Prehistoric Life/Dinosaurs/Birdlike Theropods: Difference between revisions

{{tropeUseful Notes}}

* [[Raptor Attack]] exhaustively talks about dromaeosaurids. We’ll talk more about their namesake ''Dromaeosaurus'', and other non-stock relatives. The very first discovered dromaeosaurid (1920s), ''Dromaeosaurus'' has an unexpectedly generic meaning: just “running lizard”. This because its sickle claws were missing in its original skeleton, and scientists believed it was a generic type of small theropod. The image of a [[Hook Hand|hook-footed]] dinosaur came to light only after the description of ''Deinonychus'' in the sixties.<br />The same size of ''[[Stock Dinosaurs|Velociraptor]]'' but with a shorter head and stronger jaws and teeth, ''Dromaeosaurus'' is less-frequently portrayed than the [[Power Trio]] made up of ''Utahraptor'', ''Velociraptor'', and ''Deinonychus''. Despite this, ''Dromaeosaurus'' appears regularly in dino-books and has also made some apparitions in TV documentaries. If you see a dromeosaurid interacting with ''[[Tyrannosaurus Rex]]'' or ''Triceratops'' in Late Cretaceous North America, it would be ''Dromaeosaurus'' <ref>To be correct, however, ''Dromaeosaurus'' lived some million years before the end of the Cretaceous in which ''T. rex'' and ''Triceratops'' lived, but some fragmentary remains might suggest it reached even the last bit of the Mesozoic.</ref> -- unless the writers [[Did Not Do the Research]] or [[They Just Didn't Care]]: some docus have shown ''Deinonychus'' in this role. ''[[Walking Withwith Dinosaurs]]'' dealed with the problem in a bizarre way: here, the dromeosaurids are officially ''Dromaeosaurus''… but ''have the shape of Deinonychus''. Actually, every dromeosaurid in the original series was a ''Deinonychus'', ''Utahraptor'' included -- which, even though their name clearly means “Utah thief”, were portrayed [[Misplaced Wildlife|living in Europe]] [[They Just Didn't Care|for some reason]]. And to make the “utahraptors” and the “dromeosauruses” distinguishable, they show up [[Palette Swap|with a different coloration]].<br />In this show, ''Utahraptor''s are also portrayed in the way dromeosaurids were once represented in paleo-art: naked-skinned, [[Panthera Awesome|colored like big cats]], chasing an iguanodont [[Zerg Rush|in pack]], jumping on it using their sickle-claws as spurs, and eventually killing it with (a quite exaggerated) ease. Many dino-books have made this thing [[Up to Eleven]] with ''Dromaeosaurus'', depicting scenes in which these turkey-sized predators chase in packs ''adult ''Edmontosaurus'' and ''Triceratops'' 500 times heavier'', and ''disemboweling them with their sickle-claws''. [[Science Marches On|Current paleontology]] suggests that ''Dromaeosaurus'' and the other “raptors” hunted small prey and only ate the carcasses of the giant herbivores. But stop now.<br />''Dromaeosaurus'', ''Velociraptor'', ''Deinonychus'' and ''Utahraptor'', together with some other genera, used to make ''the'' dromaeosaurids before the ''[[Jurassic Park]]'' times and also few years later (middle 1990s). We now know they actually ''[[Science Marches On|do not match ]]'' [[Small Taxonomy Pools|the great variety within their family]]. Especially since the beginning of the 2000s, mny new dromaeosaur species have been discovered, most of them [[Sure Why Not|having received the suffix raptor]]. Examples are the North-American ''Bambiraptor'' (so called because its skeleton [[Bambi (Disney)|was from a juvenile]]); the European ''Pyroraptor''; and the South American, short-armed ''Austroraptor''. One exception is ''Achillobator'', which lived in Late Cretaceous Mongolia and, with its 6 m long body, was only slightly smaller than ''Utahraptor'' from [[Exactly What It Says Onon the Tin|Utah]]. These were all ground-dwelling kinds with a running-plan like the traditionally-intended “raptors”.<br />But other “new” dromeosaurids have turned out to be smaller, more specialized animals often with some tree-climbing adaptations. Because of their apparently non-raptor-like nature, some of them were not even initially thought to be dromaeosaurs: this explains why they haven’t got the suffix –raptor. The tiny ''Rahonavis'' from Madagascar was initially thought to be some sort of ''bird''. The same about ''Unenlagia'', the first dromaeosaurid discovered in South America. Another non-raptor-looking dromaeosaur found in 2000 (in spite of being a climbing kind it ends in –raptor nonetheless), is now one of the most portrayed bird-like dinosaurs: obviously, we’re talking about ''Microraptor''. See also the “Liaoning Coelurosaurs” entry below.

