Luckii said:
The Turtwig line are definately turtles and tortoises.
Definitely*
Also, Torterra certainly has some ankylosaurid traits fused into its general tortoiseness. Disregarding the dome-like carapace along its back, tree and all, note the armor plating structure along its body. That is not a trait taken from anything Testudinidae.
As for sauropods, you do realize they were a
massive group of creatures that had a great deal of internal variation, right? Not all Sauropods were fucknormous. Either way, a lot of Pokemon are different in terms of size (or at least Pokedex sizes, most of which are complete and utter bullshit) to the real world creatures they are actually based on. No one's saying Galvantula is any less of a spider in spite of it being far larger than any Terran spider could ever be, right? Same logic applies to Meganium. It IS based on a Sauropod, get over it. So is Tropius, for that matter. I don't see why that's such a "distant" link.
Also, in terms of design, Tyranitar is pretty much "How close can we get to copying Godzilla and get away with it". So it's kind of an accurate portrayal of the dreaded, mostly-extinct Rubbersuitosaurus.
As Luckii pointed out, Pterosaurs aren't dinosaurs. Neither, however, are Plesiosaurs (although Lapras is definitely based on one, or at least on a common portrayal of the Loch Ness Monster as one). Breloom I can easily see as a dinosaurian creature. Same goes for the Aron/Lairon/Aggron line. the Haxorus line was explicitly stated by Ken Sugimori to be based on certain herbivorous dinosaurs (Iguanodonts, I suspect, although their heads remind me of certain marginocephalians) and certain dinosaurian traits can be seen in many other species.
Honestly It seems to me that as far as official Pokemon that aren't fossils go, Game Freak seems to prefer to stick to extant organisms as their basis for creature designs rather than extinct ones. This may or may not change over time, but who knows really.
And lastly, though this is a matter of nitpicking - there are more dinosaurs in Pokemon than you may think. That is because there are a fuckton of birds. In case you haven't heard,
birds are dinosaurs - the only dinosaurs still living with us today. Gen 5 even gave us a transitive form of sorts in Archen/Archeops. So there's that.