Nuoerosaurus Chaganensis Mount

This list of informally named dinosaurs is a listing of dinosaurs (excluding Aves; birds and their extinct relatives) that have never been given formally published scientific names. This list only includes names that were not properly published ("unavailable names") and have not since been published under a valid name (see list of dinosaur genera for valid names). The following types of names are present on this list:

* ''Nomen nudum'', Latin for "naked name": A name that has appeared in print but has not yet been formally published by the standards of the International Commission on Zoological Nomenclature. ''Nomina nuda'' (the plural form) are invalid, and are therefore not italicized as a proper generic name would be.
* ''Nomen manuscriptum'', Latin for "manuscript name": A name that appears in manuscript but was not formally published. A ''nomen manuscriptum'' is equivalent to a ''nomen nudum'' for everything except the method of publication, and description.
* ''Nomen ex dissertationae'', Latin for "dissertation name": A name that appears in a dissertation but was not formally published.
* Nicknames or descriptive names given to specimens or taxa by researchers or the press.

A

Alamotyrannus

"Alamotyrannus" ("Ojo Alamo tyrant") is the informal name given to an as yet undescribed genus of tyrannosaurid from the Late Cretaceous period of North America. The fossils of this animal originate from the Ojo Alamo Formation in New Mexico and they were discovered during the Early 2000s (discovered by anonymous). It may be either a distinct genus or just a synonym of '' Tyrannosaurus''. The suggested binomial "Alamotyrannus brinkmani", was created when the paper describing the genus was written in 2013. "Alamotyrannus" lived during the Campanian, around 70 million years ago, which was two million years before the first '' Tyrannosaurus'' existed.

Alan the Dinosaur

"Alan the Dinosaur" is the name given to a sauropod caudal vertebra (YORYM:2001.9337) found in the Saltwick Formation (Middle Jurassic, Aalenian) of Whitby, England. It is the oldest sauropod found in the United Kingdom, dating back 176-172 million years ago. It gained the nickname after Alan Gurr, who found it in 1995 and because it is not identifiable to species level. An analysis done in 2015 found that it was a member of Eusauropoda, could be excluded from Diplodocoidea, and was most similar to '' Cetiosaurus''.

The fossil of "Alan" is housed in the Yorkshire Museum, where it forms part of the Yorkshire's Jurassic World exhibit, featuring a VR recreation.

Allosaurus robustus

"Allosaurus robustus" is an informal name used for specimen "NMV P150070", a theropod astragalus known from the Wonthaggi Formation (Early Cretaceous) of Victoria, Australia. When first studied, it was thought to have belonged to a species of '' Allosaurus''. Samuel Welles challenged this identification as he thought that the astragalus belonged to an ornithomimid, but the original authors defended their classification. Sometime in the early 2000s, Daniel Chure examined the bone and found that it did not represent a new species of ''Allosaurus'', but could still represent an allosauroid. At the same time, Yoichi Azuma and Phil Currie noted that the astragalus resembled that of their new genus '' Fukuiraptor''. It may well represent an theropod related to or the same as '' Australovenator'', though some argue that it could represent an abelisauroid. A 2019 study strongly supported a megaraptoran affinity for the astragalus.

The name "Allosaurus robustus", first confined as a museum label, was first published by Chure in 2000.

Amargastegos

"Amargastegos" is an informal genus of extinct stegosaurid ornithischian dinosaur known from the La Amarga Formation of Argentina, named by Roman Ulansky in 2014 on the basis of MACN N-43 (some dorsal osteoderms, the cervical and caudal vertebrae, and one skull bone). In 2016, Peter Malcolm Galton and Kenneth Carpenter declared it a ''nomen nudum'', establishing it as an indeterminate stegosaur.

Amphicoelias brontodiplodocus/Barackosaurus

"Barackosaurus" is the informal name created in 2010 which is used for a sauropod found in Kimmeridgian-aged sediments pertaining to the Morrison Formation, Wyoming. It was found in the Dana Quarry and "Barackosaurus" was supposedly 20 meters long and weighed 20 tons. In 2010, an article was made available, but not formally published, by Henry Galiano and Raimund Albersdorfer in which they dubbed the Dana Quarry specimens which had already been referred to as "Barackosaurus" as "Amphicoelias brontodiplodocus". The specific name referred to their hypothesis based on these specimens that nearly all Morrison diplodocid species are either growth stages or represent sexual dimorphism among members of the genus ''Amphicoelias'', but this analysis was met with skepticism and the publication itself has been disclaimed by its lead author, explaining that it is "obviously a drafted manuscript complete with typos, etc., and not a final paper. In fact, no printing or distribution has been attempted". As of 2015, they are now on display at the Lee Kong Chian Natural History Museum in Singapore.

