History UsefulNotes / PrehistoricLifeHadrosaurPredecessors

Among non-hadrosaur/non-''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Iguanodon]]'' ornithopods, the ones you've more chances to see in media are: ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Hypsilophodon]]'' (the prototype of the "hypsilophodonts" aka small-slender members of the Group); ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Camptosaurus]]'' & ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Dryosaurus]]'' (the two iconic ornithopods from the Late Jurassic; the former was big and Iguanodon-like, the latter small and Hypsilophodon-like): ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Tenontosaurus]]'' (looking like it's in the middle between an ''Iguanodon'' and a ''Hypsilophodon'', but with a distinctively long tail); and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' (with an evident crest on its back, it's traditionally considered an "iguanodont" but was actually closer to hadrosaurs). Among the other examples, the "iguanodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]'' and the "hypsilophodont" ''Leaellynasaura'' (both Australian) [[note]]The latter, according to recent research, could not be a proper ornithopod however.[[/note]] were portrayed in 1999 by ''Series/WalkingWithDinosaurs'', while ''Orodromeus'' and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Thescelosaurus]]'' (both "hypsilophodonts") have had notable ScienceMarchesOn stories.

''Hypsilophodon'' is classically countered against ''Iguanodon'', which is the traditional prototype of the the “iguanodonts” (large/heavy non-hadrosaurian ornithopods). [[ScienceMarchesOn Now scientists have found]] “hypsilophodonts” is an artificial assemblage including the most basal ornithopods, while “iguanodonts” now indicates a natural group including not only the most ''Iguanodon''-like animals but also [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]], pre-duckbills and also some traditional “hypsilophodontians” (see below).

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hypsilophodonbrussels.jpg[[caption-width-right:350:One of the [[{{Irony}} hugest]] dinosaurs known.[[note]]It was no bigger than a dog.]]]]

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hypsilophodonbrussels.jpg[[caption-width-right:350:One of the [[{{Irony}} hugest]] dinosaurs known.]]]]

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hypsilophodonbrussels.jpg]]

''Hypsilophodon'' is classically countered against ''Iguanodon'', which is the traditional prototype of the the “iguanodonts” (large/heavy non-hadrosaurian ornithopods). [[ScienceMarchesOn Now scientists have found]] “hypsilophodonts” is an artificial assemblage including the most basal ornithopods, while “iguanodonts” now indicates a natural group including not only the most ''Iguanodon''-like animals but also duckbills, pre-duckbills and also some traditional “hypsilophodontians” (see below).

Among non-hadrosaur/non-''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Iguanodon]]'' ornithopods, the ones you've more chances to see in media are: ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Hypsilophodon]]'' (the prototype of the "hypsilophodonts" aka small-slender members of the Group); ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Camptosaurus]]'' & ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Dryosaurus]]'' (the two iconic ornithopods from the Late Jurassic; the former was big and Iguanodon-like, the latter small and Hypsilophodon-like): ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Tenontosaurus]]'' (looking like it's in the middle between an ''Iguanodon'' and a ''Hypsilophodon'', but with a distinctively long tail); and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' (with an evident crest on its back, it's traditionally considered an "iguanodont" but was actually closer to hadrosaurs). Among the other examples, the "iguanodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]'' and the "hypsilophodont" ''Leaellynasaura'' (both Australian) [[note]]The latter, according to recent research, could not be a proper ornithopod however.[[/note]] were portrayed in 1999 by ''Series/WalkingWithDinosaurs'', while ''Orodromeus'' and ''Thescelosaurus'' (both "hypsilophodonts") have had notable ScienceMarchesOn stories.

'''The Last Gazelle had a Heart of Stone?:''' ''[[http://en.wikipedia.org/wiki/Thescelosaurus Thescelosaurus]]''

* The two most famous "hypsilophodonts", ''Hypsilophodon foxi'' and ''Dryosaurus altus'', lived in Early Cretaceous and Late Jurassic respectively: but Hypsilophodon-like animals existed also in Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period: hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs. In North-America, while [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]] ruled the “wildebeest” role played by the camptosaurs in the Jurassic and by the ''Iguanodon''s in Early Cretaceous, the “gazelle” one was mainly played by ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya. Rather similar to ''Dryosaurus'' in appearence, it was once placed in the monotypic Thescelosaurid family, and sometimes believed a small iguanodont like ''Dryosaurus'' or another late-survivor, the european ''Rhabdodon'': but cladistic research have revealed it was not a basal iguanodont unlike the latter. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not-visible in the living animal. Recently, ''Hypsilophodon'' as well has revealed these osteoderms, which were arguably for defense. ''Thescelosaurus'' is the animal from which the controversial “fossilized heart” comes from, which is almost certainly a fossilization artifact: that is, a piece of stone found in one specimen, which casually resembles a heart. Discovered in year 2000, this stony concretion was celebrated as the proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothized in the late 2000s. ''Thescelosaurus'' was one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era, just like ''Tyrannosaurus rex'' and ''[[TemperCeratops Triceratops]]'', other than ''Edmontosaurus'', ''Ankylosaurus'', and others, all from the Hell Creek Formation.

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* The two most famous "hypsilophodonts", ''Hypsilophodon foxi'' and ''Dryosaurus altus'', lived in Early Cretaceous and Late Jurassic respectively: but Hypsilophodon-like animals existed also in Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period: hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs. In North-America, while [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]] ruled the “wildebeest” role played by the camptosaurs in the Jurassic and by the ''Iguanodon''s in Early Cretaceous, the “gazelle” one was mainly played by ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya. Rather similar to ''Dryosaurus'' in appearence, it was once placed in the monotypic Thescelosaurid family, and sometimes believed a small iguanodont like ''Dryosaurus'' or another late-survivor, the european ''Rhabdodon'': but cladistic research have revealed it was not a basal iguanodont unlike the latter. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not-visible in the living animal. Recently, ''Hypsilophodon'' as well has revealed these osteoderms, which were arguably for defense. ''Thescelosaurus'' is the animal from which the controversial “fossilized heart” comes from, which is almost certainly a fossilization artifact: that is, a piece of stone found in one specimen, which casually resembles a heart. Discovered in year 2000, this stony concretion was celebrated as the proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothized in the late 2000s. ''Thescelosaurus'' was one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era, just like ''TyrannosaurusRex'' and ''[[TemperCeratops Triceratops]]'', other than ''Edmontosaurus'', ''Ankylosaurus'', and others, all from the Hell Creek Formation.

* As a whole, non-hadrosaurian ornithopods have been found everywhere, even in Antarctica (as we'll see later). Almost all the main dinosaurian faunas had at least one known ornithopod: even the famous Late Cretaceous islets which were where today is Central Europe. ''Rhabdodon priscus'' was a sort of “dwarf iguanodont”, a primitive spike-less iguanodontian analogue to the earlier ''Dryosaurus'' and ''Tenontosaurus''; it was a late-surviving form which managed to reach the K/T extinction event just thanks to its insulation and absence of competition from the much more evolved hadrosaurs. But wait: some hadrosaurs are ''actually'' known as well from that habitat, such as ''[[UsefulNotes/PrehistoricLifeHadrosaurs Telmatosaurus]]''; only, they too were small and primitive. From the same fauna are the close ''Rhabdodon'' relatives ''Mochlodon'' and ''Zalmoxes''. On the other hand, the 3/4 m long ''Callovosaurus'' found in England comes from a far more ancient period: the Callovian stage of the Middle Jurassic (hence the name). It was one of the most ancient iguanodontians known: once considered a camptosaurid, it's actually more closely related to ''Dryosaurus''. ''Valdosaurus'' ("Weald lizard") was another dryosaurid, also English but Early Cretaceous (like ''Hypsilophodon''); some alleged "Valdosaurus" remains were found in Africa, too. ''Kangnasaurus'' was bigger, and lived in Early Cretaceous South Africa: known from scanty remains, it owes its name from a local Ranch. ''Phyllodon'', ''Alocodon'', ''Taveirosaurus'', and ''Trimucrodon'' from Portugal are known only from teeth, and are thus hard to classify.

* The two most famous "hypsilophodonts", ''Hypsilophodon foxi'' and ''Dryosaurus altus'', lived in Early Cretaceous and Late Jurassic respectively: but Hypsilophodon-like animals existed also in Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period: hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs. In North-America, while [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]] ruled the “wildebeest” role played by the camptosaurs in the Jurassic and by the ''Iguanodon''s in Early Cretaceous, the “gazelle” one was mainly played by ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya. Rather similar to ''Dryosaurus'' in appearence, cladistic research have revealed it was not a basal iguanodont unlike the latter. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not-visible in the living animal. Recently, ''Hypsilophodon'' as well has revealed these osteoderms, which were arguably for defense. ''Thescelosaurus'' is the animal from which the controversial “fossilized heart” comes from, which is almost certainly a fossilization artifact: that is, a piece of stone found in one specimen, which casually resembles a heart. Discovered in year 2000, this stony concretion was celebrated as the proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothized in the late 2000s. ''Thescelosaurus'' was one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era, just like ''TyrannosaurusRex'' and ''[[TemperCeratops Triceratops]]'', other than ''Edmontosaurus'', ''Ankylosaurus'', and others.

