So he makes his own fossils, huh?

I remember reading somewhere that due to Gen I being an experimental generation, the Dragon-type is reserved only for the Dratini evolutionary line because they are some sort of one-of-a-kind mythical Pokemon storywise. This is why Charizard and Gyarados, despite looking like dragons, are not classified as Dragon-types because they seem to be fairly common creatures in the Pokemon world then, not mythical rare beasts like Dragonite.

This is also the reason why Psychic-types are strong, because Pokemon wasn't really meant to be competitive at that point (actually, it wasn't mean to be competitive until around Gen V) and it's just about who can catch the stronger Pokemon then.

Actually, I'd appreciate it if someone can find that source.