I see you recognize that cold-bloodedness is not a requirement for a "reptile" (one may speak of modern sea turtles' quasi-endothermy, though their metabolisms fluctuate unlike strictly endothermic animals). There is of course contention over the status of sauropod dinosaurs like Brachiosaurus (quasi-warm-bloodedness via gigantothermy), which you brought out to compare to Chikorita. (As an aside, even Meganium wouldn't have the same issues with excess body heat, at less than 2 meters/6 feet in height).
So, it's just that you specifically brought out Brachiosaurus to compare to Chikorita, and then declared that this was the first time two or more starters in a set were based on warm-blooded animals, which is not entirely true as long as one holds that Chikorita's line are supposed to be sauropod dinosaurs. Of course, anyone's entitled to imagine any real-world life form into a given Pokemon. Just checking your real-world facts.
BTW, Wikipedia is not the final word on anything. Far from it. But you knew that already.