* The two most famous "hypsilophodonts", ''Hypsilophodon foxi'' and ''Dryosaurus altus'', lived in Early Cretaceous and Late Jurassic respectively: but Hypsilophodon-like animals existed also in Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period: hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs. In North-America, while [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]] ruled the “wildebeest” role played by the camptosaurs in the Jurassic and by the ''Iguanodon''s in Early Cretaceous, the “gazelle” one was mainly played by ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya. Rather similar to ''Dryosaurus'' in appearence, cladistic research have revealed it was not a basal iguanodont unlike the latter. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not-visible in the living animal. Recently, ''Hypsilophodon'' as well has revealed these osteoderms, which were arguably for defense. ''Thescelosaurus'' is the animal from which the controversial “fossilized heart” comes from, which is almost certainly a fossilization artifact: that is, a piece of stone found in one specimen, which casually resembles a heart. Discovered in year 2000, this stony concretion was celebrated as the proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothized in the late 2000s. ''Thescelosaurus'' was one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era, just like TyrannosaurusRex and ''Triceratops''.

* There were other “hypsilophodontians” from Late Cretaceous North America that were smaller and lived slightly earlier than it. ''Orodromeus makelai'' ("Makela's runner of the [Egg] Mountain") was discovered in Montana in year 1988 by Jack Horner and his assistant Robert [[ExactlyWhatItSaysOnTheTin Makela]] in the same site in which they had found ''Maiasaura peeblesorum'' eight years before. They noted some small unusually spiral-shaped nests full of eggs containing fossilized embryos, next to the bigger & more famous ''Maiasaura'' ones, which they attributed to ''Orodromeus'': as the bones inside those eggs were already well-formed, they said that the orodromeus' hatchlings were more independent after birth than the maiasaura's ones. ScienceMarchesOn however, and later it was found that those eggs/embryos were from the theropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Troodon]]'' instead. The ironical thing is, fossils of troodonts were discovered as well around those putative ''Orodromeus'' nests, but it was thought that they were actually preying on Orodromeus nestlings: an astonishingly similar story to the “Oviraptor robbing Protoceratops' eggs”. Found in 2007, its relative ''[[http://en.wikipedia.org/wiki/Oryctodromeus Oryctodromeus]]'' ("digging runner") lived quite a bit earlier than the [[NamesTheSame similar-named]] ''Orodromeus'' in Middle Cretaceous, but has also shown the first proof of digging behavior among non-avian dinosaurs: its skeleton has been found inside a fossilized burrow. Another relative found in Alberta is known since the start of the XX century: ''[[http://en.wikipedia.org/wiki/Parksosaurus Parksosaurus]]'' ("William Parks' lizard", sometimes misspelled "''Parkosaurus''"). Similar in size and shape to ''Orodromeus'' but living few million years later, it could be actually closer to ''Thescelosaurus'' (which lived even later), and has recently become the namesake of its own family of ornithopods, the Parksosaurids. ''[[http://en.wikipedia.org/wiki/Zephyrosaurus Zephyrosaurus]]'' ("lizard of the western wind"), lived earlier than all these, in the Early Cretaceous Montana: it could have met ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Deinonychus]]'' in real life, and possibly was one of its preys.

'''Heart of Stone:''' ''[[http://en.wikipedia.org/wiki/Thescelosaurus Thescelosaurus]]''

* Since its first discovery made in the first decades of the XIX Century, ''Iguanodon'' remains have been found everywhere from Africa to Mongolia, Europe and North America; ''Series/ChasedByDinosaurs'' added some sorta iguanodons even in South American settings - even though some iguanodontians ''are'' known from South America, they were much smaller. ScienceMarchesOn however, and now many of these ''Iguanodon'' species have been reclassified in other genera, while a formerly distinct iguanodontid genus, "Vectisaurus" from Early Cretaceous England, is now classified within ''Iguanodon''. Several genera from Europe have been created as an homage to some of the greatest XIX century paleontologists - at the time, dinosaur remains were mainly from ''Iguanodon''s. So we have ''Mantellisaurus atherfieldensis'' from Gideon Mantell (''Iguanodon''’s TropeNamer); formerly "Iguanodon atherfieldensis", it was found in the same coal mine near Bernissart in Belgium in which the 30 or so skeletons of the more robust ''Iguanodon bernissartensis'' have been dug out.[[note]]In the same mine were found the teeth of ''Craspedodon'', a putative iguanodontian which could be an unusually European ceratopsian according to recent research.[[/note]] Then, ''Owenodon'' from Richard Owen (dinosaurs’ TropeNamer), and ''Dollodon'' from Louis Dollo, the guy who described the famous iguanodonts found in the “Dinosaur Mine” in Belgium as erect bipedal beasts. [[note]]However, ''Dollodon'' is very likely the same as ''Mantellisaurus''.[[/note]] Another former ''Iguanodon'' species has been renamed "Huxleysaurus" (after Thomas Henry Huxley, supporter of Darwin's theory of evolution), but this name is unofficial at present. Other Europeans were named for their unique physical characteristics, such as ''Hypselospinus'' ("tall spines") and ''Barilium'' ("heavy hips"). The North American ''Iguanodon lakotaensis'' was renamed ''[[http://en.wikipedia.org/wiki/Dakotadon Dakotadon]]'' after the state it was found in. A similar fate befell another South Dakotan iguanodont: ''Osmakasaurus'', from the same rock unit as ''Dakotadon'', was originally named as a species of ''Camptosaurus''. True camptosaurids include ''Bihariosaurus'' from Romania, ''Draconyx'' from Portugal, and maybe North American ''Theiophytalia''. Finally, the Mongolian specimen "Iguanodon orientalis" has been renamed ''Altirhinus kurzanovi''. As with most former ''Iguanodon'' specimens, ''Altirhinus'' was actually closer to hadrosaurs than to ''Iguanodon''. Indeed its name, “high nose”, was given from its humped nose similar to the duckbill ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Gryposaurus]]''. Interesting that Kron (the villainous ''Iguanodon'' in WesternAnimation/{{Dinosaur}}) has a hump-nose that could mean he’s actually an ''Altirhinus''.

* An even more primitive ornithopod from the same period of ''Callovosaurus'' was the Chinese “hypsilophodont” ''Yandusaurus'', once considered the most basal true ornithopod known to science. It was originally named "Yubasaurus", but since that name was not made official, ''Yandusaurus'' got the precedence. Other “hypsilophodonts" from the same fauna were also too primitive to be real ornithopods. The most scientifically-known is ''Agilisaurus'' ("agile lizard"); others are ''Xiaosaurus'', ''Gongbusaurus'', and former ''Yandusaurus'' species ''Hexinlusaurus''. From Early Cretaceous China comes the enigmatic true-ornithopod ''[[http://en.wikipedia.org/wiki/Jeholosaurus Jeholosaurus]]'' (named after the geological formation it was dug out), whose pointed frontal teeth seem indicating an omnivorous diet.

'''Icy Amnesia:''' The "Antarctic hypsilophodont"

'''Chinese Gazelles:''' ''[[http://en.wikipedia.org/wiki/Yandusaurus Yandusaurus]]'' & ''[[http://en.wikipedia.org/wiki/Agilisaurus Agilisaurus]]''

* An even more primitive ornithopod from the same period of ''Callovosaurus'' was the Chinese “hypsilophodont” ''Yandusaurus'', once considered the most basal true ornithopod known to science. It was originally named "Yubasaurus", but since that name was not made official, ''Yandusaurus'' got the precedence. Other “hypsilophodonts" from the same fauna were also too primitive to be real ornithopods. The most scientifically-known is ''Agilisaurus'' ("agile lizard"); others are ''Xiaosaurus'', ''Gongbusaurus'', and former ''Yandusaurus'' species ''Hexinlusaurus''. From Early Cretaceous China comes the enigmatic true-ornithopod ''[[http://en.wikipedia.org/wiki/Jeholosaurus Jeholosaurus]]'' (named after the geological formation it was dug out), whose pointed frontal teeth seem indicating an omnivorous diet.

'''A Never-ending Rivarly:''' ''[[http://en.wikipedia.org/wiki/Othnielosaurus Othnielosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Drinker_(dinosaur) Drinker]]''

* Travelling in Late Jurassic USA, other than ''Camptosaurus'' the Wildebeest and ''Dryosaurus'' the Gazelle we'd encounter also ''Othnielosaurus'' the Dik-Dik. This was indeed a very small animal, 1.5 m long (smaller than an ''Hypsilophodon''), with a very convoluted ScienceMarchesOn story. It was described in 1977 as ''[[http://en.wikipedia.org/wiki/Othnielia Othnielia rex]]'' ("Othnielia" is the name usually heard in docu-media), and renamed more recently because its type material was not diagnostic. Both curious names derive from [[http://en.wikipedia.org/wiki/Othniel_Charles_Marsh Othniel Charles Marsh]], one of the two scientists who “fought” the Bone-Wars in the XIX century. As it seems, its notorious rivalry with [[http://en.wikipedia.org/wiki/Edward_Drinker_Cope Edward Drinker Cope]] has lasted until today, with another similar animal from the same habitat named ''Drinker nisti'' in 1990 out of spite! To complicate the matter, we also have ''[[http://en.wikipedia.org/wiki/Nanosaurus Nanosaurus]]'' and ''[[http://en.wikipedia.org/wiki/Laosaurus Laosaurus]]''. Discovered during Cope’s and Marsh’s “war”, ''Nanosaurus agilis'' ("agile dwarf lizard") was very commonly-portrayed in old textbooks for having detained the record of “the smallest North-American dinosaur” for almost a century... but today it might not even be a valid name. Today, the record pertains to a tiny heterodontosaurid found only in 2009, ''[[UsefulNotes/PrehistoricLifePrimitiveOrnithischians Fruitadens]]''. The very fragmentary ''Laosaurus celer'' ("speedy fossil lizard", described in USA in the same period of ''Nanosaurus'') has been involved in this taxonomic tangle as well, with its remains often found mixed with those of ''Dryosaurus''.

