The blood disappears from the Dilophosaurus' claws after it's killed the Anchisaurus.
After the Ceratosaurus has almost swallowed the young Dryosaurus, the same shot is shown again.
When the Tyrannosaurus charges at the Triceratops group, its foot in the closeup looks totally different than in previous shots.
When the Allosaurus kills the Ceratosaurus, the former appears to be way too big.
When the raptors are roaring at the newcomer, the alpha male is suddenly farther back than the leftmost raptor in one shot, when in every other shot, he's between his two partners.
The Allosaurus is seen attacking Ceratosaurus after ambushing from the side. In reality, Ceratosaurus would be able to see the Allosaurus sooner than shown here and perhaps even react quicker.
The narrator says that Ceratosaurus was the last of its kind. Actually, the ceratosaurs were still around 85 million years later.
The narrator mispronounces several names: he calls the Desmatosuchus "DeMAStosuchus", Anatotitan "AnaTAtotitan", and Quetzalcoatlus "QuetzalcoTAlus".
Since some of the featured animals lacked genuine skeleton reconstructions when the show was made, at times when the x-ray scenes are shown, the skeletons belong to different species than the ones being depicted. This is an error the creators had no control over.
The Quetzalcoatlus model suffers from many anatomical errors, since for some reason the designers and animators didn't use the references that the scientist consultants sent them.
In at least one shot when the Coelophysis walks along a river bank, it has no reflection in the water.
When the crocodile-like Rutiodon blasts out of the water at the Coelophysis, the tip of its tail rises above the surface for a couple of frames, but there are no splashes or anything else that would indicate that it really breaks the surface.
When the Dilophosaurus kills the Anchisaurus, and starts to feed, take a look at the head of the dead animal: it actually rises up into the open jaw of the predator. This particular part of the shot is in fact reversed, because not only does the Anchisaurus's head rise up, the Dilophosaurus also repeats its motions, this time backwards.
In one shot of the Syntarsus pack walking forward in the forest, if you watch the shadows they cast, you can see that they are not moving in unison with the animals themselves. It is possible however that this is not really the case, but the dinosaurs have simply been animated into the air, above the ground - in any case, this is an error.
As a young Triceratops rolls playfully on its back, the large bony frill on the back of its skull sinks into the ground.
In the closeup of the Quetzalcoatlus eating, its left wing is oddly twisted and its hand is stuck pointing upwards.
Although the scientists state the young Tyrannosaur would have a more slender built than adults, it is not very apparent when the adolescent T-rex is first introduced. However, it can be (albeit, very slightly) seen once the mother is shown.
The juvenile Tyrannosaurus is erroneously shown to be the same size as an adult. Thus, when an adult appears, it is extraordinarily oversized.
In one shot, as the Apatosaurus herd is walking in from the screen's left side, there is a mix-up of CGI layers. The shadow of the rightmost Apatosaurus was rendered over the dinosaur walking beside it. But the shadows of the dinosaurs walking in the background appear under their feet.
In the first shot of the Triceratops herd, a few second before the shot ends, the CGI animals seem to "jerk" to the side by a few inches.
The Rutiodon and Desmatosuchus both keep hissing or growling without opening their mouths in some shots.
Right before the leader raptor lunges at the dying Zuniceratops, a loud thunder can be heard but there was no lighting preceding it.
The last segment takes place mostly on a large, open plain with a nearby forest. However, since it was based on the Hell Creek formation, the area would have been a flood plain in real life.
The fourth raptor is chased away by the trio of raptors. At the ends of the segment, all four raptors are suddenly together in a group without explanation.
At certain points, predators trying to ambush their prey make roars as the start running. This makes no sense, it would just give them away too early, allowing for the prey to escape.
At the end of the Early Jurassic scene, the two other Anchisaurus that have long been chased off suddenly appear standing a few feet away from their fallen companion as the Dilophosaurus eats it. This makes no sense, as they have been shown to be afraid of even small predators, fleeing from a group of only three, yet they remain on site while at least six hungry predators are present.
Instead of eating the massive and clearly fresh Triceratops carcass, the Tyrannosaurus decides to give chase to the relatively small Quetzalcoatlus scavenging it. Even the narrator points out that it wouldn't be enough food for it, but it isn't explained why the Tyrannosaurus ignores all the meat right in front of it.