A parking lot dragon? This sounds familiar. [Assuming not a Dragon of Eden, nor one who farts nerve gas] I believe it is a parable about cause and effect; consistency of the world's state.

A parking garage, poured in modern times from reinforced concrete, might have been found to be structurally unstable during a renovation. If this turned out to be rooted in a massive [dragon, dinosaur, etc] skeleton being embedded in the concrete (As it was being poured?) surely this would be a contradiction, if people (workers, onlookers) witnessed the garage's construction.

There would be evidence from the reinforcement efforts; materials sourced to reinforce it due to structural flaws introduced by the skeleton; wear on the truck tires carrying them, memories in brains etc. If suddenly the skeleton were to have vanished, would there be logical consistency problems with the world state? Quite a thing to ponder!

I would like to clarify that this is purely a thought experiment. It is not possible that any group of people, no matter how secluded, could either A: Will such a reptile into existence while maintaining cosmological consistency, nor B: Remove it from our cosmos after evidence over its existence has propagated.