'''Icy Amnesia:''' The "Antarctic hypsilophodont"

* Finally, let’s not forget the “Mysterious Polar Dino”. In year 1987, just one year after the ankylosaur named ''Antarctopelta'' in 2006, the second Antarctic dinosaur was found, described as a “polar hypsilophodont”; the thing is, it has had an even worse fate than the ankylosaur itself. At least, after 20 years of waiting, the latter ''has'' received a name; the polar "hypsy" ''has yet to wait a formal naming and description'', and sadly seems to be almost forgotten today. Partially compensating, several small bipedal ornithischians have been then discovered in other southern continents, the best-known being ''Leaellynasaura amicagraphica''. It was found in 1989 in Australia along with the single lower jaw of the larger ''[[http://en.wikipedia.org/wiki/Atlascopcosaurus Atlascopcosaurus loadsi]]'', so-called from the Atlas-Copco Corporation that funded its excavation. Today, the most-complete Australian "hypsilophodont" is ''[[http://en.wikipedia.org/wiki/Qantassaurus Qantassaurus]]'' (its name is a homage to Qantas, the LandDownUnder airlines). However, there's another relative discovered in Australia at the start of the XX century, but is known only from a femur: ''[[http://en.wikipedia.org/wiki/Fulgurotherium Fulgurotherium australe]]'' (the "lightening beast of the South"). Its name is odd because recalls more that of a prehistoric mammal (''"[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Uintatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Hyracotherium]]"'', and so on) than that of a dinosaur. About South American discoveries, apart from the enigmatic ''Loncosaurus'' (found as well in the early XX century but described from a single femur mixed with a theropod tooth), there are few non-hadrosaur ornithopods found in the 2000s, the largest one being the 6 m long ''[[http://en.wikipedia.org/wiki/Macrogryphosaurus Macrogryphosaurus]]''. Curiously, one small South American ornithopod described in 1996 [[FollowTheLeader has got]] a feminine name reminescent of ''Leaellynasaura'': ''[[http://en.wikipedia.org/wiki/Gasparinisaura Gasparinisaura]]'' ("Gasparini's lizard"). Since that other small ornithischians around the world have received the suffix "-saura", for example "Bugenasaura" (now regarded as a synonym of ''Thescelosaurus'') and, last example, ''[[http://en.wikipedia.org/wiki/Trinisaura Trinisaura]]'', found in Antarctica in the earliest part of 2013 (this one has immediately received a name). Well, [[TheUnfairSex Unfair Sex]] -related names do fit better for [[AnimalMotifs these graceful “gazelle dinos”]] rather than the badass-looking ([[AnimalMotifs and very masculine]]) ankylosaurs.

Among non-hadrosaur/non-''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Iguanodon]]'' ornithopods, the ones you've more chances to see in media are: ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Hypsilophodon]]'' (the prototype of the "hypsilophodonts" aka small-slender members of the Group); ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Camptosaurus]]'' & ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Dryosaurus]]'' (the two iconic ornithopods from the Late Jurassic; the former was big and Iguanodon-like, the latter small and Hypsilophodon-like): ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Tenontosaurus]]'' (looking like it's in the middle between an ''Iguanodon'' and a ''Hypsilophodon'', but with a distinctively long tail); and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' (with an evident crest on its back, it's traditionally considered an "iguanodont" but was actually closer to hadrosaurs). Among the other examples, the "iguanodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]'' and the "hypsilophodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Leaellynasaura]]'' (both Australian) [[note]]The latter, according to recent research, could not be a proper ornithopod however.[[/note]] were portrayed in 1999 by ''Series/WalkingWithDinosaurs'', while ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Orodromeus]]'' and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Thescelosaurus]]'' (both "hypsilophodonts") have had notable ScienceMarchesOn stories.

'''Iguanodons everywhere?:''' ''[[http://en.wikipedia.org/wiki/Mantellisaurus Mantellisaurus]]'' & ''[[http://en.wikipedia.org/wiki/Altirhinus Altirhinus]]''

'''Hadrosaur relatives:''' ''[[http://en.wikipedia.org/wiki/Protohadros Protohadros]]'' and ''[[http://en.wikipedia.org/wiki/Eolambia Eolambia]]''

'''More primitive guys:''' ''[[http://en.wikipedia.org/wiki/Rhabdodon Rhabdodon]]'' & ''[[http://en.wikipedia.org/wiki/Callovosaurus Callovosaurus]]''

'''A never-ending rivarly:''' ''[[http://en.wikipedia.org/wiki/Othnielosaurus Othnielosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Drinker_(dinosaur) Drinker]]''

'''Icy amnesia:''' The "Antarctic hypsilophodont"

* Finally, let’s not forget the “Mysterious Polar Dino”. In year 1987, just one year after the ankylosaur named ''Antarctopelta'' in 2006, the second Antarctic dinosaur was found, described as a “polar hypsilophodont”; the thing is, it has had an even worse fate than the ankylosaur itself. At least, after 20 years of waiting, the latter ''has'' received a name; the polar "hypsy" ''has yet to wait a formal naming and description'', and sadly seems to be almost forgotten today. Partially compensating, several small bipedal ornithischians have been then discovered in other southern continents, the best-known being ''Leaellynasaura amicagraphica''. It was found in 1989 in Australia along with the single lower jaw of the larger ''[[http://en.wikipedia.org/wiki/Atlascopcosaurus Atlascopcosaurus loadsi]]'', so-called from the Atlas-Copco Corporation that funded its excavation. Today, the most-complete Australian "hypsilophodont" is ''[[http://en.wikipedia.org/wiki/Qantassaurus Qantassaurus]]'' (its name is a homage to Qantas, the LandDownUnder airlines). However, there's another relative discovered in Australia at the start of the XX century, but is known only from a femur: ''[[http://en.wikipedia.org/wiki/Fulgurotherium Fulgurotherium australe]]'' (the "lightening beast of the South"). Its name is odd because recalls more that of a prehistoric mammal (''"[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Uintatherium]]"'', and so on) than that of a dinosaur. About South American discoveries, apart from the enigmatic ''Loncosaurus'' (found as well in the early XX century but described from a single femur mixed with a theropod tooth), there are few non-hadrosaur ornithopods found in the 2000s, the largest one being the 6 m long ''[[http://en.wikipedia.org/wiki/Macrogryphosaurus Macrogryphosaurus]]''. Curiously, one small South American ornithopod described in 1996 [[FollowTheLeader has got]] a feminine name reminescent of ''Leaellynasaura'': ''[[http://en.wikipedia.org/wiki/Gasparinisaura Gasparinisaura]]'' ("Gasparini's lizard"). Since that other small ornithischians around the world have received the suffix "-saura", for example "Bugenasaura" (now regarded as a synonym of ''Thescelosaurus'') and, last example, ''[[http://en.wikipedia.org/wiki/Trinisaura Trinisaura]]'', found in Antarctica in the earliest part of 2013 (this one has immediately received a name). Well, [[TheUnfairSex Unfair Sex]] -related names do fit better for [[AnimalMotifs these graceful “gazelle dinos”]] rather than the badass-looking ([[AnimalMotifs and very masculine]]) ankylosaurs...

* Travelling in Late Jurassic USA, other than ''[[UsefulNotes/StockDinosaursTrueDinosaurs Camptosaurus]]'' the Wildebeest and ''[[UsefulNotes/StockDinosaursTrueDinosaurs Dryosaurus]]'' the Gazelle we'd encounter also ''Othnielosaurus'' the Dik-Dik. This was indeed a very small animal, 1.5 m long (smaller than an ''Hypsilophodon''), with a very convoluted ScienceMarchesOn story. It was described in 1977 as ''[[http://en.wikipedia.org/wiki/Othnielia Othnielia rex]]'' ("Othnielia" is the name usually heard in docu-media), and renamed more recently because its type material was not diagnostic. Both curious names derive from [[http://en.wikipedia.org/wiki/Othniel_Charles_Marsh Othniel Charles Marsh]], one of the two scientists who “fought” the Bone-Wars in the XIX century. As it seems, its notorious rivalry with [[http://en.wikipedia.org/wiki/Edward_Drinker_Cope Edward Drinker Cope]] has lasted until today, with another similar animal from the same habitat named ''Drinker nisti'' in 1990 out of spite! To complicate the matter, we also have ''[[http://en.wikipedia.org/wiki/Nanosaurus Nanosaurus]]'' and ''[[http://en.wikipedia.org/wiki/Laosaurus Laosaurus]]''. Discovered during Cope’s and Marsh’s “war”, ''Nanosaurus agilis'' ("agile dwarf lizard") was very commonly-portrayed in old textbooks for having detained the record of “the smallest North-American dinosaur” for almost a century... but today it might not even be a valid name. Today, the record pertains to a tiny heterodontosaurid found only in 2009, ''[[UsefulNotes/PrehistoricLifePrimitiveOrnithischians Fruitadens]]''. The very fragmentary ''Laosaurus celer'' ("speedy fossil lizard", described in USA in the same period of ''Nanosaurus'') has been involved in this taxonomic tangle as well, with its remains often found mixed with those of ''Dryosaurus''.