* ''[[Stock Dinosaurs|Oviraptor]]'' had many relatives. Most of them have been found since the 1990s in Cretaceous Asia, but one from in North America has also been known since the 1910s: ''Chirostenotes'', to this day still one of the few North-American oviraptorosaurs. Despite this “privileged” position, ''Chirostenotes'' remains a rather obscure dinosaur, and has had a convoluted [[Science Marches On]]-story. Since its first skeleton lacked the skull, was initially classified a “generic toothed coelurosaur”. Its toothless skull was found in 1940, but was named ''Caenagnathus'' and believed to be a bird. In the 1980s, scientists decided that ''Caenagnathus'' and ''Chirostenotes'' were one and the same, and “''Caenagnathus''” fell in disuse, having been created after the other name.<br />But in recent years, someone has again made these genera distinct. Since the skull showed only a small relief on the nose, ''Chirostenotes'' was shown almost-crestless in old portraits; but the skull was incomplete, and now is thought it had a large crest similar to that of ''Citipati'': that is, the animal which people usually think of when they think “''Oviraptor''”. Indeed, most alleged “''Oviraptor''” remains have been reclassified into other genera: among these the famous “dinosaur on its nest” found in the 1990s, which also contributed to debunk the classic “egg-robbing specialist” reputation.<br />As a whole, oviraptorosaurs were quite similar to each other, but their skull ornamentations were more varied, and only the "most evolved" species were toothless and had the well-known cassowary-like crest. The oviraptorosaurs' way of life still remains an enigma: today most scientists think they were omnivorous animals that ate berries as well as insects (flowering plants were already diverse in the Cretaceous); this however doesn't exclude that they occasionally ate some unattended eggs if they got the chance: their short strong jaws and agile hands are, after all, well-suited for this –- many modern mammalian carnivores, though mainly [[Exactly What It Says Onon the Tin|carnivorous]], also eat eggs if they have the chance. Some other primitive oviraptorosaurs are listed below: among them, several are known from feathered fossils from Liaoning.

* When did the Great Feather Adventure begin? The answer: in 1980, in the Mongolian Gobi Desert, the same place where ''Oviraptor'' and ''Velociraptor'' were first discovered. That year, a new kind of Late Cretaceous “coelurosaur” was described from a partial skeleton, which astonished the scientist who found it. He chose to name his find ''Avimimus'' - “bird mimic”, the same as ''Ornithomimus'', only with a Latin prefix instead of Greek. Despite this, ''Avimimus'' was not an ornithomimid, but an only 5 ft long, late-surviving basal oviraptorosaur. Nothing special per-se… except for one thing: it was the ''very first'' dinosaur whose skeleton showed some evidence of feathers. Not prints on the rock however, only a crest on its arm-bones that resembled that of modern birds. For about 15 years since then, ''Avimimus'' has been the ''only'' non-avian dinosaur regularly portrayed with feathers – often in an incorrect way: certain depictions showed it as a short-winged ''Archaeopteryx'' with the same head-shape, jaws filled with teeth, and splayed forelimbs, as if was about to take off.<br />It actually had a short head and short arms typical of oviraptorousars, so it couldn’t fly. However, it should be noted that ''Avimimus'' lacked an oviraptorian crest, and also had serrations in its beak which could have worked as teeth. Since the end of the 1990s, more and more new feathered dinosaurs fossils were found in China, making ''Avimimus'' ‘s relevance mainly historical at this point.

