Dinosaur genera

Amargasaurus (; "La Amarga lizard") is a genus of sauropod dinosaur from the Early Cretaceous epoch (129.4–122.46 mya) of what is now Argentina. The only known skeleton was discovered in 1984 and is virtually complete, including a fragmentary skull, making Amargasaurus one of the best-known sauropods of its epoch. Amargasaurus was first described in 1991 and contains a single known species, Amargasaurus cazaui. It was a large animal, but small for a sauropod, reaching in length. Most distinctively, it sported two parallel rows of tall spines down its neck and back, taller than in any other kno

Alamosaurus (; meaning "Ojo Alamo lizard") is a genus of titanosaurian sauropod dinosaurs containing a single known species, Alamosaurus sanjuanensis, from the Maastrichtian age of the Late Cretaceous period in what is now southwestern North America. It is one of the few known titanosaurs to have inhabited North America after the nearly 30-million-year absence of sauropods from the North American fossil record ("sauropod hiatus") and probably represents an immigrant from South America.

Sauroposeidon ( ; meaning "lizard earthquake god", after the Greek god Poseidon) is a genus of sauropod dinosaur known from several incomplete specimens including a bone bed and fossilized trackways that have been found in the U.S. states of Oklahoma, Wyoming, and Texas.

Therizinosaurus (; meaning 'scythe lizard') is a genus of very large therizinosaurid dinosaurs that lived during the Late Cretaceous period in what is now Asia. It contains a single species, Therizinosaurus cheloniformis, known from the fossiliferous Nemegt Formation. The first remains of Therizinosaurus were found in 1948 by a Mongolian field expedition in the Gobi Desert and later described by Evgeny Maleev in 1954. The genus is only known from a few bones, including gigantic manual unguals (claw bones), from which it gets its name, and additional findings comprising fore and hindlimb elemen

Edmontonia is a genus of panoplosaurin nodosaurid dinosaur from the Late Cretaceous Period of what is now western North America. It is named after the Edmonton Formation (now the Horseshoe Canyon Formation in Canada), the unit of rocks where it was first found.

Ouranosaurus is a genus of herbivorous basal hadrosauriform dinosaur that lived during the Aptian stage of the Early Cretaceous of modern-day Niger and Cameroon. Ouranosaurus measured about long and weighed . Two rather complete fossils were found in the Elrhaz Formation, Gadoufaoua deposits, Agadez, Niger, in 1965 and 1970, with a third indeterminate specimen known from the Koum Formation of Cameroon. The animal was named in 1976 by French paleontologist Philippe Taquet, the type species being Ouranosaurus nigeriensis. The generic name is a combination of ourane, a word with multiple meanings

Saurolophus (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur that lived during the Late Cretaceous period of North America and Asia, in what is now the Horseshoe Canyon and Nemegt formations respectively (about 70 to 66 million years ago). It is one of the few dinosaur genera known from multiple continents. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky. Saurolophus is distinguis

Cryolophosaurus ( or ; ) is a genus of large theropod dinosaur known from only a single species, Cryolophosaurus ellioti, from the Early Jurassic of Antarctica. It was one of the largest theropods of the Early Jurassic, with the subadult, being estimated to have reached long and weighed .

Hypsilophodon (; meaning "high-crested tooth") is a neornithischian dinosaur genus from the Early Cretaceous period of England. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this into question.

Deinocheirus ( ) is a genus of large ornithomimosaur that lived during the Late Cretaceous around 70 million years ago. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Nemegt Formation of Mongolia. In 1970, this specimen became the holotype of the only species within the genus, Deinocheirus mirificus; the genus name is Greek for "horrible hand". No further remains were discovered for almost fifty years, and its nature remained a mystery. Two more complete specimens were described in 2014, which shed light on many aspects of

Tuojiangosaurus (meaning "Tuo River lizard") is a genus of herbivorous stegosaurian dinosaur from the Late Jurassic Period, recovered from the Upper Shaximiao Formation of what is now Sichuan Province in China.