* Finally, let’s not forget the “Mysterious Polar Dino”. In year 1987, just one year after the ankylosaur ''Antarctopelta'', the second Antarctic dinosaur was found, described as a “polar hypsilophodont”; the thing is, it has had an even worse fate than the ankylosaur itself. At least, after 20 years of waiting, the latter ''has'' received a name; the polar "hypsy" ''has yet to wait a formal naming and description'', and sadly seems to be almost forgotten today. Partially compensating, several small bipedal ornithischians have been then discovered in other southern continents, the best-known being ''Leaellynasaura amicagraphica''. It was found in 1989 in Australia along with the single lower jaw of the larger ''[[http://en.wikipedia.org/wiki/Atlascopcosaurus Atlascopcosaurus loadsi]]'', so-called from the Atlas-Copco Corporation that funded its excavation. Today, the most-complete Australian "hypsilophodont" is ''[[http://en.wikipedia.org/wiki/Qantassaurus Qantassaurus]]'' (its name is a homage to Qantas, the LandDownUnder airlines). However, there's another relative discovered in Australia at the start of the XX century, but is known only from a femur: ''[[http://en.wikipedia.org/wiki/Fulgurotherium Fulgurotherium australe]]'' (the "lightening beast of the South"). Its name is odd because recalls more that of a prehistoric mammal (''"[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Uintatherium]]"'', and so on) than that of a dinosaur. About South American discoveries, apart from the enigmatic ''Loncosaurus'' (found as well in the early XX century but described from a single femur mixed with a theropod tooth), there are few non-hadrosaur ornithopods found in the 2000s, the largest one being the 6 m long ''[[http://en.wikipedia.org/wiki/Macrogryphosaurus Macrogryphosaurus]]''. Curiously, one small South American ornithopod described in 1996 [[FollowTheLeader has got]] a feminine name reminescent of ''Leaellynasaura'': ''[[http://en.wikipedia.org/wiki/Gasparinisaura Gasparinisaura]]'' ("Gasparini's lizard"). Since that other small ornithischians around the world have received the suffix "-saura", for example "Bugenasaura" (now regarded as a synonym of ''Thescelosaurus'') and, last example, ''[[http://en.wikipedia.org/wiki/Trinisaura Trinisaura]]'', found in Antarctica in the earliest part of 2013 (this one has immediately received a name). Well, [[TheUnfairSex Unfair Sex]] -related names do fit better for [[AnimalMotifs these graceful “gazelle dinos”]] rather than the badass-looking ([[AnimalMotifs and very masculine]]) ankylosaurs...

* As a whole, non-hadrosaurian ornithopods have been found everywhere, even in Antarctica (as we'll see later). Almost all the main dinosaurian faunas had at least one known ornithopod: even the famous Late Cretaceous islets which were where today is Central Europe. ''Rhabdodon priscus'' was a sort of “dwarf iguanodont”, a primitive spike-less iguanodontian analogue to the earlier ''Dryosaurus'' and ''Tenontosaurus''; it was a late-surviving form which managed to reach the K/T extinction event just thanks to its insulation and absence of competition from the much more evolved hadrosaurs. But wait: some hadrosaurs are ''actually'' known as well from that habitat, such as ''[[UsefulNotes/PrehistoricLifeHadrosaurs Telmatosaurus]]''; only, they too were small and primitive. From the same fauna are the close ''Rhabdodon'' relatives ''Mochlodon'' and ''Zalmoxes''. On the other hand, the 3/4 m long ''Callovosaurus'' found in England comes from a far more ancient period: the Callovian stage of the Middle Jurassic (hence the name). It was one of the most ancient iguanodontians known: once considered a camptosaurid, it's actually more closely related to ''Dryosaurus''. ''Valdosaurus'' ("Weald lizard") was another dryosaurid, also English but Early Cretaceous (like ''Hypsilophodon''); some alleged "Valdosaurus" remains were found in Africa, too. ''Kangnasaurus'' was bigger, and lived in Early Cretaceous South Africa: known from scanty remains, it owes its name from a local Ranch. ''Phyllodon'', ''Alocodon'', ''Taveirosaurus'', and ''Trimucrodon'' from Portugal are known only from teeth, and are thus hard to classify. An even more primitive ornithopod from the same period of ''Callovosaurus'' was the Chinese “hypsilophodont” ''[[http://en.wikipedia.org/wiki/Yandusaurus Yandusaurus]]'', once considered the most basal true ornithopod known to science. It was originally named "Yubasaurus", but since that name was not made official, ''Yandusaurus'' got the precedence. Other “hypsilophodonts" from the same fauna were also too primitive to be real ornithopods. The most scientifically-known is ''[[http://en.wikipedia.org/wiki/Agilisaurus Agilisaurus]]'' ("agile lizard"); others are ''Xiaosaurus'', ''Gongbusaurus'', and former ''Yandusaurus'' species ''Hexinlusaurus''. From Early Cretaceous China comes the enigmatic true-ornithopod ''[[http://en.wikipedia.org/wiki/Jeholosaurus Jeholosaurus]]'' (named after the geological formation it was dug out), whose pointed frontal teeth seem indicating an omnivorous diet.

* ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' is the most well-known among those middle-ways between ''Iguanodon'' and hadrosaurs called “basal hadrosauroids”, and was actually closer to duckbills than to ''Iguanodon'' despite sharing thumbspikes with the latter (though less-developed than the Iguanodon's ones). Unlike true hadrosaurs whose teeth were in number of ''hundreds'' and crammed in "batteries", ''Ouranosaurus'' and the other pre-hadrosaurs had less-numerous teeth placed in one single line on each half-jaw -- the primitive condition of almost all the non-hadrosaur dinosaurs. Among the other possible basal hadrosauroids, other than ''Altirhinus'' (see above) and ''[[http://en.wikipedia.org/wiki/Probactrosaurus Probactrosaurus]]'', are also worth of mention ''Protohadros'' and ''Eolambia'', both discovered in 1998 in the USA. The former was initially considered the earliest hadrosaur (its name just means “the first hadrosaur”); the latter received a similar treatment, initially described as the first ancestor of crested hadrosaurs (''Eolambia'' means "dawn lambeosaurine"). On the other hand, the heavily-built ''[[http://en.wikipedia.org/wiki/Lurdusaurus Lurdusaurus]]'' (informally named "Gravisaurus" before its official description: both names mean "heavy lizard") seems very closely-related to ''Iguanodon'', even though shared its habitat with ''Ouranosaurus'' in North Africa. Interestingly, ''Lurdusaurus'' seems showing adaptations for a semi-aquatic lifestyle, which is unusual for ornithischian dinosaurs. [[note]]This hyp was also made for another ornithischian, the basal ceratopsian ''[[http://en.wikipedia.org/wiki/Koreaceratops Koreaceratops]]'' from [[ExactlyWhatItSaysOnTheTin Korea]]: found only in 2012, its describer believed it was actually a ''marine'' dinosaur![[/note]]

* Since its first discovery made in the first decades of the XIX Century, ''Iguanodon'' remains have been found everywhere from Africa to Mongolia, Europe and North America; ''Series/ChasedByDinosaurs'' added some sorta iguanodons even in South American settings - even though some iguanodontians ''are'' known from South America, they were much smaller. ScienceMarchesOn however, and now many of these ''Iguanodon'' species have been reclassified in other genera, while a formerly distinct iguanodontid genus, "Vectisaurus" from Early Cretaceous England, is now classified within ''Iguanodon''. Several from Europe have been created as an homage to some of the greatest XIX century paleontologists - at the time, dinosaur remains were mainly from ''Iguanodon''s. So we have ''Mantellisaurus atherfieldensis'' from Gideon Mantell (''Iguanodon''’s TropeNamer); formerly "Iguanodon atherfieldensis", it was found in the same coal mine near Bernissart in Belgium in which the 30 or so skeletons of the more robust ''Iguanodon bernissartensis'' have been dug out.[[note]]In the same mine were found the teeth of ''Craspedodon'', a putative iguanodontian which could be an unusually European ceratopsian according to recent research.[[/note]] Then, ''Owenodon'' from Richard Owen (dinosaurs’ TropeNamer), and ''Dollodon'' from Louis Dollo (the guy who described the famous iguanodonts found in the “Dinosaur Mine” in Belgium as erect bipedal beasts. [[note]]However, ''Dollodon'' is very likely the same as ''Mantellisaurus''.[[/note]] Another former ''Iguanodon'' species has been renamed "Huxleysaurus" (after Thomas Henry Huxley, supporter of Darwin's theory of evolution), but this name is unofficial at present. Other Europeans were named for their unique physical characteristics, such as ''Hypselospinus'' ("tall spines") and ''Barilium'' ("heavy hips"). The North American ''Iguanodon lakotaensis'' was renamed ''[[http://en.wikipedia.org/wiki/Dakotadon Dakotadon]]'' after the state it was found in. A similar fate befell another South Dakotan iguanodont: ''Osmakasaurus'', from the same rock unit as ''Dakotadon'', was originally named as a species of ''Camptosaurus''. True camptosaurids include ''Bihariosaurus'' from Romania, ''Draconyx'' from Portugal, and maybe North American ''Theiophytalia''. Finally, the Mongolian specimen "Iguanodon orientalis" has been renamed ''Altirhinus kurzanovi''. As with most former ''Iguanodon'' specimens, ''Altirhinus'' was actually closer to hadrosaurs than to ''Iguanodon''. Indeed its name, “high nose”, was given from its humped nose similar to the duckbill ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Gryposaurus]]''. Interesting that Kron (the villainous ''Iguanodon'' in WesternAnimation/{{Dinosaur}}) has a hump-nose that could mean he’s actually an ''Altirhinus''.