* The first unequivocal non-avian dinosaur fossils with actual feathers preserved came to light in the second half of the 1990s in Liaoning (province of China). They were extraordinarily well-preserved, better than almost any other known dinosaur fossil; they were all small-sized (the biggest was only 8 ft long); they hailed mostly from the Early Cretaceous (unlike ''Avimimus''); and they represented almost all of the main coelurosaur subgroups, giving a sort of snapshot of the coelurosaurian fauna of the time. More than 20 genera have been described so far, and others could still join them in the future: we’ll mention only some examples.<br />''Sinosauropteryx'' (“Chinese feathered lizard”) was the first to be discovered (1996); a compsognathid, it was the very first non-avian dinosaur to have shown prints of feathers; being it was a non-maniraptoran coelurosaur, these were still down-like, unlike modern feathers. The very first Liaoning coelurosaurs, discovered with vaned feathers in 1997 and 1998, were much closer to birds: these were ''Protarchaeopteryx'' (“First Archaeopteryx”) and ''Caudipteryx'' (“feathered tail”). Both were basal oviraptorosaurs similar to ''Avimimus'', but only 2-3 ft long and with teeth; they had pennaceous feathers on their forearms and their tail feathers were homologous to those of the famous ''[[Stock Dinosaurs|Archaeopteryx]]'' (not casually, these three dinosaurs have been named with the suffix -pteryx).<br />However, the wing-feathers of ''Caudipteryx'' and ''Protarchaeopteryx'' were short and symmetrical, unlike those of true birds, and thus totally unsuitable for flight. Soon after, the list of feathered dinosaur fossils increased dramatically each year. The herbivorous ''Beipiaosaurus'' is perhaps the most specialized among them, being a small therizinosaur (see at the bottom of the page) with a down-like covering and some thin feathers on its forearm. In 2004, ''even a feathered tyrannosauroid'' was discovered: ''Dilong'', a slender coelurosaur with little external resemblance to a ''T. rex'', preserving some down-like feathers.<br />Other Liaoning coelurosaurs showed up in the third episode "Dino-Birds" of the miniseries ''[[Prehistoric Park]]''. The chosen ones were: the buck-toothed oviraptorosaur ''Incisivosaurus'' because of its [[Rule of Funny|funny look]], the troodontid ''Mei'', which is now “the shortest-named dino” along with the alvarezsaurid ''Kol'' (the former record-holders were the Australian ankylosaur ''Minmi'' and the oviraptorosaur ''Khaan''), and, naturally, the ever-present ''Microraptor'' (see below).<ref> Note, however, that fossils of ''Incisivosaurus'' and ''Mei'' have not yet been found preserving soft tissues, unlike the other dinosaurs listed here. Nonetheless, being maniraptors, they almost certainly had feathers. Also, ''Microraptor'' is in fact known from a younger formation than the other dinosaurs mentioned here.</ref> In “Dino-Birds”, Nigel Marven makes a [[Time Travel]] to the Cretaceous China to save some ''Microraptor''s from extinction; before ending the mission, he encounters several ''Mei'' (referred to by their whole scientific name: ''Mei long'') apparently sleeping in the same bird-like position in which the type specimen was found fossilized (they were actually dead), while the other ''Mei long'' act as the “danger of the forest”, and to fit their fearsome better role, are [[Rule of Cool|oversized]] [[Somewhere a Paleontologist Is Crying|and lack feathers]].<br />Returning to [[Real Life]], the most extraordinary Liaoning discovery has come in 2009 from Jurassic rocks: ''[[wikipedia:Anchiornis|Anchiornis]]'' (literally “near bird”). This pigeon-sized troodontid (once the smallest non-avian dinosaur known, but now usurped of this record by a fragmentary tiny indeterminate maniraptor from Britain) has, amazingly, preserved not only its whole plumage, but ''even the original colors''. Since colors have almost never preserved in vertebrate fossil record, it’s easy to understand the extraordinariness of such a discovery. Even the aforementioned ''[[wikipedia:Sinosauropteryx#Colouration|Sinosauropteryx]]'' has left some traces of color, as did probably other feathered dinosaur fossils, such as the basal bird ''[[Useful Notes/Prehistoric Life /Other Extinct Creatures|Confuciusornis]]'' and the dromaeosaurid ''Sinornithosaurus''. Still, ''Anchiornis'' remains the most well-preserved, and it is the only non-avian dinosaur whose precise appearance is known with a reasonable degree of sureness.<br />''However'', since fossilization processes often change the original patterns of live animals, the ''true'' colors of ''Anchiornis'' could possibly have faded or even changed a fair bit in 160 million years. We may never know how close our restorations are.