Suchomimus is a genus of large theropod dinosaur that lived in what is now Niger during the Aptian to Albian stages of the Early Cretaceous period, 112 million years ago. The only known species is S. tenerensis, originally described in 1998 by paleontologist Paul Sereno and colleagues from several fossils discovered one year earlier in the Elrhaz Formation. Although these fossils come from multiple specimens, they represent one of the most anatomically well-documented spinosaurids. The animal's generic name, which means "crocodile mimic", alludes to its elongated skull and piscivorous adaptati

Heterodontosaurus is a genus of heterodontosaurid dinosaur that lived during the Early Jurassic, 200–190 million years ago. Its only known member species, Heterodontosaurus tucki, was named in 1962 based on a skull discovered in South Africa. The genus name means "different toothed lizard", in reference to its unusual, heterodont dentition; the specific name honours G. C. Tuck, who supported the discoverers. Further specimens have since been found, including an almost complete skeleton in 1966.

Achillobator ( ; meaning "Achilles hero") is a genus of large dromaeosaurid theropod dinosaur that lived during the Late Cretaceous period about 96 million to 89 million years ago in what is now the Bayan Shireh Formation of Mongolia. The genus is currently monotypic, only including the type species A. giganticus. The first remains were found in 1989 during a Mongolian-Russian field expedition and later described in 1999. Remains at the type locality of Achillobator may represent additional specimens. It represents the first and largest dromaeosaurid known from the Bayan Shireh Formation.

Dromaeosaurus (; ) is a genus of dromaeosaurid theropod dinosaur that lived during the Late Cretaceous period (middle to late Campanian and Maastrichtian), sometime between 80 and 69 million years ago, in the Canadian province of Alberta and the western United States. The type species is Dromaeosaurus albertensis, which was described by William Diller Matthew and Barnum Brown in 1922. Its fossils were unearthed in the Hell Creek Formation, Horseshoe Canyon Formation and Dinosaur Park Formation. Teeth attributed to this genus have been found in the Prince Creek Formation. Dromaeosaurus is the t

Lesothosaurus is a monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from Lesotho". The genus has only one valid species, Lesothosaurus diagnosticus. Lesothosaurus is one of the most completely-known early ornithischians, based on numerous skull and postcranial fossils from the Upper Elliot Formation. It had a simpler tooth and jaw anatomy than later ornithischians, and may have been omnivorous in some parts of the year.

Giraffatitan (name meaning "titanic giraffe") is a genus of sauropod dinosaur that lived during the late Jurassic Period (Kimmeridgian–Tithonian stages) in what is now Lindi Region, Tanzania. Only one species is known, G. brancai, named in honor of German paleontologist Wilhelm von Branca, who was a driving force behind the expedition that discovered it in the Tendaguru Formation. Giraffatitan brancai was originally described by German paleontologist Werner Janensch as a species of the North American sauropod Brachiosaurus from the Morrison Formation, as Brachiosaurus brancai. Recent rese

Centrosaurus ( ; ) is a genus of centrosaurine ceratopsid dinosaur from the Campanian age of the Late Cretaceous of Canada. Its remains have been found in the Dinosaur Park Formation, dating from 76.5 to 75.5 million years ago. The type and only species seen as valid today is Centrosaurus apertus.

Gigantoraptor () is a genus of large oviraptorosaurian dinosaur that lived in Asia during the Late Cretaceous period. It is known from the Iren Dabasu Formation of Inner Mongolia, where the first remains were found in 2005.

Irritator is a genus of spinosaurid dinosaur that lived in what is now Brazil during the Albian stage of the Early Cretaceous Period, about 113 to 110 million years ago. It is known from a nearly complete skull found in the Romualdo Formation of the Araripe Basin. Fossil dealers had acquired this skull and sold it to the State Museum of Natural History Stuttgart. In 1996, the specimen became the holotype of the type species Irritator challengeri. The genus name comes from the word "irritation", reflecting the feelings of paleontologists who found the skull had been heavily damaged and altered

Scelidosaurus (; with the intended meaning of "limb lizard", from Greek / meaning 'rib of beef' and sauros/ meaning 'lizard') is a genus of herbivorous armoured ornithischian dinosaur from the Jurassic of England.

