Another way for Godzilla from 1954 to ressurect

Kiryu.

a clone maybe 

How did he comeback in GMK? It's never really confirmed it was the same creature, nor was it specified how he returned-- Which I prefer.

^Basically this quote. " First godzilla attack was repulsed, the animal was killed by using a chemical compound. The inventor has since died and his records are lost." Yeah, GMK godzilla is not the 54 godzilla. That means that the bones would have not evaporated. And we all have watched the 54 film, those bones evaporated. Common sense will tell anyone that.

The could go with the Godzilla vs Megaguirus way where I believe he never died to begin with.

BigBadBen,
Yeah, I think there was a subtle misconception amongst the characters that it was the same creature, but subtely revealed otherwise later on. I recall the non-dubtitle quote being a little more clear about that.

It's really never made clear in any film whether it was the same creature or not. Even in The Return of Godzilla the humans act like it is the same creature, though later films of the Heisei series prove that it isn't. I think in GMK it is often assumed that it is the same creature because that version of Godzilla seems to be undead in the first place and at the end it is shown that its disembodied heart is still beating, meaning that in 1954 the entire body could have regenerated from virtually nothing. Even though the first Godzilla's bones evaporated in the original, the Millennium films seem to retcon that. In Godzilla X Megaguirus, Godzilla either survived the Oxygen Destroyer or it was never used, and in the Kiryu saga the skeleton was still intact.

^I've never bought that the GMK Godzilla regenerated from nothing. It's a popular theory based on visual metaphor which tends to go over most young fans' heads. The fact is GMK stood a part from most Godzilla movies in various ways. One of which was that it traded the fantasy-laidened psuedo-science for unapologetic fantasy. The fact that Godzilla existed without any real explaination in GMK worked for the world of that movie and need not any speculation.

I also think the lack of explaination for the second Godzilla in the Kiryu movies works as well. It's simply another Godzilla. No need to go into how he was born because we can go back to Dr. Yamane's final speech in the '54 film to set up the existence of another Godzilla.