My educated guess as to what Godzilla is in this film

In Godzilla 2000 and a few others I'm sure of he fed off energy.
This theory has been around quite some time, and from what the trailer shows he can survive the intial blasts. Which means well we're screwed and Godzilla is unstoppable. On another note, Godzilla inspired Gamera. Godzilla isn't a dinosaur and none of his orgins ties to that theory. If you're talking about the 1998 Godzilla, well this movie has absolutely nothing to do with that film.

Godzilla vs. King Ghidorah 90's was godzilla's backstory (if you choose to believe it)

he was a Godzillasaur hit by nucLear testing Akagi your thoughts are Very believable 

Very believable, probably the best explanation I've heard thus far.

Eh, I really don't like any those dinosaur/really ancient animal explanations for what Godzilla is. I'd much prefer Godzilla to be a mutation of something more modern.

I detailed reasoning for it in a separate discussion, but in summary, it creates a second, UN-NECESSARY layer of disbelief to overcome. 

Like, the fact that nuclear bombs mutated/awoke a creature and it becomes Godzilla (no matter what animal you pick from) is one layer of disbelief you have to set aside.

Picking any kind of extraordinarily ancient animal adds that second layer, because now you need an explanation for both how the nuclear weapons activated the monster, but you ALSO need a separate explanation for how the monster survived for MILLIONS OF YEARS, was exempt from the fossil record, can suddenly breath our atmosphere, adjust to our climate (especially for a reptile climate is important) and so on and so forth. 

It just increases the level of ridiculous absurdity that a viewer has to swallow when Godzilla has be millions of years old. There's no reason for it. It is JUST as likely that a nuke would mutate a crocodile into Godzilla as a nuke would mutate an ancient sleeping dinosaur or whatever into Godzilla. So provided the animal into Godzilla mutation via nuke is equally likely no matter what animal you pick.....why pick an animal whose very existence is also ridiculously implausible?

As mentioned in other threads by other people, I almost kind of prefer when Godzilla's origins are made to be more mysterious and not completely explained. I think it adds to the awe of the creature. But provided they do explain it, I really hope it isn't millions of years old. 

I love the godzilla movies, huge fan. However what I dont get in the godzilla franchise is how it's possible for an prehistoric creature to live that long. Doesn't godzilla die of old age? Howcome godzilla is not discovered earlier in human history? Maybe I am thinking too much in it. I am looking forward to the new movie.

@ERWINGFAN91
"Godzilla's exact origins vary, but it is generally depicted as an enormous, violent, prehistoric sea monster awakened and empowered by nuclear radiation."
It's a fictional franchise about a giant kaiju fighting monsters, destroying cities, ect. Toho didn't worry too much about keeping it real.

Now here is my rational explaination; At this very moment in time we know close to nothing about our oceans and what lies on the bottom, (for all we really know something could really be down there, lol). The nuclear blasts from World War II awaken the sleeping beast from deep in the ocean with the impact of the bombs, and here we are.

One theory people aren't really talking about is the idea put forth in (and i know it's more of a family movie) The Water Horse. In that tale there was only ever one water horse (Nessie) and right before it died it laid an egg that would produce the next animal. I kinda feel like that could apply to Godzilla

no offense, but saying godzilla is precambrian, is really, really silly, heres the knid of animals from that era

Another cool thing about keeping Godzilla's origin's more mysterious, is that it would actually be more realistic that way. 

Like, so let's say we nuke some crap, and Godzilla comes rising out of the ocean. We would have NO IDEA where it came from. Nobody would be like: Yep, that's used to be a crocodile...or yep, that used to be a T-Rex. 

In order for us to know what Godzilla was, before it was Godzilla, we would have KNOW about the creature's existence BEFORE it became Godzilla. 

But if we weren't aware of the creature's existence BEFORE it came Godzilla....how on earth would any scientist able to RETROACTIVELY identify what it came from?

If it came from a creature we didn't know existed....we still don't know it existed just because Godzilla's stomping around.

So yeah, the more REALISTIC take on Godzilla, is honestly to not know what it is. Which helps both realism, and story-telling mystery as a viewer.

@erwingfan

what if they use godzilla to explain ancient myths and stuff like sea serpents, :D

That would be pretty cool actually xD
They already used him to explain the nuclear tests in the pacific

Well, they might consider just keeping his origins a bit of a secret. Which is cool by me. Just like Jordan Swickard said: it's just a movie, not concerned with too many facts. That's the reason we see movies too escape reality.

He's obviously an iguana guys!

Emmerich joke haha

you know they might protray him like what akagi said an ancient dinosaur that lived during the precambrian era. which also if you believe in god and you read the bible it does say in one of the books i forget which book, verse, and chapter it is from but it does talk about the leviathan, not saying that is what godzilla will be refered too but it does make me wonder.

I'll try to put my two cents in as to how this all COULD work (please bear in mind I'm no chemist or biologist or physicist):

Godzilla's mutated body is the result of several centuries or even millenia of mutation post-death of the original creature from naturally occurring radiation, each increasing the creature's lifespan, durability, size, and array of exotic abilities, all incrementally and at the absolute genetic level, thus allowing him to shrug off the likes of nukes, remain physically stable even at his great sizes, and produce such powerful exotic abilities.

Additionally, this makes him functionally immortal, being almost completely self-sustaining due to nuclear organ systems save for an occasional top-off after periods of hibernation. His newly mutated telomeres never shorten, thus meaning his body won't break down like a normal organic being.

Add to all this that this nulcear cell biology can repair impossibly huge amounts of damage, on top of his bodyily composition being extremely dense and strong bellying that of any naturally evolved organic being to withstand his great sizes and proportions, and you have the makings of a "living god".

How about this, it's movie, no matter how realistic they want it to be, a giant fire-breathing proto-saur will never be deemed realistic.  However, a few of you raise a good point, as humans we are limited as to what we know about our planet, we are still learning about the ancient earth and god only knows what else we haven't discovered on this planet buried under our very feet or in our oceans.  True scientists never rule anything out as impossible.

Godzilla Himself:

Thank you!  I'm not here to blast anyone's opinions or get into an argument, but... the precambrian era was completely void of oxygen.  It didn't exist yet on Earth.  The environment was completely anaerobic, meaning only small (for the most part, microscopic) lifeforms had developed.  Even in the realm of giant monsters and mutations, a multicellular organism on the scale of Godzilla could never exist in that era.  Later on?  Perhaps.  But not in a world without oxygen.

"In 1954 we awakened something".....Meaning it was sleeping...Probably for millions of years.

Danzilla93:

You're right. I personally shook my head with a deadpan expression on my face when I read the first sentence of the OP. Godzilla from the Precambrian? No. If anything, the only lifeforms that existed during the Precambrian Era were extremely simple bacteria and unicellular organisms. If I remember correctly, the original film said he was an "amphibious" dinosaur from the late Cretaceous Era (subtitles read "Jurassic", but they referred to a mass-extinction event which ended the "Jurassic"). I'm pretty sure we all know what did come from the Cambrian Era, though. A small, hard-shelled proto-arthropod which evolved and thrived in an anaerobic environment? I wonder what that might be...

i just can't wait till the movie comes out