

This is a theory about Godzillas origin. We are assuming that we are in the Godzilla vs. King Ghidorah universe. It says that the King of the Monsters was a late surviving dinosaur called a Godzillasaurus, which was discovered by soldiers, then nuked. This caused the Godzillasaurus to mutate, changing the Godzillasaurus to Godzilla. HOWEVER... it never states it was the only one. For it to be late surviving, it would probably need more of a population, as the only things that would have been able to kill one would be a natural disaster, disease, or starvation. There could have been hundreds more Godzillas out there. Godzilla's changing appearance could be explained by this, as the radiation would have had different affects on all of the different Godzillasaurus's. Let me know your opinion in a reply.

You need to consider that there are multiple godzilla universes. We have the showa series where there is Godzilla and that abomination that came out of that one egg. We have the Heisei universe where he came back from the dead? (I CANT REMEMBER SEND HELP) which also has G Jr., Biollante, and Space G. And every Millenium era G film barring the Kiryu movies, has their own universe. We also have the new American G series, Shin-Gojira, as well as the IDW verse.
I? I am a monument to all of your sins.

Varan04276,
The Heisei Godzilla is a creature mutated from a Godzillasaurus and completely different from the one that attacked in 1954.

And don't forget all of the baby Godzillas, of which there were three, I believe.
http://kaiju.wikidot.com/start

Well including the young Godzillas there are three Godzillas in the Showa series, three in the Heisei, two in the GMK timeline, two in the Kiryu timeline and likely two in the Final Wars timeline... That we know of anyway.
It's possible there are others, but that we know of there seems to be only one Godzilla in the G2K and GxM timelines.

Actually there are three different Godzilla universes: Showa,Heisei and Millenium.Each with it's Godzilla (Not counting Millenium) and with it's own origin.But Millenium has different stories and origins of Godzilla.
"A living nuclear weapon destined to walk the Earth forever. Indestructible. A victim of the modern nuclear age."