Staurikosaurus (Pronounced /ˌstɔɹ̠ikoʊˈsɔɹ̠ʌs/, STOR-ree-koh-SOR-ruhs; "Southern Cross lizard") is a genus of herrerasaurid dinosaur from the Late Triassic of Brazil, found in the Santa Maria Formation.

Utahraptor (meaning "Utah's predator") is a genus of large dromaeosaurid (a group of feathered carnivorous theropods) dinosaur that lived during the Early Cretaceous period from around 139 to 135 million years ago in what is now the United States. The genus was described in 1993 by American paleontologist James Kirkland and colleagues with the type species Utahraptor ostrommaysi, based on fossils that had been unearthed earlier from the Cedar Mountain Formation of Utah. Later, many additional specimens were described including those from the skull and postcranium in addition to those of younge

Barapasaurus ( ) is a genus of basal sauropod dinosaur from Jurassic rocks of India. The only species is B. tagorei. Barapasaurus comes from the lower part of the Kota Formation, which is of Early to Middle Jurassic in age. It is therefore one of the earliest known sauropods. Barapasaurus is known from approximately 300 bones from at least six individuals, so that the skeleton is almost completely known except for the anterior cervical vertebrae and the skull. This makes Barapasaurus one of the most completely known sauropods from the Early Jurassic.

Sinosauropteryx (meaning "Chinese reptilian wing") is an extinct genus of coelurosaurian theropod dinosaurs. Described in 1996, it was the first dinosaur taxon outside of Avialae (birds and their immediate relatives) to be found with evidence of feathers. It was covered with a coat of very simple filament-like feathers. Structures that indicate the colour pattern have also been preserved in some of its feathers, which show that Sinosauropteryx had a countershading pattern in its body with a banded tail. The reddish brown colouration previously inferred for Sinosauropteryx is based on the melan

Huayangosaurus is a genus of stegosaurian dinosaur from the Middle Jurassic of China. The name derives from "Huayang" (華陽), an alternate name for Sichuan (the province where it was discovered), and "saurus", meaning "lizard". It lived during the Bathonian to Callovian stages, around 165 million years ago, some 20 million years before its famous relative, Stegosaurus appeared in North America. At only approximately long, it was also much smaller than its famous cousin. Found in the Lower Shaximiao Formation, Huayangosaurus shared the local Middle Jurassic landscape with the sauropods Shunosauru

Shantungosaurus () is an extinct genus of very large herbivorous saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, Shantungosaurus giganteus. The stratigraphic interval of Shantungosaurus ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. Shantungosaurus is so far the largest hadrosauroid taxon in the world, with size estimates around in length and in body mass.

Chasmosaurus ( ) is a genus of ceratopsid dinosaur from the Late Cretaceous Period in North America. Its given name means 'opening lizard', referring to the large openings (fenestrae) in its frill (Greek chasma, meaning 'opening', 'hollow', or 'gulf'; and sauros, meaning 'lizard'). With a length of and a weight of —or anywhere from 2,200 to nearly 5,000 lbs—Chasmosaurus was of a slightly smaller to "average" size, especially when compared to larger ceratopsids (such as Triceratops, which were about the size of an African bush elephant).

Mapusaurus ( 'earth lizard') is a genus of giant carcharodontosaurid carnosaurian dinosaur that lived in Argentina during the Cenomanian–Turonian ages of the Late Cretaceous. It is known from a bonebed of between seven and nine specimens, excavated from the strata of the Huincul Formation between 1997 and 2001 as part of the Argentinian-Canadian Dinosaur Project. In 2006, Rodolfo Coria and Philip J. Currie scientifically described Mapusaurus. Only one species of Mapusaurus, M. roseae, has been described, named after the rose-colored rocks in which it was discovered and sponsor Rose Letwin.

Sinornithosaurus (derived from a combination of Latin and Greek, meaning 'Chinese bird-lizard') is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (late Barremian) of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.