:If this is true, it would mean that flight evolved ''before'' the appearance of the so-called “first-bird”, because ''Microraptor'' was less close to modern birds than ''Archaeopteryx'' was. And since flight was achieved in basal dromaeosaurids, this would mean that… yes, ''Velociraptor'' and all other dromaeosaurids may have descended from ''flying'' ancestors! One scientist did go [[Up to Eleven]] declaring that ''all'' maniraptorans descended from flying ancestors: this would mean, ''Troodon'', ''Oviraptor'', and even the huge ''Therizinosaurus'' were ancestrally '''[[Giant Flyer|creatures of the air]]''', which, like ostriches or rheas, returned to a more ground-level way of life and increased their size.<br />Whatever the case was in [[Real Life]], ''Microraptor'' immediately became the center of much interest soon after the year 2000, becoming rapidly popular in illustrated books (also because was the considered the smallest dinosaur at the time); it became even more widely-known after being portrayed as one of the main animal characters in the aforementioned ''[[Prehistoric Park]]'' (where it was portrayed with the classic, splayed-limbs gliding style, now known to be anatomically impossible). Soon afterwards, it started to gain attention by the broader pop-cultural world, and it could at this point be qualified as a true [[Stock Dinosaurs|Stock Dinosaur]] (even if only in the Rarely-Seen section).<br />There is another story to be told about ''Microraptor''. Before being discovered properly, the tail of one specimen had been mixed with the front end of a true bird found in Liaoning, ''[[Useful Notes/Prehistoric Life /Other Extinct Creatures|Yanornis]]''; the so-created [[Mix and Match Critter]] was published in media as a new kind of bird-dinosaur, “''Archaeoraptor''”, but this hoax was exposed after qualified scientists studied the specimen -- in fact the world-''in''famous article that published the fake was so hastily put-together, they didn't even ''bother'' to check if it was a true fossil or not... leading to one of the biggest controversies of modern paleontology. But although “''Archaeoraptor''” itself didn't exist, its tail belonged to a real animal, one that redefined our understanding of dinosaurs even more than an actual “''Archaeoraptor''” would have. This is an often overlooked detail, especially by creationists and conspiracy theorists who still can't let go of the controversy.

* Lets leave Liaoning behind and go discover another odd-looking bird-like dinosaur, ''Mononykus''. Discovered in 1993 and initially called “''Mononychus''” (but that name was already taken by an insect), this is an enigmatic animal which shared Late Cretaceous Mongolia with ''Avimimus'', ''Velociraptor'', ''Saurornithoides'', ''Oviraptor'' and several other coelurosaurs. Only 3 ft long, its name means “one claw” because of its strange, ''one-fingered'' hands (the other two digits usually present in coelurosaurian hands were simple stubs on ''Mononykus'').<br />We still don't know how ''Mononykus'' could have used its [[Hook Hand|“hooks”]]: maybe it destroyed termite-mounds with them? One close relative, ''Shuvuuia'' (which just means “bird” in Mongolian), was a close relative found in 1999, and lived alongside ''Mononykus''. Unlike the latter, ''Shuvuuia'' has left some cranial remains, which show a mobile upper jaw totally similar to a modern bird's; but this discovery has only made their way of life even more enigmatic.<br />These dinosaurs, along with other relatives, form the Alvarezsaurids, a mainly Cretaceous family named after ''Alvarezsaurus'', a more primitive South American genus discovered incidentally in the same year as Mononykus. It’s significant that ''Alvarezsaurus'' was initially thought [[Science Marches On|a late-surviving ceratosaur that convergently became similar to an ornithomimid]]. Whereas ''Mononykus'' was identified as a sort of ''running bird'', closer to a house sparrow than ''Archaeopteryx'' was.<br />Actually, the classification of the family has always been very problematic: they have been variably put next to ornithomimids, to troodontids, or to ''Archaeopteryx'' (in this case, they would be the closest bird relatives); this is because their specialized hands made comparisons with other theropods a difficult task. However, the discovery in 2010 of a basal relative called ''Haplocheirus'' with a complete, three-fingered hand has since confirmed alvarezsaurs as non-avian maniraptors. Also note that, since “''Mononychus''” was changed in “''Mononykus''”, most alvarezsaurid genera have since called with the suffix –''onykus'', in a classic [[Follow the Leader]] example. One of them has been found in Alberta, living alongside many popular Late Cretaceous dinosaurs: ''[[Exactly What It Says Onon the Tin|Albertonykus]]''.

