This explanation is almost (but not quite) as stupid and lazy as CJ's link to this article, which he only believes supports his position because he did not read any further than the title.
While I agree that this is a poor (i.e. provably incorrect) explanation of the existence of dinosaurs, the idea that the Earth, as a whole, is an amalgam of older and previously independent parts is cosmologically true. Some Mormon historians have traced this notion back to the early ideas about what it means to organize as a community, and to the development of the concept of 'Zion' -- so it's both cosmological and existential (i.e. cool). And, relative to other Christianities, this notion has provided a substantial amount of conceptual freedom with respect to thinking about the physics of matter -- since there is no inherent contradiction at the idea of 4.3 billion year old rocks. (Paging Colton and babe).
In my youth I was exposed to this explanation of dinosaurs by two different elder Mormon gentlemen. One was trying to use it as a way to quickly disprove a theory of the earth that conflicted with his narrow one. He was defensive, trying to brush something off. The other gentleman used it as a springboard for thinking about the inherent independence of all things, and the temporary, highly contingent nature of our contemporaneity. In other words, the latter was letting the notion
radicalize nature -- a move that I profoundly respect -- while the former repeated a move that you see not only in the majority of religious believers, but in a staggering number of scientists who dogmatically hold to what is "True".
Nature always goes beyond our laws and recognitions. A good rendering of Nature is to regard it as Supernatural.
The point of this post is to tell you that some Mormons have used this "stupid explanation" in ways that are highly constructive -- even if they've discarded it as inadequate for the specific case at hand (dinosaurs) -- using it to move into conceptual terrain well ahead of their time. But, sure, condescend.