Majungasaurus (; ) is a genus of abelisaurid theropod dinosaur that lived in Madagascar from 70 to 66 million years ago, at the end of the Cretaceous Period, making it one of the last-known non-avian dinosaurs that went extinct during the Cretaceous–Paleogene extinction event. The genus contains a single species, Majungasaurus crenatissimus. This dinosaur is also called Majungatholus, a name which is considered a junior synonym of Majungasaurus.

Mononykus ( , sometimes ; meaning "one claw") is a genus of alvarezsaurid dinosaur that lived during the Late Cretaceous in what is now Mongolia, specifically the Nemegt Formation. Mononykus was a very small theropod, estimated around in length with a weight of . As in Shuvuuia, Mononykus likely developed a shaggy feathering. It was lightly built with long, thin legs and highly reduced and specialized forelimbs that were likely used for foraging termite mounds or other insect colonies.

Alioramus (; meaning 'different branch') is a genus of tyrannosaurid theropod dinosaurs from the Late Cretaceous period of Asia. It currently contains two species. The type species, A. remotus is known from a partial skull and three foot bones recovered from the Mongolian Nemegt Formation, which was deposited in a humid floodplain. These remains were named and described by Soviet paleontologist Sergei Kurzanov in 1976. A second species, A. altai, known from a much more complete skeleton also from the Nemegt Formation, was named and described by Stephen L. Brusatte and colleagues in 2009. Its r

Agilisaurus (; 'agile lizard') is a genus of ornithischian dinosaur from the Middle Jurassic Period of what is now eastern Asia. The only named species is A. louderbacki, recovered from the Lower Shaximiao Formation of Sichuan, China. It was about in length, in hip height, and in weight. It has leaf-shaped teeth that were well-adapted to its abrasive, plant-based diet. Most surprisingly, the wavy enamel of the teeth of this genus (and all other ornithopods), presumed to make them more resistant to wear, was previously thought to be exclusive to hadrosaurs. This is also the case for Changchunsa

Anchisaurus is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Upper Portland Formation, Northeastern United States, which was deposited from the Hettangian age into the Sinemurian age, between about 200 and 192 million years ago. Until recently it was classed as a member of Prosauropoda. The genus name Anchisaurus comes from the Greek αγχι (') ; "near, close" + Greek ('); "lizard". Anchisaurus was coined as a replacement name for "Amphisaurus", which was itself a replacement name for Hitchcock's "

Saltasaurus (which means "lizard from Salta") is a genus of saltasaurid dinosaur of the Late Cretaceous period of Argentina. Small among sauropods, though still heavy by the standards of modern creatures, Saltasaurus was characterized by a short neck and stubby limbs. It was the first genus of sauropod known to possess armour of bony plates embedded in its skin. Such small bony plates, called osteoderms, have since been found on other titanosaurians.

Megaraptor () is a genus of large theropod dinosaur, the type genus and namesake of the clade Megaraptora and family Megaraptoridae. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America, dating to the Turonian and Coniacian ages of the Late Cretaceous, roughly 90–88 million years ago. One species of Megaraptor, M. namunhuaiquii, has thus been named, known from seven partial or fragmentary skeletons, with only two including skull elements.

Acanthopholis (; meaning "spiny scales") is a genus of ankylosaurian dinosaur in the family Nodosauridae that lived during the Late Cretaceous Period of England. A single species, A. horrida, exists.

Titanosaurus (; ) is a dubious genus of sauropod dinosaurs, first described by Richard Lydekker in 1877. It is known from the Maastrichtian (Upper Cretaceous) Lameta and Kallakurichi Formations of India.

Monolophosaurus ( ; meaning "single-crested lizard") is an extinct genus of tetanuran theropod dinosaur from the Middle Jurassic Shishugou Formation in what is now Xinjiang, China. It was named for the single crest on top of its skull. Monolophosaurus was a mid-sized theropod at about long and weighed .

Ornitholestes (from Ancient Greek ὄρνις (órnis), meaning "bird", and λῃστής (lēistḗs), meaning "robber", and thus, "bird robber") is a small theropod dinosaur of the late Jurassic (Brushy Basin Member of the Morrison Formation, middle Kimmeridgian age, about 154 million years ago) of Western Laurasia (the area that was to become North America).

