When Dinosaurs Roamed America (2001, sometimes shortened to When Dinosaurs Roamed, especially outside North America) was the Discovery Channel's first major attempt to cash-in on the dinosaur-documentary trend started by BBC's famous Walking with Dinosaurs. Similar to that program, this also aimed for a Speculative Documentary format, and used CGI to recreate its dinosaurs, pterosaurs, and various other prehistoric animals, placing them into real-life scenery. The stories were told in chronological order, from the beginning to the end of the dinosaurs' reign.Unlike its predecessor/competitor, however, WDRA included short cut-away scenes to paleontologists and at times froze the animation to reveal the skeletal structure behind the animals' skin, using solid facts to explain the science that went into creating the program.Other things that make it different from WWD is the fact that it concentrates purely on American dinosaurs, and condenses its stories into small segments, instead of devoting full episodes to them.While disliked by some due to how quickly Discovery churned it out after hearing of the dinosaurs' marketability from Britain, the product was generally well-received by the viewers, especially compared to some later works, such as Clash of the Dinosaurs and Monsters Resurrected.
The work contains examples of the following tropes:
The Megapnosaurus (Kayentavenator?) suddenly cease their attack on the Anchisaurus. It turns out that the Dilophosaurus has shown up.
Animals Not To Scale: Most likely the result of the animators not paying attention. When the first T. rex shows up, it doesn't seem out of scale with the rest of the animals. But the narration claims it's a juvenile. Later, when his mother appears, she is hulking huge, even compared to the "Anatotitan" which is supposed to be the same size as a rex!
Similarly Megapnosaurus is said to be 10 feet long; how come the not-even 7 foot Anchisaurus is more than twice their size (this could be a case of Science Marches On as the larger Ammosaurus is sometimes considered Anchisaurus)?
Apocalypse How: A Class4 event at the end of the Cretaceous, but interestingly, the documentary also starts with an even larger meteor-strike, that was supposed to represent the great extinction event that ended the Permian and made way for the evolution of dinosaurs in the Triassic. A lesser meteor-related extinction also separates the Triassic and Jurassic.
Failed a Spot Check: The deinonychosaurs fail to notice a forest fire, even when being surrounded by flames.
Behind the Black: And the Ceratosaurus doesn't notice the hulking huge, oncoming Allosaurus either, until it's right on top of it. To the ceratosaur's credit, though, it was off-screen, even if out in the open, plainly visible from all sides.
No Pronunciation Guide: Desmatosuchus and Anatotitan are mispronounced "Demastosuchus" and "Anatatotitan", respectively.
Dubs fared no better. For instance all three Hungarian narrations (yes, there's that many) had trouble deciding where to use soft "C"s and hard "K"s, which lead to mispronunciations like "Koelophysis", "Keratosaurus" and "koelurosaurus" — on the other hand, the third version got Desmatosuchus right for once.
Noisy Nature: For a dinosaur-show, this is almost prerequisite. A particularly glaring example is the Dilophosaurus. Justified in the part where the Syntarsus (now Megapnosaurus) steal his food, since he is trying to scare them away, but for the most part he can't seem to shut up even when he's stalking prey (Ironically, Science Marches On and it is fairly certain most dinosaurs were not incredibly noisy animals).
Prehistoric Monster: Avoided, although the animals do behave as aggressive as its intended audience expects them to.
Science Marches On: The lower arms of the raptors are suspiciously scaly. We now know that they had properly feathered wings.
The theropod hands shouldn't be pronated (kangaroo-like). Their palms actually faced towards each other.
Syntarsus is called Megapnosaurus now, and it may be synonymous with Coelophysis.note To further confuse things, the show's creatures may not be Megapnosaurus/Coelophysis at all, but a distinct creature that may have accidentally been named Kayentavenator.
"Anatotitan" now appears to be synonymous with Edmontosaurus, which does not otherwise appear in the show.
Most of the animals shown would probably be much more colourful rather than just shades of brown or grey.
It's likely a meteor strike was not the primary cause of the Permian or Triassic extinction.
Anchisaurus would have run on two legs; if not have done everything on two legs.
Icarosaurus was not the first reptile to evolve the ability to glide (this is more of Somewhere, a Paleontologist Is Crying as earlier gliding animals like Coelurosauravus and Sharovipteryx were known many years before the documentary's creation).
Ceratosaurus was by no far stretch the last ceratosaur; if anything, it was one of the earlier ones.
Megapnosaurus and dromaeosaurids are now thought to be primarily nocturnal hunters.
Sauropod eggs have been found in Morrison formation, even of Camarasaurus, a sauropod featured in the show.
Dromaeosaurids are now thought to have used their claws for gripping and clinging rather than slashing.
Although Ornithomimus was portrayed with feathers; it is now known they had much more than shown, having fully feathered wings like birds or dromaeosaurids.
It is also depicted as being scaly (all pterosaurs probably had coats of "pycnofibres") and said to weigh only 200 pounds (present estimates put it at over twice this weight).
There is no evidence that female Tyrannosaurus were larger than males.
Grass had evolved by the end of the Late Cretaceous.
The juvenile T. rex are depicted very similar to adults and scaly, while more recent discoveries show they were much more lithe and slender than shown in the documentary (it is said in the documentary that the juveniles' legs were longer but the CGI showed little difference) and may have had a downy coat.
Hadrosaurs could not chew by moving their mouths from side to side, they actually moved their top jaw front to back.
Seldom Seen Species: Desmatosuchus, Icarosaurus, Rutiodon, Anchisaurus, Camarasaurus, Nothronychus, and Zuniceratops.
Sexy Discretion Shot: When the Stegosaurus pair get ready to mate, the camera tilts skywards. This was the only solution, though: we don't really know just how they did it.
Shown Their Work: The scenes of paleontologists inserted in between the dinosaur clips.
Feathered raptors and therizinosaurs.
Small Taxonomy Pools: Averted. Many stock creatures appear, but so do a number of animals that have rarely ever been shown on television, notably the (then) newly-discovered Nothronychus and Zuniceratops, as well as yet undescribed and unnamed Zunicoelurosaur.
Stock Dinosaurs: Coelophysis in the Triassic (the only dinosaur in that segment), along with Allosaurus, Apatosaurus, Stegosaurus, Ceratosaurus and Dilophosaurus from the Jurassic and Tyrannosaurus, Triceratops, "Anatotitan", and Quetzalcoatlus from the Cretaceous.
Too Dumb to Live: The dromaeosaurid attacking the Nothronychus head on, although both survive the attack.