Limits on the Elemental Petrification spell?

[Grand Paladin]

So what would you all consider the upper limit of a living creature to be affected by the Earth Elemental magic (or equivalent innate power) spell be? There is no size limitation or weight restriction in the spell description, although in the BoM, it does note that supernatural or creatures of magic are not permanently transformed.

Or should there not be an upper limit at all, because the spell decription is fine as is?

I could see a large sized living creature being affected (if saving throw fails) like up to a critter the size of even a Blue Whale (which is kind of arbitrary, I know). But in Rifts, we have dinosaurs such as T-Rex, Apatosaurus, and other dimensional creatures that could be colossal in size. Should these massive creatures be effected by one sucessful Petrification spell?

How about the enormous living spacecraft like the Necron organisms in Phase World? They are specifically identified as not supernatural or a creature of magic, rather a genetically manipulated organism.

[Nekira Sudacne]

There is no reason to assume there is any upper limit, ergo, it can effect any sized organism.