Yeah, it would be great it it wasn't so obviously from something else, but something really different that it is now. Wouldn't necessarily have to be a huge t-rex roar, either, as that thing seems to be at least part insect or crustacean.

I should think about replacement roars too, as, although I'm not an editor (yet), it is one of the things that bugs me the most about the movie and it wouldn't hurt to give replacement sounds some consideration. (though, if I know where it's from, or if it's a pretty iconic sound, I'm gonna see where it's from every time. :p)