* ''Therizinosaurus'' could be considered the [[Non-Identical Twins|Non Identical Twin]] of ''Deinocheirus'': it was a colossal yet awfully bird-like theropod, just like ''Deinocheirus''; specialized to a non-big-prey-based diet, just like ''Deinocheirus''; was discovered in Late Cretaceous rocks from Mongolia, just like ''Deinocheirus''; is known mainly from forelimbs and few other bits, just like ''Deinocheirus''; entered the dinosaur list around the same time as ''Deinocheirus''; and, last but not least, it is another candidate for “the biggest theropod” title, [[Madness Mantra|like]] ''[[Madness Mantra|Deinocheirus]]''! But, '''un'''like ''Deinocheirus'', ''Therizinosaurus'' was not a giant ornithomimosaur -- it was even more bizarre animal.<br />Discovered in the 1950s but recognized as a dinosaur only in the 1970s, its forelimbs were as long and powerful as those of the giant ornithomimosaur. But ''Therizinosaurus'' had an additional curiosity, one that made it [[Always Someone Better|even more awesome]]: [[Wolverine Claws|three scythe-like claws]] on each hand (hence its name, “scythe lizard”), some ''as long as a human arm''. In short, it had the biggest nails known so far within the entire Animal Kingdom. One of these oversized claws was in fact the first known remain, and for the longest of time, [[Science Marches On|scientists thought it was the rib of a giant marine turtle]]. With such poweful weapons, ''Therizinosaurus'' has received in the past the same treatment as ''Deinocheirus''. Some old drawings went as far as to show our “scythe-dino” as a giant deinonychosaur with ''sickle-claws'' on each foot (if ''Therizinosaurus'' was really shaped that way, it would really have been the most [[Badass]] dinosaur one can imagine…).<br />More accurate researches made in the beginning of the 1990s definitively debunked these fantasies: we now know with a good level of sureness that ''Therizinosaurus'' was a bulky-bodied, round-bellied, and quite slow-moving animal, that used its claws mainly to pull down branches. Furthermore, its jaws were arguably weak with a rounded horny tip and small grinding teeth similar to those seen in its relative ''Segnosaurus''. This obviously doesn't lessen its general coolness: even with this new shape, ''Therizinosaurus'' remains an odd-looking, powerful beast, and thanks its massive body, it might even be the biggest and heaviest theropod ever discovered, weighing even more than the famous ''[[Stock Dinosaurs|Spinosaurus]]''.<br />Just like with ''Deinocheirus'', we dino-fans are patiently waiting for new exciting remains of our "[[Wolverine Claws]]-osaurus" being excavated. Meanwhile, a special spinoff of ''[[Walking Withwith Dinosaurs]]'' from 2002 temporarily recreated our imagination in CGI: in the episode titled “''The Giant Claw''” [[Nigel Marven]] talks about ''Therizinosaurus'', [[Lampshade Hanging|lampshading]] its whole [[Science Marches On]] story from a mighty carnivore to a [[Gentle Giant]]. Nigel is in Late Cretaceous Mongolia searching for the possessor of the eponymous “giant claw”, which the zoologist believes to have pertained to a fearsome predator. After goung through several adventures with other famous dinosaurs of the habitat (''Protoceratops'', ''Velociraptor'', etc.), Nigel witnesses a fight between ''Therizinosaurus'' and ''Tarbosaurus'': even though the former unexpectedly reveals itself to be a herbivore, it easily defeats the tyrannosaur by slapping it in the face with its scythe-claws, obligating the predator to flee. Finally, the [[Rule of Cool|therizinosaur licks Nigel’s face]]. Really!

* Most ''[[Stock Dinosaurs|Oviraptor]]'' relatives were small-sized like their group's namesake, except for one: ''Gigantoraptor''. Discovered in Asia only in 2007, this dinosaur, despite its name, is ''not'' an overgrown dromaeosaur: its name means “gigantic thief” (an evident reference to ''Oviraptor'').<br />''Gigantoraptor'' grew up to 25ft in length, almost as big as the neighboring tyrannosaur ''Tarbosaurus'', but with the anatomy of the classic oviraptorosaurs: and if their way of life was hard to decipher, imagine what kind of headscratching Gigantoraptor causde. It's all cool, though: three, generally small-sized lineages of non-avian coelurosaurs have at least one oversized member within their ranks: ''Deinocheirus'' the giant ornithomimosaur, ''Utahraptor'' the giant dromaeosaur, and ''Gigantoraptor'' [[Rule of Three|the giant oviraptorosaur]]. On the other hand, tyrannosaurs and therizinosaurs include ''many'' gigantic species, while other coelurosaurs, such as the troodonts, have none. But who knows? Maybe one day a “Gigantroodon” would be discovered…<br />''Gigantoraptor'' recenly recevied some mild media attention, appearing in paleo-documentaries like ''[[Planet Dinosaur]]'' and ''[[Dinosaur Revolution (TV)|Dinosaur Revolution]]''. It could well be on its way to becoming a new member of the [[Stock Dinosaurs]].

[[Category:Prehistoric Life Birdlike Theropods]]