Leaellynasaura (meaning "Leaellyn's lizard") is a genus of small herbivorous ornithischian dinosaurs from the late Aptian to early Albian stage of the Early Cretaceous, around 118-110 million years ago. It was first discovered in Dinosaur Cove, Australia. The only known species is Leaellynasaura amicagraphica. It was described in 1989, and named after Leaellyn Rich, the daughter of the Australian palaeontologist couple Tom Rich and Patricia Vickers-Rich who discovered it. The specific name, amicagraphica, translates to "friend writing" and honours both the Friends of the Museum of Victoria and

Yutyrannus (meaning "feathered tyrant") is a genus of proceratosaurid tyrannosauroid dinosaur which contains a single known species, Yutyrannus huali. This species lived during the early Cretaceous period in what is now northeastern China. Three fossils of Yutyrannus huali — all found in the rock beds of Liaoning Province — are the largest-known dinosaur specimens that preserve direct evidence of feathers.

Leptoceratops (meaning 'small horn face') is a genus of ceratopsian dinosaur from the Late Cretaceous of North America. First found in Alberta in 1910, the type species Leptoceratops gracilis was named in 1914 by Barnum Brown for a partial skull and skeleton of two individuals found in the Scollard Formation of Alberta. Additional specimens found in the Scollard include one complete and two mostly complete skeletons together, uncovered in 1947 by Charles M. Sternberg. Specimens from Montana that were among the earliest referred to Leptoceratops have since been moved to their own genera Montano

Hadrosaurus (; ) is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation in New Jersey about 83.6 to 77.9 million years ago. The holotype specimen was found in fluvial marine sedimentation, meaning that the corpse of the animal was transported by a river and washed out to sea. Some fossils are found in the Tar Heel/Coachman Formation.

Thecodontosaurus ("socket-tooth lizard") is a genus of herbivorous basal sauropodomorph dinosaur that lived during the late Triassic period (Carnian age). Its remains are known mostly from Triassic "fissure fillings" in southern England. Thecodontosaurus was a small bipedal animal, about long. It is one of the first dinosaurs to be discovered and is one of the oldest that ever existed. Many species have been named within the genus, but only the type species Thecodontosaurus antiquus is seen as valid today.

Polacanthus (from the Ancient Greek polys-/πολύς- "many" and akantha/ἄκανθα "thorn" or "prickle") is an extinct genus of ankylosaurian dinosaurs from the early Cretaceous (130–125 million years ago) of England. Several species have been named in the genus Polacanthus, but only the type species, Polacanthus foxii, is currently seen as valid. There are not many fossil remains of this dinosaur, and some important anatomical features, such as its skull, are poorly known. It grew to about long. Its body was covered with armour plates and spikes. It may be a basal member of the Nodosauridae or part

Segnosaurus is a genus of therizinosaurid dinosaur that lived in what is now southeastern Mongolia during the Late Cretaceous, about 102–86 million years ago. Multiple incomplete but well-preserved specimens were discovered in the Gobi Desert in the 1970s, and in 1979 the genus and species Segnosaurus galbinensis were named. The generic name Segnosaurus means "slow lizard" and the specific name galbinensis refers to the Galbin region. The known material of this dinosaur includes the lower jaw, neck and tail vertebrae, the pelvis, shoulder girdle, and limb bones. Parts of the specimens hav

Alvarezsaurus (; "Don Gregorio Alvarez's lizard") is a genus of alvarezsaurid dinosaur from the Late Cretaceous, living in Argentina approximately 86 - 83 million years ago. It was a small dinosaur, measuring long and weighing approximately . It was found in the Bajo de la Carpa Formation and was named by paleontologist José Bonaparte in 1991 after the historian Don Gregorio Alvarez. The type species is A. calvoi.