Andhrasaurus

"Andhrasaurus indicus" is an informal genus of extinct armored ornithischian dinosaur from the Kota Formation of India. Ulansky (2014) coined the name for skull elements, about 30 osteoderms, and the extremities of vertebrae and limbs, all preserved in the collections of the GSI and assigned to Ankylosauria by Nath et al. (2002). In 2016, Peter Malcolm Galton and Kenneth Carpenter noted that "Andhrasaurus" did not meet ICZN requirements and therefore declared it a ''nomen nudum'', listing it as Thyreophora indet., while noting that the jawbones described by Nath et al. (2002) belonging to crocodylomorphs.Galton, Peter M. & Carpenter, Kenneth, 2016, "The plated dinosaur ''Stegosaurus longispinus'' Gilmore, 1914 (Dinosauria: Ornithischia; Upper Jurassic, western U.S.), type species of ''Alcovasaurus'' n. gen.", ''Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen'' 279(2): 185–208 The dermal armor informally named "Andhrasaurus" was redescribed by Galton (2019).

Angeac ornithomimosaur

The "Angeac ornithomimosaur" is an informal name given to an unnamed ornithomimosaur taxon known from the Early Cretaceous (previously thought to be Hauterivian- Barremian in age, but now thought to be Berriasian agedRonan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.
Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary
Geodiversitas, Museum National d’Histoire Naturelle Paris, In press. ffhal-03264773f) Angeac-Charente bonebed (part of the stratigraphy of the Aquitaine Basin) near Angeac-Charente in western France. The taxon is toothless and is known from numerous disarticulated remains representing at least 70 individuals covering almost all of the skeleton, some remains were described by Allain ''et al.'' (2014).

Angloposeidon

"Angloposeidon" is the informal name given to a sauropod dinosaur from the Early Cretaceous ( Barremian) Wessex Formation of the Isle of Wight in southern England. It was a possible brachiosaurid but has not been formally named. Darren Naish, a notable vertebrate palaeontologist, has worked with the specimen and has recommended that this name only be used informally and that it not be published. However, he published it himself in his book ''Tetrapod Zoology Book One'' from 2010. The remains consist of a single cervical vertebra (MIWG.7306), which indicate it was a very large animal, 20 metres or greater in length.

Archaeoraptor

"Archaeoraptor" is the informal generic name for an important fossil from China that was later discovered to have been fabricated from multiple unrelated fossils. The name was created in an article published in ''National Geographic'' magazine in 1999, where the magazine claimed that the fossil was a " missing link" between birds and terrestrial theropod dinosaurs. Even prior to this publication there had been severe doubts about the fossil's authenticity. Further scientific study showed it to be a forgery constructed from rearranged pieces of real fossils from different species. Zhou ''et al.'' found that the head and upper body actually belong to a specimen of the primitive fossil bird '' Yanornis'', and another 2002 study found that the tail belongs to a small winged dromaeosaur, '' Microraptor'', named in 2000. The legs and feet belong to an as yet unknown animal.

Archbishop

"The Archbishop" is a giant brachiosaurid sauropod dinosaur similar to '' Brachiosaurus'' and '' Giraffatitan''. It was long considered a specimen of ''Brachiosaurus'' (now ''Giraffatitan'') ''brancai'' due to being found in the same formation in Tendaguru, Tanzania. However, the "Archbishop" shows significant differences including a unique vertebral morphology and a proportionally longer neck, that indicates it is a different, previously unknown genus and species. It was discovered by Frederick Migeod in 1930. "The Archbishop" is a nickname that functions as a placeholder – the specimen currently has no scientific name. The specimen is currently housed in the Natural History Museum in London, and will eventually be re-described by Dr. Michael P. Taylor of Bristol University. In May 2018, Taylor started to work on describing the Archbishop.

Atlantohadros

"Atlantohadros", more commonly known as the "Merchantville hadrosaur", is an informally named hadosaurid dinosaur that lived in the Merchantville Formation in the northeastern United States. Brown (2021) found "Atlantohadros" to be more derived than '' Tethyshadros'' but less derived than Saurolophinae and Lambeosaurinae. The name was intended to be used in that publication, but was cut for unknown reasons; initial versions of Brown (2021) contained the word "Atlantohadros" superimposed over "Merchantville Taxon" in a cladogram; subsequent corrections have erased the genus name entirely.