* Since its first discovery made in the first decades of the XIX Century, ''Iguanodon'' remains have been found everywhere from Africa to Mongolia, Europe and North America; ''Series/ChasedByDinosaurs'' added some sorta iguanodons even in South American settings - even though some iguanodontians ''are'' known from South America, they were much smaller. ScienceMarchesOn however, and now many of these ''Iguanodon'' species have been reclassified in other genera (while a formerly distinct iguanodontid genus, "Vectisaurus" from Early Cretaceous England, is now classified within ''Iguanodon''). Several from Europe have been created as an homage to some of the greatest XIX century paleontologists - at the time, dinosaur remains were mainly from ''Iguanodon''s. So we have ''Mantellisaurus atherfieldensis'' from Gideon Mantell (''Iguanodon''’s TropeNamer); formerly "Iguanodon atherfieldensis", it was found in the same coal mine near Bernissart in Belgium in which the 30 or so skeletons of the more robust ''Iguanodon bernissartensis'' have been dug out.[[note]]In the same mine were found the teeth of ''Craspedodon'', a putative iguanodontian which could be an unusually European ceratopsian according to recent research.[[/note]] Then, ''Owenodon'' from Richard Owen (dinosaurs’ TropeNamer), and ''Dollodon'' from Louis Dollo (the guy who described the famous iguanodonts found in the “Dinosaur Mine” in Belgium as erect bipedal beasts. [[note]]However, ''Dollodon'' is very likely the same as ''Mantellisaurus''.[[/note]] Another former ''Iguanodon'' species has been renamed "Huxleysaurus" (after Thomas Henry Huxley, supporter of Darwin's theory of evolution), but this name is unofficial at present. Other Europeans were named for their unique physical characteristics, such as ''Hypselospinus'' ("tall spines") and ''Barilium'' ("heavy hips"). The North American ''Iguanodon lakotaensis'' was renamed ''[[http://en.wikipedia.org/wiki/Dakotadon Dakotadon]]'' after the state it was found in. A similar fate befell another South Dakotan iguanodont: ''Osmakasaurus'', from the same rock unit as ''Dakotadon'', was originally named as a species of ''Camptosaurus''. True camptosaurids include ''Bihariosaurus'' from Romania, ''Draconyx'' from Portugal, and maybe North American ''Theiophytalia''. Finally, the Mongolian specimen "Iguanodon orientalis" has been renamed ''Altirhinus kurzanovi''. As with most former ''Iguanodon'' specimens, ''Altirhinus'' was actually closer to hadrosaurs than to ''Iguanodon''. Indeed its name, “high nose”, was given from its humped nose similar to the duckbill ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Gryposaurus]]''. Interesting that Kron (the villainous ''Iguanodon'' in WesternAnimation/{{Dinosaur}}) has a hump-nose that could mean he’s actually an ''Altirhinus''.

Among non-hadrosaur/non-''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Iguanodon]]'' ornithopods, the ones you've more chances to see in media are: ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Hypsilophodon]]'' (the prototype of the "hypsilophodonts" aka small-slender members of the Group); ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Camptosaurus]]'' & ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Dryosaurus]]'' (the two iconic ornithopods from the Late Jurassic; the former was big and Iguanodon-like, the latter small and Hypsilophodon-like): ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Tenontosaurus]]'' (looking like it's in the middle between an ''Iguanodon'' and a ''Hypsilophodon'', but with a distinctively long tail); and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' (with an evident crest on its back, it's traditionally considered an "iguanodont" but was actually closer to hadrosaurs). Among the other examples, the "iguanodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]'' and the "hypsilophodont" ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Leaellynasaura]]'' (both Australian) [[note]]The latter, according to recent research, could not be a proper ornithopod however.[[/note]] were portrayed in 1999 by ''Series/WalkingWithDinosaurs'', while ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Orodromeus]]'', ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Thescelosaurus]]'', and ''Othnielosaurus'' (all "hypsilophodonts") have had notable ScienceMarchesOn stories.

Among non-hadrosaur/non-''Iguanodon'' ornithopods, the ones you've more chances to see in media are: ''Hypsilophodon'' (the prototype of the "hypsilophodonts" aka small-slender members of the Group); ''Camptosaurus'' & ''Dryosaurus'' (the two iconic ornithopods from the Late Jurassic; the former was big and Iguanodon-like, the latter small and Hypsilophodon-like): ''Tenontosaurus'' (looking like it's in the middle between an ''Iguanodon'' and a ''Hypsilophodon'', but with a distinctively long tail); and ''Ouranosaurus'' (with an evident crest on its back, it's traditionally considered an "iguanodont" but was actually closer to hadrosaurs). Among the other examples, the "iguanodont" ''Muttaburrasaurus'' and the "hypsilophodont" ''Leaellynasaura'' (both Australian) [[note]]The latter, according to recent research, could not be a proper ornithopod however.[[/note]] were portrayed in 1999 by ''Series/WalkingWithDinosaurs'', while ''Orodromeus'', ''Thescelosaurus'', and ''Othnielosaurus'' (all "hypsilophodonts") have had notable ScienceMarchesOn stories.

''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Hypsilophodon]]'' is classically countered against ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Iguanodon]]'', which is the traditional prototype of the the “iguanodonts” (large/heavy non-hadrosaurian ornithopods). [[ScienceMarchesOn Now scientists have found]] “hypsilophodonts” is an artificial assemblage including the most basal ornithopods, while “iguanodonts” now indicates a natural group including not only the most ''Iguanodon''-like animals but also duckbills, pre-duckbills and also some traditional “hypsilophodontians” (see below).

* Since its first discovery made in the first decades of the XIX Century, ''Iguanodon'' remains have been found everywhere from Africa to Mongolia, Europe and North America; ''Series/ChasedByDinosaurs'' added some sorta iguanodons even in South American settings - even though some iguanodontians ''are'' known from South America, they were much smaller. ScienceMarchesOn however, and now many of these ''Iguanodon'' species have been reclassified in other genera (while a formerly distinct iguanodontid genus, "Vectisaurus" from Early Cretaceous England, is now classified within ''Iguanodon''). Several from Europe have been created as an homage to some of the greatest XIX century paleontologists - at the time, dinosaur remains were mainly from ''Iguanodon''s. So we have ''Mantellisaurus atherfieldensis'' from Gideon Mantell (''Iguanodon''’s TropeNamer); formerly "Iguanodon atherfieldensis", it was found in the same coal mine near Bernissart in Belgium in which the 30 or so skeletons of the more robust ''Iguanodon bernissartensis'' have been dug out.[[note]]In the same mine were found the teeth of ''Craspedodon'', a putative iguanodontian which could be an unusually European ceratopsian according to recent research.[[/note]] Then, ''Owenodon'' from Richard Owen (dinosaurs’ TropeNamer), and ''Dollodon'' from Louis Dollo (the guy who described the famous iguanodonts found in the “Dinosaur Mine” in Belgium as erect bipedal beasts. [[note]]However, ''Dollodon'' is very likely the same as ''Mantellisaurus''.[[/note]] Another former ''Iguanodon'' species has been renamed "Huxleysaurus" (after Thomas Henry Huxley, supporter of Darwin's theory of evolution), but this name is unofficial at present. Other Europeans were named for their unique physical characteristics, such as ''Hypselospinus'' ("tall spines") and ''Barilium'' ("heavy hips"). The North American ''Iguanodon lakotaensis'' was renamed ''[[http://en.wikipedia.org/wiki/Dakotadon Dakotadon]]'' after the state it was found in. A similar fate befell another South Dakotan iguanodont: ''Osmakasaurus'', from the same rock unit as ''Dakotadon'', was originally named as a species of ''Camptosaurus''. True camptosaurids include ''Bihariosaurus'' from Romania, ''Draconyx'' from Portugal, and maybe North American ''Theiophytalia''. Finally, the Mongolian specimen "Iguanodon orientalis" has been renamed ''Altirhinus kurzanovi''. As with most former ''Iguanodon'' specimens, ''Altirhinus'' was actually closer to hadrosaurs than to ''Iguanodon''. Indeed its name, “high nose”, was given from its humped nose similar to the duckbill ''[[UsefulNotes/PrehistoricLifeHadrosaurs Gryposaurus]]''. Interesting that Kron (the villainous ''Iguanodon'' in WesternAnimation/{{Dinosaur}}) has a hump-nose that could mean he’s actually an ''Altirhinus''.

* ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Ouranosaurus]]'' is the most well-known among those middle-ways between ''Iguanodon'' and hadrosaurs called “basal hadrosauroids”, and was actually closer to duckbills than to ''Iguanodon'' despite sharing thumbspikes with the latter (though less-developed than the Iguanodon's ones). Unlike true hadrosaurs whose teeth were in number of ''hundreds'' and crammed in "batteries", ''Ouranosaurus'' and the other pre-hadrosaurs had less-numerous teeth placed in one single line on each half-jaw -- the primitive condition of almost all the non-hadrosaur dinosaurs. Among the other possible basal hadrosauroids, other than ''Altirhinus'' (see above) and ''Probactrosaurus'' (see in the [[UsefulNotes/PrehistoricLifeHadrosaurs hadrosaur page]]), are also worth of mention ''Protohadros'' and ''Eolambia'', both discovered in 1998 in the USA. The former was initially considered the earliest hadrosaur (its name just means “the first hadrosaur”); the latter received a similar treatment, initially described as the first ancestor of crested hadrosaurs (''Eolambia'' means "dawn lambeosaurine"). On the other hand, the heavily-built ''[[http://en.wikipedia.org/wiki/Lurdusaurus Lurdusaurus]]'' (informally named "Gravisaurus" before its official description: both names mean "heavy lizard") seems very closely-related to ''Iguanodon'', even though shared its habitat with ''Ouranosaurus'' in North Africa. Interestingly, ''Lurdusaurus'' seems showing adaptations for a semi-aquatic lifestyle, which is unusual for ornithischian dinosaurs. [[note]]This hyp was also made for another ornithischian, the basal ceratopsian ''[[http://en.wikipedia.org/wiki/Koreaceratops Koreaceratops]]'' from [[ExactlyWhatItSaysOnTheTin Korea]]: found only in 2012, its describer believed it was actually a ''marine'' dinosaur![[/note]]

* Finally, let’s not forget the “Mysterious Polar Dino”. In year 1987, just one year after the ankylosaur ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Antarctopelta]]'', the second Antarctic dinosaur was found, described as a “polar hypsilophodont”; the thing is, it has had an even worse fate than the ankylosaur itself. At least, after 20 years of waiting, the latter ''has'' received a name; the polar "hypsy" ''has yet to wait a formal naming and description'', and sadly seems to be almost forgotten today. Partially compensating, several small bipedal ornithischians have been then discovered in other southern continents, the best-known being ''Leaellynasaura amicagraphica''. It was found in 1989 in Australia along with the single lower jaw of the larger ''[[http://en.wikipedia.org/wiki/Atlascopcosaurus Atlascopcosaurus loadsi]]'', so-called from the Atlas-Copco Corporation that funded its excavation. Today, the most-complete Australian "hypsilophodont" is ''[[http://en.wikipedia.org/wiki/Qantassaurus Qantassaurus]]'' (its name is a homage to Qantas, the LandDownUnder airlines). However, there's another relative discovered in Australia at the start of the XX century, but is known only from a femur: ''[[http://en.wikipedia.org/wiki/Fulgurotherium Fulgurotherium australe]]'' (the "lightening beast of the South"). Its name is odd because recalls more that of a prehistoric mammal (''"[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Uintatherium]]"'', and so on) than that of a dinosaur. About South American discoveries, apart from the enigmatic ''Loncosaurus'' (found as well in the early XX century but described from a single femur mixed with a theropod tooth), there are few non-hadrosaur ornithopods found in the 2000s, the largest one being the 6 m long ''[[http://en.wikipedia.org/wiki/Macrogryphosaurus Macrogryphosaurus]]''. Curiously, one small South American ornithopod described in 1996 [[FollowTheLeader has got]] a feminine name reminescent of ''Leaellynasaura'': ''[[http://en.wikipedia.org/wiki/Gasparinisaura Gasparinisaura]]'' ("Gasparini's lizard"). Since that other small ornithischians around the world have received the suffix "-saura", for example "Bugenasaura" (now regarded as a synonym of ''Thescelosaurus'') and, last example, ''[[http://en.wikipedia.org/wiki/Trinisaura Trinisaura]]'', found in Antarctica in the earliest part of 2013 (this one has immediately received a name). Well, [[TheUnfairSex Unfair Sex]] -related names do fit better for [[AnimalMotifs these graceful “gazelle dinos”]] rather than the badass-looking ([[AnimalMotifs and very masculine]]) ankylosaurs...

'''The last Gazelle-dinosaur:''' ''[[http://en.wikipedia.org/wiki/Thescelosaurus Thescelosaurus]]''

* The two most famous "hypsilophodonts", ''Hypsilophodon foxi'' and ''Dryosaurus altus'', lived in Early Cretaceous and Late Jurassic respectively: but Hypsilophodon-like animals existed also in Late Cretaceous, even though they tend to be overshadowed in paleo-art by the spectacular ornithischians of their period (hadrosaurs, ceratopsians, ankylosaurs, and pachycephalosaurs). In North-America, while [[UsefulNotes/PrehistoricLifeHadrosaurs duckbills]] ruled the “wildebeest” role played by the camptosaurs in the Jurassic and by the ''Iguanodon''s in Early Cretaceous, the “gazelle” one was mainly played by ''Thescelosaurus neglectus''. ''Thescelosaurus'' ("marvelous lizard") was 3-4 m long and lived at the extreme end of the Cretaceous, 68-66 mya. Rather similar to ''Dryosaurus'' in appearence, cladistic research have revealed it was not a basal iguanodont unlike the latter. Rather robustly-built if compared with ''Hypsilophodon'', the thescelosaur had some small bony scutes on its back, maybe placed under the skin and not-visible in the living animal. Recently, ''Hypsilophodon'' as well has revealed these osteoderms, which were arguably for defense. ''Thescelosaurus'' is the animal from which the controversial “fossilized heart” comes from, which is almost certainly a fossilization artifact: that is, a piece of stone found in one specimen, which casually resembles a heart. Discovered in year 2000, this stony concretion was celebrated as the proof of “warm-bloodedness” among dinosaurs, because it seemingly showed a four-chambered heart just like bird and mammals and unlike most modern reptiles -- crocodilians have four-chambered hearts, but their ancestors could have been warm-blooded as hypothized in the late 2000s. ''Thescelosaurus'' was one of the very few dinosaurs that managed to see the [[RockFallsEveryoneDies asteroid]] at the end of the Dinosaur Era, just like TyrannosaurusRex and ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Triceratops]]''.

'''Hypsilophodont nests?:''' ''[[http://en.wikipedia.org/wiki/Orodromeus Orodromeus]]'' & ''[[http://en.wikipedia.org/wiki/Parksosaurus Parksosaurus]]''

* Other than ''Thescelosaurus'' there were other “hypsilophodontians” from Late Cretaceous North America that were smaller and lived slightly earlier than it. ''Orodromeus makelai'' ("Makela's runner of the [Egg] Mountain") was discovered in Montana in year 1988 by Jack Horner and his assistant Robert [[ExactlyWhatItSaysOnTheTin Makela]] in the same site in which they had found ''Maiasaura peeblesorum'' eight years before. They noted some small unusually spiral-shaped nests full of eggs containing fossilized embryos, next to the bigger & more famous ''Maiasaura'' ones, which they attributed to ''Orodromeus'': as the bones inside those eggs were already well-formed, they said that the orodromeus' hatchlings were more independent after birth than the maiasaura's ones. ScienceMarchesOn however, and later it was found that those eggs/embryos were from the theropod ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Troodon]]'' instead. The ironical thing is, fossils of troodonts were discovered as well around those putative ''Orodromeus'' nests, but it was thought that they were actually preying on Orodromeus nestlings: an astonishingly similar story to the “Oviraptor robbing Protoceratops' eggs”. Found in 2007, its relative ''[[http://en.wikipedia.org/wiki/Oryctodromeus Oryctodromeus]]'' ("digging runner") lived quite a bit earlier than the [[NamesTheSame similar-named]] ''Orodromeus'' in Middle Cretaceous, but has also shown the first proof of digging behavior among non-avian dinosaurs: its skeleton has been found inside a fossilized burrow. Another relative found in Alberta is known since the start of the XX century: ''Parksosaurus'' ("William Parks' lizard", sometimes misspelled "''Parkosaurus''"). Similar in size and shape to ''Orodromeus'' but living few million years later, it could be actually closer to ''Thescelosaurus'' (which lived even later), and has recently become the namesake of its own family of ornithopods, the Parksosaurids. ''[[http://en.wikipedia.org/wiki/Zephyrosaurus Zephyrosaurus]]'' ("lizard of the western wind"), lived earlier than all these, in the Early Cretaceous Montana: it could have met ''[[UsefulNotes/StockDinosaursSaurischianDinosaurs Deinonychus]]'' in real life, and possibly was one of its preys.

