similar to that of Antarctosaurus and Bonitasaura |  |
| Bravasaurus[289] | - E. Martín Hechenleitner - Léa Leuzinger - Agustín G. Martinelli - Sebastián Rocher - Lucas E. Fiorelli - Jeremías R. A. Taborda - Leonardo Salgado |
2020 | Ciénaga del Río Huaco Formation (Late Cretaceous, Campanian to Maastrichtian) |
Argentina (  La Rioja) |
Discovered close to a large concentration of titanosaur eggs |  |
| Bravoceratops[290] | - Steven L. Wick - Thomas M. Lehman |
2013 | Javelina Formation (Late Cretaceous, Maastrichtian) |
United States ( Texas) |
Suggested to have had a single small horn on the top of its frill but this may be inaccurate |  |
| Breviceratops[291] | - Sergei M. Kurzanov | 1990 | Baruungoyot Formation (Late Cretaceous, Maastrichtian) |
Mongolia ( Ömnögovi) |
Only known from juvenile remains but can be distinguished from other protoceratopsids |  |
| Brevidentavis[292] | - Jingmai K. O'Connor - Thomas A. Stidham - Jerald D. Harris - Matthew C. Lamanna - Alida M. Bailleul - Han Hu - Min Wang - Hailu You |
2022 | Xiagou Formation (Early Cretaceous, Aptian) |
China (Gansu) |
May be an early hesperornithean based on characters of the teeth | |
| Brevirostruavis[293] | - Zhiheng Li - Min Wang - Thomas A. Stidham - Zhonghe Zhou - Julia A. Clarke |
2022 | Jiufotang Formation (Early Cretaceous, Aptian) |
China (Liaoning) |
Possessed an enlarged hyoid that suggests a feeding specialization similar to hummingbirds, honeyeaters, or woodpeckers |  |
| Brighstoneus[294] | - Jeremy A. F. Lockwood - David M. Martill - Susannah C.R. Maidment |
2021 | Wessex Formation (Early Cretaceous, Barremian) |
England ( Isle of Wight) |
Had a long snout tipped with a low bump |  |
| Brodavis[295] | - Larry D. Martin - Evgeny N. Kurochkin - Tim T. Tokaryk |
2012 | Frenchman Formation (Late Cretaceous, Maastrichtian)* Hell Creek Formation (Late Cretaceous, Maastrichtian) Nemegt Formation (Late Cretaceous, Maastrichtian) |
Canada ( Saskatchewan*) Mongolia( Ömnögovi) United States( South Dakota) |
Unlike most hesperornitheans, it lived in freshwater and was probably capable of flight |  |
| Brohisaurus[296] | - M. Sadiq Malkani | 2003 | Sembar Formation (Late Jurassic, Kimmeridgian) |
 Pakistan(  Balochistan) |
Originally thought to be a sauropod, but several osteoderms potentially referrable to the genus suggest it may have actually been an ankylosaur | |
| Brontomerus[297] | - Michael P. Taylor - Mathew J. Wedel - Richard L. Cifelli |
2011 | Cedar Mountain Formation (Early Cretaceous, Aptian) |
United States ( Utah) |
Possessed an enlarged ilium which supported powerful leg muscles, which it may have used to kick away predators |  |
| Brontosaurus[298] | - Othniel C. Marsh | 1879 | Morrison Formation (Late Jurassic, Kimmeridgian to Tithonian) |
United States ( Utah Wyoming*) |
Popularly associated with Apatosaurus but a study of diplodocids found enough differences for it to be classified as a separate genus |  |
| Bruhathkayosaurus[299] | - P. M. Yadagiri - Krishnan Ayyasami |
1987 | Kallamedu Formation (Late Cretaceous, Maastrichtian) |
India (Tamil Nadu) |
Reportedly exceptionally large, with its lost fossils having been informally speculated to be misidentified tree trunks before later research suggested at least the tibia is real |  |
| Buitreraptor[300] | - Peter J. Makovicky - Sebastián Apesteguía - Federico L. Agnolín |
2005 | Candeleros Formation (Late Cretaceous, Cenomanian) |
Argentina ( Río Negro) |
May have been a pursuit predator due to its long legs |  |
| Burianosaurus[301] | - Daniel Madzia - Clint A. Boyd - Martin Mazuch |
2018 | Peruc–Korycany Formation (Late Cretaceous, Cenomanian) |
 Czech Republic(  Central Bohemia) |
May be closely allied to the rhabdodontids |  |
| Buriolestes[302] | - Sergio F. Cabreira - Alexander W. A. Kellner - Sérgio Dias-da-Silva - Lúcio R. da Silva - Mario Bronzati - Júlio C. A. Marsola - Rodrigo T. Müller - Jonathas S. Bittencourt - Brunna J. Batista - Tiago Raugust - Rodrigo Carrilho - André Brodt - Max C. Langer |
2016 | Candelária Sequence (Late Triassic, Carnian) |
Brazil ( Rio Grande do Sul) |
Unlike all other sauropodomorphs, it was completely carnivorous, with serrated teeth to match |  |
| Bustingorrytitan[303] | - María Edith Simón - Leonardo J. Salgado |
2023 | Huincul Formation (Late Cretaceous, Cenomanian) |
Argentina ( Neuquén) |
Large yet distantly related to other gigantic titanosaurs |  |
| Byronosaurus[304] | - Mark A. Norell - Peter J. Makovicky - James M. Clark |
2000 | Djadokhta Formation (Late Cretaceous, Campanian) |
Mongolia ( Ömnögovi) |
Two juvenile skulls were found in an oviraptorid nest and claimed to be evidence of nest parasitism in this taxon, but both their identity and taphonomy have been questioned |  |