Three specimens were discovered northwest of Freehold near Manalapan–Marlboro township line in Monmouth County during the 1970s. These are: YPM VPPU.021813, YPM VPPU.021813, and AMNH 13704YPM VPPU.021813, possibly belonging to the same individual as YPM VPPU.021813 due similar weathering, size and the same horizon. These specimens consist of both coracoids, both scapulae, a femur, a fragmentary proximal tibia, and a dentary from a cast of the specimen (the original likely lost in YPM's catalogue) in the adult specimen, as well as a rib, a femur and long bone portions in the juvenile. AMNH 13704, id a partial dentary of a probable perinate. Scattered bones associated with these include a quadrate, several partial maxilla portions, a partial jugal, skull roof fragments and several rib fragments.

B

Balochisaurus

"Balochisaurus" (meaning "Balochi lizard", for the Baloch tribes of Pakistan) is an informal taxon of titanosaurian sauropod dinosaur from the Late Cretaceous of Pakistan. The proposed species is "B. malkani". The discovery was made (along with other dinosaur specimens) near Vitariki by a team of paleontologists from the Geological Survey of Pakistan. Described in 2006 by M.S. Malkani, the genus is based on seven tail vertebrae found in the Maastrichtian-age Vitakri Member of the Pab Formation, with additional vertebrae and a partial skull assigned to it. ''Balochisaurus'' was assigned to the family "Balochisauridae" along with " Marisaurus", although the family was used as a synonym of older Saltasauridae.

Barnes High Sauropod

The "Barnes High sauropod" is the informal name given to MIWG-BP001, an undescribed sauropod dinosaur specimen from the Wessex Formation on the Isle of Wight. It was discovered in the cliffs around Barnes High in 1992 and is currently owned by the privately run unaccredited Dinosaur Farm Museum near Brighstone, the ownership situation was described as "complex" and the specimen is currently inaccessible to researchers. It is roughly 40% complete and consists of a "Partial postcranial skeleton, including presacral vertebrae, anterior caudal vertebrae, girdle and limb elements" including a largely complete forelimb. It has been suggested to be a Brachiosaur and is possibly synonymous with the earlier named '' Eucamerotus'' due to similarities with the vertebrae.

Bayosaurus

"Bayosaurus" is the informal name given to an as yet undescribed genus of dinosaur. The name was coined by paleontologists Rodolfo Coria, Philip J. Currie, and Paulina Carabajal in 2006. It apparently was an abelisauroid from the Turonian Cerro Lisandro Formation of Neuquén, Argentina, around long. The specimen is MCF-PVPH-237, including dorsal and sacral vertebrae, a fragmentary pelvis, and other partial bones, which were discovered in 2000. The name was used in a phylogenetic analysis to indicate the position of MCF-PVPH-237.

Beelemodon

"Beelemodon" is the informal name given to an undescribed theropod genus from the Late Jurassic, possibly belonging to a coelurosaur. The fossils include two teeth found in Wyoming, United States. The name appeared in print in 1997, when paleontologist Robert T. Bakker mentioned it in a symposium for the Academy of Natural Sciences.Bakker, R. ''Raptor family values: Allosaur parents brought great carcasses into their lair to feed their young.'' In "Dinofest International", Proceedings of a Symposium, Academy of Natural Sciences, eds Wolberg, Sump and Rosenberg, 51 – 63 (1997). The teeth are most similar to '' Compsognathus'', but have no unique features and also share similarities with '' Protarchaeopteryx'' and dromaeosaurids.

Biconcavoposeidon

"Biconcavoposeidon" is the placeholder name for AMNH FARB 291, five consecutive posterior dorsal vertebrae of a brachiosaurid sauropod, from the Late Jurassic Morrison Formation, Wyoming. Not much else is currently known about "Biconcaveoposeidon", except that it was discovered in the Bone Cabin quarry in 1898.

Bihariosaurus

"Bihariosaurus" (meaning "Bihor lizard") is an invalid genus of iguanodontian dinosaur from Early Cretaceous Bauxite of Cornet, Romania. The type species, "Bihariosaurus bauxiticus", was named but not described by Marinescu in 1989. It was similar to '' Camptosaurus'', and was an iguanodont. The original publication of the taxon did not include sufficient description, and the illustrations cannot distinguish it from any other ornithopod.

Biscoveosaurus

"Biscoveosaurus" is the informal name of an ornithopod dinosaur specimen from the Early Maastrichtian age Snow Hill Island Formation of James Ross Island, Antarctica. It comes from the Cape Lamb Member of the formation, the same member as '' Morrosaurus'', another basal ornithopod. As such, it's been suggested it may be a secondary specimen of that species, but as the holotype of ''Morrosaurus'' is fragmentary and doesn't overlap with the material of "Biscoveosaurus", this can't as yet be tested. The specimen consists of dentaries, teeth, a braincase, parts of the maxillae, forelimb elements, assorted vertebrae, and the pectoral girdle; this makes it unique compared to the other James Ross Island ornithopods, which do not have both cranial and postcranial remains. It has been estimated the animal would've been about in length.