'''Named after a Girl:''' ''[[http://en.wikipedia.org/wiki/Leaellynasaura Leaellynasaura]]''

* If you’ve seen the fifth episode of ''Series/WalkingWithDinosaurs'', you’ll already have the idea what we’re talking about. Dinosaur names are often thought bizarre-sounding, and this animal certainly does match the commonplace very well, like its bigger compatriot ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]''. This one is called from the village of Muttaburra in Queensland, Australia, where its only skeleton was found in 1981; ''Leaellynasaura amicagraphica'' was named after the daughter of its discoverers, Leaellyn [[note]] Another little-known australian dinosaur, ''[[http://en.wikipedia.org/wiki/Timimus Timimus]]'', was named after Leaellyn's brother, Tim. It has ''mimus'' at the end because was originally thought an ornithomimosaur.[[/note]] -- hence its feminine suffix ''saura'' - just like the hadrosaur ''Maiasaura'' which means “good-mother lizard”. Together with the shorter-named but equally bizarre-sounding ankylosaur ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Minmi]]'', these are the most well-known Aussie Dinos. Similar but smaller than ''Iguanodon'' and still completely bipedal like the most basal ornithopods, ''Muttaburrasaurus'' is easy to tell apart from its relatives thanks to its prominent nose, similar to other more evolved ornithopods but more bulbous. We don't know if it had thumbspikes: being more basal than the almost-spikeless ''Camptosaurus'' and more closely related to the rhabdodonts (see below), this is unlikely, but it is traditionally shown with them in drawings. First-found in 1989, ''Leaellynasaura'' was a small (1 m long) bipedal animal similar to ''Hypsilophodon''. Once considered an “hypsilophodontian”, even its ornithopod status is disputed today, and is now generally regarded as a more basal ornithischian. The fossil material attributed to ''Leaellynasaura'' [[http://espace.library.uq.edu.au/view/UQ:320937 is currently being revised]], and until that revision is finished and published there is not much that can be said with certainty about this particular dinosaur. Fossils discovered in Australia in the 2000s indicate presence of a small Early Cretaceous ornithischian with tail 3 times longer that its own body (even more than the ''Tenontosaurus'' tail); whether this is the same taxon as ''Leaellynasaura'' or not remains to be seen. The discover of ''Muttaburrasaurus'', ''Minmi'', and ''Leaellynasaura'' in the 1980s made sensation in Australia, because very few dinosaurs were known before in the LandDownUnder, all fragmentary. ''Muttaburrasaurus'', like ''Minmi'', still is one of the most complete dinosaurs found there; ''Leaellynasaura'' ‘s skeletons are more incomplete, but the latter's importance was due to having contributed to enforce the “warm-blooded dinosaurs” hypothesis even more. In Early Cretaceous, Australia was not the temperate/tropical/desertic country we know today, but a colder world with warm summers but cold winters - because was much closer to the South Pole. How could such a small, clearly non-migratory animal like this manage to survive that icy winter? The only explanation was: ''Leaellynasaura'' was warm-blooded. Furthermore, its unusually big eyes could have been used to see throughout the darkness of the polar winter. All these arguments have been discussed in ''Series/WalkingWithDinosaurs'', in which a family of ''Leaellynasaura'' makes the main characters. The show also portrayed ''Muttaburrasaurus'', as a migrating animal that flees the winter in herd like caribous; it also added to it speculative nasal sacs to make loud sounds (like what's been hypothized for some hadrosaurs), but we don't have direct evidence for this.

----

'''A never-ending rivarly:''' ''[[http://en.wikipedia.org/wiki/Othnielosaurus Othnielosaurus]]'' & ''[[http://en.wikipedia.org/wiki/Drinker_(dinosaur) Drinker]]''

* Travelling even further back, in Late Jurassic USA, other than ''[[UsefulNotes/StockDinosaursTrueDinosaurs Camptosaurus]]'' the Wildebeest and ''[[UsefulNotes/StockDinosaursTrueDinosaurs Dryosaurus]]'' the Gazelle we'd encounter also ''Othnielosaurus'' the Dik-Dik. This was indeed a very small animal, 1.5 m long (smaller than an ''Hypsilophodon''), with a very convoluted ScienceMarchesOn story. It was described in 1977 as ''[[http://en.wikipedia.org/wiki/Othnielia Othnielia rex]]'' ("Othnielia" is the name usually heard in docu-media), and renamed more recently because its type material was not diagnostic. Both curious names derive from [[http://en.wikipedia.org/wiki/Othniel_Charles_Marsh Othniel Charles Marsh]], one of the two scientists who “fought” the Bone-Wars in the XIX century. As it seems, its notorious rivalry with [[http://en.wikipedia.org/wiki/Edward_Drinker_Cope Edward Drinker Cope]] has lasted until today, with another similar animal from the same habitat named ''Drinker nisti'' in 1990 out of spite! To complicate the matter, we also have ''[[http://en.wikipedia.org/wiki/Nanosaurus Nanosaurus]]'' and ''[[http://en.wikipedia.org/wiki/Laosaurus Laosaurus]]''. Discovered during Cope’s and Marsh’s “war”, ''Nanosaurus agilis'' ("agile dwarf lizard") was very commonly-portrayed in old textbooks for having detained the record of “the smallest North-American dinosaur” for almost a century... but today it might not even be a valid name. Today, the record pertains to a tiny heterodontosaurid found only in 2009, ''[[UsefulNotes/PrehistoricLifePrimitiveOrnithischians Fruitadens]]''. The very fragmentary ''Laosaurus celer'' ("speedy fossil lizard", described in USA in the same period of ''Nanosaurus'') has been involved in this taxonomic tangle as well, with its remains often found mixed with those of ''Dryosaurus''.

----

'''Icy amnesia:''' The "Antarctic hypsilophodont"

* Finally, let’s not forget the “Mysterious Polar Dino”. In year 1987, just one year after the ankylosaur ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Antarctopelta]]'', the second Antarctic dinosaur was found, described as a “polar hypsilophodont”; the thing is, it has had an even worse fate than the ankylosaur itself. At least, after 20 years of waiting, the latter ''has'' received a name; the polar "hypsy" ''has yet to wait a formal naming and description'', and sadly seems to be almost forgotten today. Partially compensating, several small bipedal ornithischians have been then discovered in other southern continents, the best-known being ''Leaellynasaura amicagraphica''. It was found in 1989 in Australia along with the single lower jaw of the larger ''[[http://en.wikipedia.org/wiki/Atlascopcosaurus Atlascopcosaurus loadsi]]'', so-called from the Atlas-Copco Corporation that funded its excavation. Today, the most-complete Australian "hypsilophodont" is ''[[http://en.wikipedia.org/wiki/Qantassaurus Qantassaurus]]'' (its name is a homage to Qantas, the LandDownUnder airlines). However, there's another relative discovered in Australia at the start of the XX century, but is known only from a femur: ''[[http://en.wikipedia.org/wiki/Fulgurotherium Fulgurotherium australe]]'' (the "lightening beast of the South"). Its name is odd because recalls more that of a prehistoric mammal (''"[[UsefulNotes/StockDinosaursNonDinosaurs Megatherium]]"'', ''"[[UsefulNotes/StockDinosaursNonDinosaurs Uintatherium]]"'', and so on) than that of a dinosaur. About South American discoveries, apart from the enigmatic ''Loncosaurus'' (found as well in the early XX century but described from a single femur mixed with a theropod tooth), there are few non-hadrosaur ornithopods found in the 2000s, the largest one being the 6 m long ''[[http://en.wikipedia.org/wiki/Macrogryphosaurus Macrogryphosaurus]]''. Curiously, one small South American ornithopod described in 1996 [[FollowTheLeader has got]] a feminine name reminescent of ''Leaellynasaura'': ''[[http://en.wikipedia.org/wiki/Gasparinisaura Gasparinisaura]]'' ("Gasparini's lizard"). Since that other small ornithischians around the world have received the suffix "-saura", for example "Bugenasaura" (now regarded as a synonym of ''Thescelosaurus'') and, last example, ''[[http://en.wikipedia.org/wiki/Trinisaura Trinisaura]]'', found in Antarctica in the earliest part of 2013 (this one has immediately received a name). Well, [[TheUnfairSex Unfair Sex]] -related names do fit better for [[AnimalMotifs these graceful “gazelle dinos”]] rather than the badass-looking ([[AnimalMotifs and very masculine]]) ankylosaurs...

