This maybe a little hard for some of you to understand, but the new and the original godzilla is NOT a mutated dinosaur
Godzilla 2014 Forum Topic

godzillafan1995
MemberMothra LarvaeApril 02, 20142769 Views20 RepliesNow before i go and explain/rage about godzilla not being a mutation, i have to say that in the past, on a forum about godzilla being a decendant of a crocidile, some fans did say that originally godzilla was never stated as being a mutaion, at first i did not belive them and was slightly aggresive at them, i think it was Akagi, but then i did rember that they never say that godzilla is a mutaion or that he is even a dinosaur, he is refered by Dr. Yamane as a 'cross' between dinosaurs and marine reptoles which are seperate animals. now we know from the back of the Jakks toy box (SPOILERS).............. that states that godzilla is a creature from an ancient time in earths history where giant monsters like himself existed and the earth was more radioactive.
Now i made this topic becuase there are fans who eat at non fans or other fans who do not belive the 'godzilla is a mutated dinosaur theory' and that the origin story from GvsKK 91 is the legit origin for all the godzilla movies, by that i mean that those fans beive that every godzilla including the original is a mutated 'godzillasaurus' (the name of the fictional dinosaur) even though the godzillasaurs thing was never used after the heisei series ended and the jakks pacific toy box and i think even gareth edwards has said or hinted (i'm not sure) that godzilla himself isn't a mutaion of any animal.
bottom line, the only godzilla's that mutated from either a reptile or a dinosaur are the Heisei Godzilla (a mutated fictional dinosaur) and zilla (a muated lizard)