C

Capitalsaurus

"Capitalsaurus" is the informal genus name given to the species formerly known as ''Creosaurus potens'' and '' Dryptosaurus potens''. The only known specimen was discovered in a layer of the Arundel Formation in Washington, D.C. It was a theropod, and it lived during the Cretaceous. It is a nomen nudum, the name having never been formally published. "Capitalsaurus" was discovered in January 1898 at the intersection of First and F Streets S.E., in the District of Columbia – an intersection now designated as Capitalsaurus Court. It was not uncovered by any paleontological activity, but as a by-product of sewer work. The only known specimen of "Capitalsaurus" consists of part of a single vertebra. Some paleontologists feel that this is insufficient justification for a name that suggests an entire genus, and that "Capitalsaurus" is merely an indeterminate theropod. Others note that this is hardly the only dinosaur with a common name that does not helpfully reflect its taxonomy. The "Capitalsaurus" is the official dinosaur of the District of Columbia.

Changdusaurus

"Changdusaurus" (also known as "Changtusaurus") is the informal name given to a genus of dinosaur from the Late Jurassic Period. It lived in what is now China. "Changdusaurus" is classified as a stegosaurid. The type species was named "Changdusaurus laminoplacodus" by Zhao in 1986, but it has never been formally described, and remains a ''nomen nudum''. One source indicates the fossils have been lost.

Comanchesaurus

"Comanchesaurus" is a ''nomen ex dissertationae'' for fossilized remains from the Late Triassic of New Mexico that were initially interpreted as belonging to a theropod dinosaur. The remains, NMMNH P-4569, consist of a partial skeleton including vertebral centra and hindlimb bones, and came from the Norian-age Upper Triassic Bull Canyon Formation of Guadalupe County. Adrian Hunt, in his unpublished dissertation, proposed the name "Comanchesaurus kuesi" for the specimen, but the name was never adopted, and was first referred to in the scientific literature in a 2007 redescription of Late Triassic North American material thought to belong to dinosaurs (Nesbitt, Irmis, and Parker, 2007). In the redescription, the authors found the material to belong to a "possible indeterminate saurischian".

Cryptotyrannus

"Cryptotyrannus" (meaning "secret/hidden tyrant"), more commonly known as the "Merchantville tyrannosauroid", is an informally named tyrannosauroid dinosaur that lived in the Merchantville Formation. It was informally named by Brown (2021), who found it to be the sister taxon of '' Dryptosaurus'', reinstating Dryptosauridae. The name appeared in the initial version of Brown's paper, superimposed over "Merchantville Taxon" in a cladogram; a subsequent correction has erased the name entirely.

"Cryptotyrannus" is known from two specimens discovered during the 1970s, the holotype YPM VPPU.021795 and the paratype YPM VPPU.022416. Similar coloration and weathering indicate that these are probably the same individual. These are a partial foot bone and one caudal vertebrae. However, a skeletal produced for the paper depicts a hand claw. The foot morphology is consistent with Tyrannosaurs, being extremely similar to the ''Dryptosaurus aquilunguis''. Autapomorphies include a metatarsal IV that is far more gracile and IV in proximal view also has a triangular, rather than subrectangular in outline. The holotype was once tentatively assigned to '' "Coelosaurus" antiquus''.

Shark bites present on the holotype suggest that the specimen's fragmentary nature is due to predation or scavenging by marine predators.

D

Dachongosaurus

"Dachongosaurus" is the informal name given to an undescribed genus of sauropod dinosaur from the Early Jurassic of China. It is known from fossils including at least a partial articulated skeleton from the Dark Red Beds of the Lower Lufeng Series ( Sinemurian stage) in Yunnan.Zhao, 1985. The reptilian fauna of the Jurassic in China. Pages 286–289, 347 in Wang, Cheng and Wang (eds.). The Jurassic System of China. Geological Publishing House, Beijing. Possibly a cetiosaur, the " type species" is "Dachongosaurus yunnanensis", coined by Zhao in 1985. An alternate spelling is "Dachungosaurus". As with other informal names coined by Zhao in 1985 and 1983, nothing has since been published, and the remains may have been redescribed under another name.

Damalasaurus

"Damalasaurus" (meaning "Damala lizard") is the informal name given to a genus of herbivorous dinosaur from the Early Jurassic. It was a sauropod, though its exact classification within the clade is unknown. Fossils of "Damalasaurus", including a rib, have been found in the Middle Daye Group of Tibet. Species attributed to this genus include "Damalasaurus laticostalis" and "D. magnus", although it is possible that both names refer to the same species.