Masiakasaurus is a genus of small predatory theropod dinosaurs from the Late Cretaceous of Madagascar. In Malagasy, masiaka means "vicious"; thus, the genus name means "vicious lizard". The type species, Masiakasaurus knopfleri, was named after the musician Mark Knopfler, whose music inspired the expedition crew. It was named in 2001 by Scott D. Sampson, Matthew Carrano, and Catherine A. Forster. Unlike most theropods, the front teeth of Masiakasaurus projected forwards instead of straight down. This unique dentition suggests that they had a specialized diet, perhaps including fish and other s

Rahonavis is a genus of bird-like theropod from the Late Cretaceous (Maastrichtian, from about 70 to 66 mya) of what is now northwestern Madagascar. It is known from a partial skeleton (UA 8656) found by Catherine Forster and colleagues in Maevarano Formation rocks at a quarry near Berivotra, Mahajanga Province. Rahonavis was a small predator, at about long and 0.45-2.27 kg (1-5 lbs), with the typical dromaesaurid-like raised sickle claw on the second toe. It was the first coelurosaur discovered in Africa, with Nqwebasaurus being the second.

Saurornithoides ( ) is a genus of troodontid maniraptoran dinosaur, which lived during the Late Cretaceous period. These creatures were predators, which could run fast on their hind legs and had excellent sight and hearing. The name is derived from the Greek stems saur~ (lizard), ornith~ (bird) and eides (form), referring to its bird-like skull.

Scutellosaurus ( ) is a genus of basal thyreophoran dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now Arizona, USA. It is classified in Thyreophora, the armoured dinosaurs; its closest relatives may have been Emausaurus and Scelidosaurus, another armored dinosaur which was mainly a quadrupedal dinosaur, unlike bipedal Scutellosaurus. It is one of the earliest representatives of the armored dinosaurs and the basalmost form discovered to date. Scutellosaurus was a small, lightly-built, ground-dwelling herbivore, that could grow up

Aegyptosaurus (meaning 'Egypt's lizard') is a genus of sauropod dinosaur discovered in Egypt, that lived in what is now Africa, around 95 million years ago, during the Late Cretaceous Period (Cenomanian faunal stage).

Bambiraptor is a genus of bird-like dromaeosaurid theropod dinosaur that lived during the Late Cretaceous (about 72 million years ago) of Montana. It was described by scientists at the University of Kansas, Yale University, and the University of New Orleans. The holotype fossil is less than long, although this specimen appears to be a juvenile, and it is possible that Bambiraptor is a juvenile Saurornitholestes. It is even suspected that the type specimen is a chimera, based on the fact that "there are elements of three different similarly sized lower legs included in the holotype." Because of

Bagaceratops (meaning "small-horned face") is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 72 to 71 million years ago. Bagaceratops remains have been reported from the Barun Goyot Formation and Bayan Mandahu Formation. One specimen may argue the possible presence of Bagaceratops in the Djadochta Formation.

Cetiosaurus ( meaning 'whale lizard', from the Greek ''''/ meaning 'sea monster' (later, 'whale') and ''''/ meaning 'lizard'), is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 171 to 165 million years ago during the Bajocian and Bathonian ages in what is now Britain and probably France.

Zuniceratops ('Zuni horned face') is a genus of ceratopsian dinosaurs that lived during the Turonian stage of the Late Cretaceous in what is now New Mexico, United States. Only a single species is known, Zuniceratops christopheri.

Caudipteryx (meaning "tail feather") is a genus of small oviraptorosaurian dinosaurs that lived in China during the Early Cretaceous, around 124.6 million years ago. They were feathered and extremely bird-like in their overall appearance, to the point that some paleontologists suggested it was a bird. Two species have been described: C. zoui (the type species), in 1998, and C. dongi, in 2000. Caudipteryx had a stout trunk, long legs, and was probably a swift runner. Its discovery has led to many intensive studies and debate over the relationship between birds and dinosaurs.

Dryosaurus ( , meaning 'tree lizard', Greek '''' () meaning 'tree, oak' and () meaning 'lizard' (the name reflects the forested habitat, not a vague oak-leaf shape of its cheek teeth as is sometimes assumed)) is an extinct genus of herbivorous ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont (formerly classified as a hypsilophodont). Fossils have been found in the western United States and were first discovered in the late 19th century. Valdosaurus canaliculatus and Dysalotosaurus lettowvorbecki were both formerly considered to represent species of Dryosaurus.