- Bastilodon, an elephant-sized ankylosaur, with even sharper armor, and a horned head. Its teeth look, well--maybe not carnivorous, but certainly dangerous.
- Carnosaur - A T. rex sized animal with raptor claws on its feet and long arms. Greatest hits of features from big carnosaurs and fast raptor-type dinosaurs (dromeosaurs, for the curious, is the technical name for this group of dinosaurs. Although I'm being a little fast and loose with my dinosaur terminology, I'm actually a fairly technical paleontology nerd.)
- Cold One - a horse-sized dromeosaur, capable of being ridden into battle.
- Terradon - a mean, chunky and robust Pteranodon, with a stronger, meaner bite and stronger meaner claws. Also capable of being ridden by skinks, the small-sized lizardmen.
- Ripperdactyl - Uglier, meaner pterodsaur-like creatures, with sharp teeth and big heads.
- Stegadon - A Triceratops-like creature, with a lot more spikes on its head (basically, it's got every spike every ceratopsian ever had, all jammed into one head.) As if that wasn't enough, it's also got a Stegosaurus style tail, complete with "thagomizer" and sharp teeth in its hooked beaked mouth.
- Salamandars look a bit like more reptilian dimetrodons, but shoot a biological Greek fire of sorts.
- Troglodons are carnosaur-sized animals that shoot venomous spit.
- Razordons are lion-sized lizards that are covered in spines which they can, apparently, shoot out of their body in large numbers to impale enemies.
D&D already has a lot of stats for various dinosaurs. Frankly, I think it's overkill. I'd rather see stats for a few "types" of dinosaurs, and then a few a la carte options to over-the-top them a bit. So, from the SRD (or PRD) or other monster listings of dinosaurs in d20, I'd go with the following as my basics:
- A big-headed meat-eater. Use stats for Tyrannosaurus, which is a huge animal.
- A faster, but big meat-eater. Use stats for Megaraptor, which is a large animal.
- A ceratopsian. Use stats for Triceratops, which is a huge animal.
- An armored herbivore. Use stats for Ankylosaurus (MM2) which is a huge animal.
- A big sauropod. Use stats for Seismosaurus (MM2) which is a colossal animal.
- A large pterosaur. Use stats for Quetzalcoatlus (MM2) which is a huge animal.
- A big swimmer, like a Elasmosaurus, which is a huge animal.
- The Giant crocodile.
Or, you could make any of these animals venomous, including having the ability to spit venom as a ranged touch attack.
If you pay attention to such things, no doubt, this will increase the CR by 1 or 2, or possibly even 3 in some cases--although keep in mind that most animals can only take advantage of so many new abilities in a single combat, so it doesn't necessarily make them more difficult to defeat.