Duranteceratops

"Duranteceratops" is a purported new taxon of chasmosaurine ceratopsid from the Hell Creek Formation. In 2012, a ceratopsid skull reportedly distinguishable from '' Triceratops'' was unearthed in South Dakota by a fossil poacher named John Carter. Though it has yet to be published, according to the ''Prehistoric Times'' issue no. 121 from Spring 2017, the specimen is to be named "Duranteceratops".

E

EK troodontid

The "EK troodontid" (specimen SPS 100/44) is an unnamed genus of troodontid dinosaur discovered in Mongolia. In the scientific literature it is referred to as the "EK troodontid", after the Early Cretaceous sediments in which it was found. SPS 100/44 was discovered by Sergei Mikhailovich Kurzanov during the 1979 Soviet-Mongolian Paleontological Expedition. It was found in deposits of the Barunbayaskaya Svita at the Khamareen Us locality, Dornogov (southeastern Gobi Desert), in the Mongolian People's Republic. SPS 100/44 was described by Rinchen Barsbold and colleagues in 1987.Barsbold, Rhinchen, Osmolska, Halszka, Kurzanov, Sergei Mikhailovich. (1987). "On a new troodontid (Dinosauria. Theropoda) from the Early Cretaceous of Mongolia". ''Acta Palaeontologica Polonica'' 32(1–2): 121–132

Its fossil remains include an incomplete skeleton consisting of the braincase, posterior parts of the lower mandibles, a maxillary fragment with teeth, parts of five cervical vertebrae (cervicals ?2-?6), an articulated right manus with partial semilunate, left manus phalanx I-1, distal end of the left femur, and fragmentary left and right pedes. Barsbold pointed out that the specimen was smaller and from older sediments than other known troodontids, but it had some features of the skull that could have made it a juvenile. Barsbold also indicated the high degree of fusion of the bones of the skull and the unusual foot morphology to indicate that it might be an adult of an unknown taxon. Barsbold took the conservative position and did not name this specimen because it was not complete enough to rule out the possibility that it was a juvenile of a known genus of troodontid. Barsbold also noted that the naturally articulated manus of SPS 100/44 showed no signs of an opposable third digit, as was suggested for '' Troodon'' by Russell and Seguin in 1982. Turner and colleagues, in 2007, found the EK troodontid to be a distinct basal genus of troodontid, in a polytomy with '' Jinfengopteryx'' and a clade of more derived troodontids.

Eoplophysis

"Eoplophysis" is a genus of stegosaur known from the Middle Jurassic Cornbrash Formation, Sharp's Hill Formation, and Chipping Norton Formation of England. It was originally named ''Omosaurus vetustus'' by the renowned German paleontologist Friedrich von Huene. The holotype, OUM J.14000, is a right femur of a juvenile individual from the Middle Jurassic (upper Bathonian) Cornbrash Formation of Oxfordshire, England, although it was probably reworked from the slightly older Forest Marble Formation in view of its eroded nature. Because of the renaming of ''Omosaurus'', an occupied name, as ''Dacentrurus'', ''O. vetustus'' was renamed into a ''Dacentrurus vetustus'' in 1964. In the 1980s, researcher Peter Malcolm Galton reviewed all known stegosaur material from the Bathonian of England and concluded that ''Omosaurus vetustus'' was valid and should be tentatively referred to ''Lexovisaurus''. However, the species was later considered a ''nomen dubium'' in both reviews of Stegosauria. In their alpha-taxonomic review of stegosaurs, Susannah Maidment and her colleagues noted that OUM J.14000 shares characters present in both sauropods and stegosaurs, but that it lacks synapomorphies exclusive to Stegosauria and assigned it as a Dinosauria indet. Nevertheless, the amateur paleontologist Roman Ulansky coined the new genus "Eoplophysis" ("Dawn Armed Form") for ''O. vetustus'', noting differences with the femora of other stegosaurs.

Eugongbusaurus

"Eugongbusaurus" is the informal name (''nomen nudum'') proposed for a neornithischian found in the Oxfordian-age Shishugou Formation of Xinjiang, China. The intended type species, ''"Gongbusaurus" wucaiwanensis'', was described by Dong Zhiming in 1989 for two partial skeletons as a second species of the poorly known tooth taxon ''Gongbusaurus''. Fragmentary skeleton IVPP 8302, the type specimen for the new species, included a partial lower jaw, three tail vertebrae, and a partial forelimb. Second specimen IVPP 8303 consisted of two hip vertebrae, eight tail vertebrae, and two complete hind limbs. Dong estimated it as around long, and considered it to be a strong runner. He assigned the genus ''Gongbusaurus'' to the Hypsilophodontidae, a paraphyletic grade of small herbivorous bipedal dinosaurs. Because dinosaur teeth are generally not distinctive enough to hold a name, it is unsurprising that other paleontologists have suggested removing "G." ''wucaiwanensis'' from ''Gongbusaurus'' and giving it its own genus. The possible replacement name "Eugongbusaurus" leaked out accidentally and remains informal.