----

* Since its first discovery made in the first decades of the XIX Century, ''Iguanodon'' remains have been found everywhere from Africa to Mongolia, Europe and North America; ''Series/ChasedByDinosaurs'' added some sorta iguanodons even in South American settings - even though some iguanodontians ''are'' known from South America, they were much smaller. ScienceMarchesOn however, and now many of these ''Iguanodon'' species have been reclassified in other genera (while a formerly distinct iguanodontid genus, "Vectisaurus" from Early Cretaceous England, is now classified within ''Iguanodon''). Several from Europe have been created as an homage to some of the greatest XIX century paleontologists - at the time, dinosaur remains were mainly from ''Iguanodon''s. So we have ''Mantellisaurus atherfieldensis'' from Gideon Mantell (''Iguanodon''’s TropeNamer); formerly "Iguanodon atherfieldensis", it was found in the same coal mine near Bernissart in Belgium in which the 30 or so skeletons of the more robust ''Iguanodon bernissartensis'' have been dug out.[[note]]In the same mine were found the teeth of ''Craspedodon'', a putative iguanodontian which could be an unusually European ceratopsian according to recent research.[[/note]] Then, ''Owenodon'' from Richard Owen (dinosaurs’ TropeNamer), and ''Dollodon'' from Louis Dollo (the guy who described the famous iguanodonts found in the “Dinosaur Mine” in Belgium as erect bipedal beasts. [[note]]However, ''Dollodon'' is very likely the same as ''Mantellisaurus''.[[/note]] Another former ''Iguanodon'' species has been renamed "Huxleysaurus" (after Thomas Henry Huxley, supporter of Darwin's theory of evolution), but this name is unofficial at present. Other Europeans were named for their unique physical characteristics, such as ''Hypselospinus'' ("tall spines") and ''Barilium'' ("heavy hips"). The North American ''Iguanodon lakotaensis'' was renamed ''[[http://en.wikipedia.org/wiki/Dakotadon Dakotadon]]'' after the state it was found in. A similar fate befell another South Dakotan iguanodont: ''Osmakasaurus'', from the same rock unit as ''Dakotadon'', was originally named as a species of ''Camptosaurus''. True camptosaurids include ''Bihariosaurus'' from Romania, ''Draconyx'' from Portugal, and maybe North American ''Theiophytalia''. Finally, the Mongolian specimen "Iguanodon orientalis" has been renamed ''Altirhinus kurzanovi''. As with most former ''Iguanodon'' specimens, ''Altirhinus'' was actually closer to hadrosaurs than to ''Iguanodon''. Indeed its name, “high nose”, was given from its humped nose similar to the duckbill ''[[UsefulNotes/PrehistoricLifeHadrosaurs Gryposaurus]]''. Interesting that Kron (the villainous ''Iguanodon'' in Disney/{{Dinosaur}}) has a hump-nose that could mean he’s actually an ''Altirhinus''.

* If you’ve seen the fifth episode of ''Series/WalkingWithDinosaurs'', you’ll already have the idea what we’re talking about. Dinosaur names are often thought bizarre-sounding, and this animal certainly does match the commonplace very well, like its bigger compatriot ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]''. This one is called from the village of Muttaburra in Queensland, Australia, where its only skeleton was found in 1981; ''Leaellynasaura amicagraphica'' was named after the daughter of its discoverers, Leaellyn [[note]] Another little-known australian dinosaur, ''[[http://en.wikipedia.org/wiki/Timimus Timimus]]'', was named after Leaellyn's brother, Tim. It has ''mimus'' at the end because was originally thought an ornithomimosaur.[[/note]] -- hence its feminine suffix ''saura'' - just like the hadrosaur ''Maiasaura'' which means “good-mother lizard”. Together with the shorter-named but equally bizarre-sounding ankylosaur ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Minmi paravertebra]]'', these are the most well-known Aussie Dinos. Similar but smaller than ''Iguanodon'' and still completely bipedal like the most basal ornithopods, ''Muttaburrasaurus'' is easy to tell apart from its relatives thanks to its prominent nose, similar to other more evolved ornithopods but more bulbous. We don't know if it had thumbspikes: being more basal than the almost-spikeless ''Camptosaurus'' and more closely related to the rhabdodonts (see below), this is unlikely, but it is traditionally shown with them in drawings. First-found in 1989, ''Leaellynasaura'' was a small (1 m long) bipedal animal similar to ''Hypsilophodon''. Once considered an “hypsilophodontian”, even its ornithopod status is disputed today, and is now generally regarded as a more basal ornithischian. The fossil material attributed to ''Leaellynasaura'' [[http://espace.library.uq.edu.au/view/UQ:320937 is currently being revised]], and until that revision is finished and published there is not much that can be said with certainty about this particular dinosaur. Fossils discovered in Australia in the 2000s indicate presence of a small Early Cretaceous ornithischian with tail 3 times longer that its own body (even more than the ''Tenontosaurus'' tail); whether this is the same taxon as ''Leaellynasaura'' or not remains to be seen. The discover of ''Muttaburrasaurus'', ''Minmi'', and ''Leaellynasaura'' in the 1980s made sensation in Australia, because very few dinosaurs were known before in the LandDownUnder, all fragmentary. ''Muttaburrasaurus'', like ''Minmi'', still is one of the most complete dinosaurs found there; ''Leaellynasaura'' ‘s skeletons are more incomplete, but the latter's importance was due to having contributed to enforce the “warm-blooded dinosaurs” hypothesis even more. In Early Cretaceous, Australia was not the temperate/tropical/desertic country we know today, but a colder world with warm summers but cold winters - because was much closer to the South Pole. How could such a small, clearly non-migratory animal like this manage to survive that icy winter? The only explanation was: ''Leaellynasaura'' was warm-blooded. Furthermore, its unusually big eyes could have been used to see throughout the darkness of the polar winter. All these arguments have been discussed in ''Series/WalkingWithDinosaurs'', in which a family of ''Leaellynasaura'' makes the main characters. The show also portrayed ''Muttaburrasaurus'', as a migrating animal that flees the winter in herd like caribous; it also added to it speculative nasal sacs to make loud sounds (like what's been hypothized for some hadrosaurs), but we don't have direct evidence for this.

* If you’ve seen the fifth episode of ''Series/WalkingWithDinosaurs'', you’ll already have the idea what we’re talking about. Dinosaur names are often thought bizarre-sounding, and this animal certainly does match the commonplace very well, like its bigger compatriot ''[[UsefulNotes/StockDinosaursOrnithischianDinosaurs Muttaburrasaurus]]''. This one is called from the village of Muttaburra in Queensland, Australia, where its only skeleton was found in 1981; ''Leaellynasaura'' was named after the daughter of its discoverers, Leaellyn [[note]] Another little-known australian dinosaur, ''[[http://en.wikipedia.org/wiki/Timimus Timimus]]'', was named after Leaellyn's brother, Tim. It has ''mimus'' at the end because was originally thought an ornithomimosaur.[[/note]] -- hence its feminine suffix ''saura'' - just like the hadrosaur ''Maiasaura'' which means “good-mother lizard”. Together with the shorter-named but equally bizarre-sounding ankylosaur ''[[UsefulNotes/PrehistoricLifeAnkylosaurs Minmi paravertebra]]'', these are the most well-known Aussie Dinos. Similar but smaller than ''Iguanodon'' and still completely bipedal like the most basal ornithopods, ''Muttaburrasaurus'' is easy to tell apart from its relatives thanks to its prominent nose, similar to other more evolved ornithopods but more bulbous. We don't know if it had thumbspikes: being more basal than the almost-spikeless ''Camptosaurus'' and more closely related to the rhabdodonts (see below), this is unlikely, but it is traditionally shown with them in drawings. First-found in 1989, ''Leaellynasaura'' was a small (1 m long) bipedal animal similar to ''Hypsilophodon''. Once considered an “hypsilophodontian”, even its ornithopod status is disputed today, and is now generally regarded as a more basal ornithischian. The fossil material attributed to ''Leaellynasaura'' [[http://espace.library.uq.edu.au/view/UQ:320937 is currently being revised]], and until that revision is finished and published there is not much that can be said with certainty about this particular dinosaur. Fossils discovered in Australia in the 2000s indicate presence of a small Early Cretaceous ornithischian with tail 3 times longer that its own body (even more than the ''Tenontosaurus'' tail); whether this is the same taxon as ''Leaellynasaura'' or not remains to be seen. The discover of ''Muttaburrasaurus'', ''Minmi'', and ''Leaellynasaura'' in the 1980s made sensation in Australia, because very few dinosaurs were known before in the LandDownUnder, all fragmentary. ''Muttaburrasaurus'', like ''Minmi'', still is one of the most complete dinosaurs found there; ''Leaellynasaura'' ‘s skeletons are more incomplete, but the latter's importance was due to having contributed to enforce the “warm-blooded dinosaurs” hypothesis even more. In Early Cretaceous, Australia was not the temperate/tropical/desertic country we know today, but a colder world with warm summers but cold winters - because was much closer to the South Pole. How could such a small, clearly non-migratory animal like this manage to survive that icy winter? The only explanation was: ''Leaellynasaura'' was warm-blooded. Furthermore, its unusually big eyes could have been used to see throughout the darkness of the polar winter. All these arguments have been discussed in ''Series/WalkingWithDinosaurs'', in which a family of ''Leaellynasaura'' makes the main characters. The show also portrayed ''Muttaburrasaurus'', as a migrating animal that flees the winter in herd like caribous; it also added to it speculative nasal sacs to make loud sounds (like what's been hypothized for some hadrosaurs), but we don't have direct evidence for this.

'''Named after a little Girl:''' ''[[http://en.wikipedia.org/wiki/Leaellynasaura Leaellynasaura]]''