I was pretty young when Jurassic Park came out, and it gave me a fear of the dark for years. I was just convinced that Velociraptors were hiding in every bush to jump out and kill me. Still one of my favourite movies ever, though! Nevertheless, I think that the
Dinosaurs entry here is going to be tough to spin out into a long post.
There are some simply amazing pictures on Google, if you search for ‘D&D Dinosaur’, by the way. I dare you to look on there, and then refuse to use them in your games afterwards. I never knew how much I wanted to use them myself until this very moment! For sake of completion, I should note that there is a picture of a Stegosaurus in the book, but it is nothing really amazing or dynamic. Just, you know, a dinosaur.
We get seven statblocks here: Brontosaurus (ginormous herbivore), Deinonychus (Jurassic Park Velociraptor), Dimetrodon (crocodile dinosaur), Hadrosaurus (big herbivore), Quetzalcoatlus (huge bird dinosaur), Stegosaurus (chap with the spine plates and spike tail) and Velociraptor (actual, tiny, version). These seem to be filling the gaps left by the Monster Manual, which gave us the big predators, the armoured herbivores, and the fish dinosaurs. The gap-filling nature of the Volo’s monsters are fairly obvious: we get an animal companion-legal Dinosaur, one that you can ride into battle, a low-CR and medium sized carnivore to fight, and the herbivores to fill out the ecosystem a little. The Quetzalcoatlus is probably here thanks to
Avatar, and the desire to give the players something huge to ride around on, while they attack Yuan-Ti airships or something.
The combat rules are all about what you’d expect. The Quetzalcoatlus has
Flyby and
Dive Attack; the Deinonychus has
Pounce; the Velociraptor has
Pack Tactics. They mainly bite, with some doing Tail attacks instead. Nothing to really get excited about here, as they run essentially the same as normal animals. If you wanted to do a ‘Dinosaur’ campaign, you’ll need to think about what else you’ll put into the mix to spice things up, since these guys won’t be hugely interesting over the long run for sure. But stick some Yuan-Ti in there, some tribes of Grippli, and have the ocean full of Aboleths and Krakens, with their servants coming onto land, and you might have a good plan. I absolutely despise Zombie stories, so I've totally ignored
The Walking Dead, but I understand that the focus of that show is not actually on the Zombies themselves, but on the groups of survivors operating in a world that happens to include Zombes; I would think that this would be your best bet for making a memorable 'Dinosaur campaign' work.