F

Fendusaurus

"Fendusaurus" is a ''nomen ex dissertatione'' proposed by Fedak (2006) for FGM 998GF13-II, which includes a skull. Other specimens referred to "Fendusaurus" are FGM998GF13-I, FGM998GF13-III, FGM998GF69, FGM998GF9, and FGM998GF18, all found by a crew from the Princeton University. All the specimens include femora and coracoids, and although they each share slightly different features, the differences are credited to intra-specific variation. Known specimens of "Fendusaurus" were previously classified as cf. ''Ammosaurus''. The femora and coracoids also help identify different individuals, and Timothy J. Fedak, the described of the specimens, found that each block represented about one individual. "Fendusaurus" is known from the Early Jurassic (Hettangian) McCoy Brook Formation of Wasson Bluff, Nova Scotia. It is the first non-avian dinosaur from Nova Scotia. As five specimens of "Fendusaurus" are from the McCoy Brook Formation, the formation is the richest prosauropod site in North America. The formation is also similar to other formations of North America and Asia, as it lacks any remains presently assigned to ''Anchisaurus''. Fedak places "Fendusaurus" as a genus of the family Massospondylidae.Fedak TJ. Description and evolutionary significance of the sauropodomorph dinosaurs from the Early Jurassic (Hettangian) McCoy Brook Formation. Ph.D. Dissertation, Dalhousie University. 2006.

The specimens of "Fendusaurus" include mostly crushed vertebrae, along with appendicular elements. They are distinguishable from ''Anchisaurus'' by the morphology of both the ilium and sacral vertebrae. However, in some specimens, the morphology of the femora and coracoids are quite different, which led Fedak to speculate that more than one species may have been present. "Fendusaurus", according to Fedak, can be distinguished from all closely related sauropodomorphs by the extreme elongation of the cervical vertebrae; a four vertebrae sacrum that includes a dorsosacral and caudosacral; the elongate postacetabular process of the ilium; and an expanded anterior distal process of the tibia.

Ferganastegos

"Ferganastegos" is a dubious genus of stegosaur from the Middle Jurassic ( Callovian) Balabansai Formation of Fergana Valley, Kyrgyzstan.Ulansky, R. E., (2014). Evolution of the stegosaurs (Dinosauria; Ornithischia). Dinologia, 35 pp. n Russian OWNLOAD PDFttp://dinoweb.narod.ru/Ulansky_2014_Stegosaurs_evolution.pdf. The holotype of "Ferganastegos callovicus", IGB 001, consists of four posterior dorsal vertebrae. Although Averianov et al. did not consider the vertebrae diagnostic to genus, the freelance Russian dinosaur enthusiast and amateur paleontologist Roman Ulansky decided that the differences between IGB 001 and other stegosaurs were sufficient to warrant a binomial for IGB 001, "Ferganastegos callovicus" (Callovian roof from Fergana Valley), despite the fact he did not examine the material himself. Other researchers still contend that the material is not diagnostic and that the genus is a nomen dubium.

Ferropectis

"Ferropectis" is a nodosaurid ankylosaur from the Late Cretaceous (Cenomanian) Eagle Ford Group in Texas that was named in a 2018 dissertation by Matt Clemens. The intended type species is "Ferropectis brysorum", and in the phylogenetic analysis it was placed as the sister taxon to '' Borealopelta'' in a clade including ''Hungarosaurus'', '' Europelta'', and ''Pawpawsaurus''.

Futabasaurus

"Futabasaurus" is an informal name for a genus of theropod dinosaur from the Late Cretaceous of Japan, known only from a partial shin bone of ~ wide that was discovered in the Coniacian-age Ashizawa Formation of the Futaba Group; it was likely around when fully grown. It was first mentioned as "Futaba-ryu" by Hasegawa ''et al.'' (1987), and the name was coined by David Lambert in 1990 as a conversion from the Japanese nickname "Futaba-ryu", for an undescribed theropod. Dong Zhiming and coauthors briefly discussed the fossil shin bone it was based on that same year, publishing a photograph. They considered the bone to belong to an indeterminate tyrannosaurid. If the specimen is eventually described and named, it will require a different name, because the name ''Futabasaurus'' has since been used for a genus of plesiosaur.

