In this movie, Nobita revives a fossilized double-yolked egg that hatches into two feathered dinosaurs. As a paleontologist, I appreciate that this movie clearly took notes on the latest paleontological science and incorporated it into its story. No, not everything in here is scientifically accurate, and there is definitely some embellishment for the sake of entertainment. However, it's evident that the filmmakers went the extra mile in their background research: for example, the dinosaurs that we think almost certainly had feathers are all shown with feathers, the end of the Cretaceous is said to be 66 million years ago and not the outdated 65 million years ago, and there's a scene showing the footprints of a pterosaur and they're obviously referenced from actual fossils of pterosaur tracks (that one really impressed me).
As for the story itself, I was originally apprehensive about how this film would be able to distinguish itself from Nobita's Dinosaur (1980). However, though the beginning plays out in a similar way (probably intentionally so), I felt that the second half of this movie carves out its own niche quite nicely. If anything, the climax here has more parallels with Nobita and the Knights on Dinosaurs (1987) in how it involves the end-Cretaceous mass extinction and reveals that there's no true villain in the story. In a way, I think Nobita's New Dinosaur combines the narrative strengths of those two previous Mesozoic-themed tales. Nobita raising two dinosaurs is a more engaging setup than Suneo running around under the impression that he's hallucinating in Nobita and the Knights on Dinosaurs, whereas the protagonists' actions turning out to have a major impact on the history of life on Earth gives the plot slightly more depth and complexity than the straightforward "boy and his pet" story of Nobita's Dinosaur.
If I have any (non-scientific) criticism for this movie, it may be the cameo from Piisuke, the plesiosaur from Nobita's Dinosaur. Although touching and well-intended, Piisuke's appearance raises some confusing questions about continuity. Some parts of this movie (such as Nobita's friends lacking faith in the possibility that he could find living dinosaurs) imply that it takes place in a separate continuity from Nobita's Dinosaur, but Piisuke showing up, complete with Nobita getting a flashback to their time together, seems to run counter to this premise. The fact that Nobita never fully realizes that Piisuke is there (as Piisuke rescues him while he is drowning and departs before he regains consciousness) might also be disappointing.
