The arctic tyrannosaur Nanuqsaurus uses an outdated size estimate. It is shown to be nearly the same size as its prey, Pachyrhinosaurus, 5 or 6 meters long. More modern estimates make the animal considerably larger, around 9 meters. As the series had already gone into production, this updated estimate couldn't be reflected in the finished show.
When the hadrosaur herd reach the edge of the frozen river (at around 6:38), what looks like a small, green Triceratops toy can be spotted on a rock ledge in the exact middle of the shot. According to the creators it was placed there for a reason, which they have not yet revealed, though some viewers think it's either a joke or was left in the shot by accident.