G

Gadolosaurus

"Gadolosaurus" is an informal name given to PIN, no. 3458/5 an unnamed juvenile hadrosauroid dinosaur specimen from the Bayan Shireh Formation of Baishan Tsav, Mongolia. The name "Gadolosaurus" was first used in a 1979 book by Japanese paleontologist Tsunemasa Saito, in a caption for a photo of the specimen. This specimen represents an individual that was only about a meter long (39 inches). The specimen was part of a Soviet exhibition of fossils in Japan. Apparently, the name comes from a Japanese phonetic translation of the Cyrillic word ''gadrosavr'', or hadrosaur, and was never meant by the Russians to establish a new generic name.

Despite the only name ever applied to it being merely a mistranslation of ''gadrosavr'', this specimen has appeared in many popular dinosaur books, with varying identifications. Donald F. Glut in 1982 reported it as either an iguanodont or hadrosaur, with no crest or boot on the ischium (the lack of which are both characteristics of the crested lambeosaurine duckbills), and suggested it could be the juvenile of a previously named genus like '' Tanius'' or ''Shantungosaurus''. David Lambert in 1983 classified it as an iguanodont, but changed his mind by 1990, when it was listed as a synonym of ''Arstanosaurus'' without comment. What may be the same animal is mentioned but not named by David B. Norman and Hans-Dieter Sues in a 2000 book on Mesozoic reptiles from Mongolia and the former USSR; this material, from the Soviet-Mongolian expeditions of the 1970s, had been listed as ''Arstanosaurus'' in the Russian Academy of Sciences, and was found in the Cenomanian-age Bayan Shireh Formation of Baishin Tsav.

Averianov, Lopatin, and Tsogtbaatar in 2022 provided a preliminary description of this specimen and its taxonomic position, finding that the specimen may represent a juvenile of a novel taxon that was closely related to but more derived than the contemporary hadrosauroid '' Gobihadros''.

Gallimimus mongoliensis

"Gallimimus mongoliensis" is an informal name Rinchen Barsbold used for a nearly complete skeleton (IGM 100/14) known from the Bayan Shireh Formation, but since it differs from ''Gallimimus'' in some details, Yoshitsugu Kobayashi and Barsbold proposed in 2006 that it probably belongs to a different genus. It was recently included in a phylogenetic analysis, which recovered it as closely related to ''Tototlmimus.''

Gspsaurus

"Gspsaurus" (a ''nomen manuscriptum'') is a titanosaurian sauropod dinosaur from the Late Cretaceous Vitakri Member of the Pab Formation of Sulaiman Basin of Pakistan. It has been suggested to be synonymous with the also invalid taxon "Maojandino", also proposed by Malkani.Malkani, M.S., 2015. Dinosaurs, Mesoeucrocodiles, Pterosaurs, New Fauna and Flora from Pakistan. ''Geological Survey of Pakistan'', Information Release 823: 1–32.

Grusimimus

"Grusimimus" (or "Tsurumimus") is an informal name for an undescribed genus of ornithomimid from the Early Cretaceous (Hauterivian– Barremian) aged Shinekhudag Formation of Mongolia. Known from a skeleton including all regions except the skull, "Grusimimus" was given an invalid name in 1997 by Rinchen Barsbold, who also suggested the species name "tsuru". The specimen (GIN 960910KD) was found in 1996 and examined by Barsbold before he suggested the informal name, a ''nomen nudum''. An abstract and poster were presented on the taxon by Kobayashi & Barsbold in 2002, and the former published a thesis paper on the specimen (referred to as "Ornithomimosauria indet.") which found the taxon to be close to ''Harpymimus'' phylogenetically but possible more derived. A recent phylogenetic analysis recovered "Grusimimus" closely related to ''Beishanlong'' and ''Garudimimus.''

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Hanwulosaurus

"Hanwulosaurus" is the informal name given to an as-yet undescribed genus of dinosaur from the Late Cretaceous. It was an ankylosaur around long, which is long for an ankylosaur. Its fossils were found in Inner Mongolia, China. Much of a skeleton, including a complete skull, vertebrae, ribs, a scapula, an ulna, femora, bones from the shin, and armor, was discovered; this may be the most complete ankylosaurian skeleton yet found in Asia, according to early reports. Zhao Xijin, who has studied it, suggests that it may belong to its own subgroup within the Ankylosauria. The name first surfaced in news reports in 2001.

Heilongjiangosaurus

"Heilongjiangosaurus" (meaning " Heilongjiang lizard") is the informal name given to an as-yet undescribed genus of duckbilled dinosaur from the Late Cretaceous. It possibly was a lambeosaurine, and may in fact be the same animal as ''Charonosaurus''. The fossils were found in Maastrichtian-age rocks in Heilongjiang, China. As a ''nomen nudum'', it is unclear what material it was intended to be based on, but might be connected to the ''nomen nudum'' ''" Mandschurosaurus" jiainensis'', informally named in a 1983 publication.

The "type species" is "H. jiayinensis", and it was coined in 2001 in a faunal list by Li and Jin.

Hironosaurus

"Hironosaurus" (meaning "Hirono lizard") is the informal name given to an as-yet undescribed genus of dinosaur from the Late Cretaceous. Found in Hirono, Fukushima, Japan, it was probably a type of hadrosaur, although no subfamily identification has been made. The fossils are quite fragmentary, and consist of teeth and a vertebra, possibly from the tail. Since the fossils have never been fully described in a scientific paper, "Hironosaurus" is considered a ''nomen nudum''. It was first mentioned by Hisa in an obscure 1988 publication and was later (1990) brought to a wider audience by David Lambert. Dong Zhiming, Y. Hasegawa, and Y. Azuma regarded the material as belonging to a hadrosaurid, but lacking any characteristics to allow more precise identification (thus indeterminate).

Hisanohamasaurus

"Hisanohamasaurus" (meaning "Hisano-hama lizard") is the informal name given to an as yet undescribed genus of dinosaur from the Late Cretaceous. It is a ''nomen nudum'' known only from teeth that first appeared in a general-audience dinosaur book by David Lambert in 1990. Although initially identified a diplodocid, it later re-identified as a nemegtosaurid similar to '' Nemegtosaurus''. As its name suggests, its fossils were found in Japan. The location is part of Iwaki, Fukushima.

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Jiangjunmiaosaurus

"Jiangjunmiaosaurus" is an informal name created by an anonymous author in 1987 for a possible chimaera of ''Monolophosaurus'' and '' Sinraptor''.

Jindipelta

"Jindipelta" (Lei ''et al.'', 2019; in press) is the currently informal name given to an ankylosaur from the Zhumapu Formation in China. It is known from a partial skeleton found in Cenomanian rocks and the intended type species is "J. zouyunensis". The name was first announced in the 2019 SVP abstract book, alongside the megalosauroid '' Yunyangosaurus''.

Julieraptor

"Julieraptor" is the nickname of a dromaeosaurid fossil found in the Judith River Formation, Montana in 2002. Parts of the same skeleton were illegally excavated and nicknamed Sid Vicious in 2006, and the excavator subsequently served jail time for the theft. Bob Bakker therefore also nicknamed the specimen "Kleptoraptor". The skeleton was arranged to be sold to Royal Ontario Museum. It is known from a skeleton consisting of an almost complete skeleton missing most of its skull, most tail vertebra, part of the femur, some spinal and neck vertebra, one claw but it has a well preserved braincase.

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Kagasaurus

"Kagasaurus" (meaning "Kaga lizard") is the informal name given to an as yet undescribed genus of dinosaur from the Early Cretaceous. It was a theropod which lived in what is now Japan. The type species was named by Hisa in 1988, but is known from only two teeth. Since "Kagasaurus" has never been formally described, it is considered a ''nomen nudum''. Unlike "Kitadanisaurus" and ''Katsuyamasaurus'', it is unlikely that "Kagasaurus" is synonymous with '' Fukuiraptor'', and may instead be a dromaeosaurid.

Katsuyamasaurus

"Katsuyamasaurus" is an informal name for a genus of intermediate theropod known from the Early Cretaceous (Barremian) of the Kitadani Formation, Japan. Known from a single middle caudal vertebra and an ulna, the taxon was informally called "Katsuyama-ryu", until Lambert (1990) made it into an invalid genus name, "Katsuyamasaurus". The caudal vertebra was suggested to belong to an ornithopod by Chure (2000), and Olshevsky (2000) suggested the material was a synonym of '' Fukuiraptor''. However, the ulna differs from ''Fukuiraptor'', and the large olecranon suggests the taxon falls outside Maniraptoriformes.

Khetranisaurus

"Khetranisaurus" (meaning "Khetran lizard", for the Khetran people of Pakistan) is an informal taxon of titanosaurian sauropod from the Late Cretaceous of Balochistan, western Pakistan (also spelled "Khateranisaurus" in some early reports). The proposed species is "K. barkhani", described by M. Sadiq Malkani in 2006, and it is based on a tail vertebra, found in the Maastrichtian-age Vitakri Member of the Pab Formation. It was assigned to "Pakisauridae" (used as a synonym of Titanosauridae), along with " Pakisaurus" and "Sulaimanisaurus".

Koreanosaurus

"Koreanosaurus" (meaning "Korean lizard") is the informal name given to an as-yet undescribed genus of dinosaur from the Early Cretaceous (Aptian- Albian). It was a possible dromaeosaur (or similar theropod) which was discovered in the Gugyedong Formation