Ok, so, lately I've been hearing rumours about a certain Spinosaurus specimen (a skull, supossedly) known as the Tucson Rock Show specimen, which would be in a private collection and thus not available for study. According to some, this creature had a 2.5 meter long skull, which would supossedly suggest an overall lenght of up to 25 meters long.
In interviews for Jurassic Park III, Jack Horner mentioned a 2.5 meter long Spinosaurus skull so this may be the same specimen, although he didn´t give much info on it.
Here's a scale showing the estimate sizes of several Spinosaurus specimens, the Tucson Rock Show specimen is shown in green. The smaller ones seem to be reconstructed with short legs as suggested by recent finds.
Some say that a 25 meter long Spinosaurus would weigh up to 30 tons, which would render it too heavy and slow. But then there's the question, too heavy and slow for what?
It would certainly not be running at high speed after prey, but did it need to? The latest theories indicate that it was a semi-aquatic animal, so it may have spent lots of time in the water where weight wouldn´t be so much of an issue. Even more, if paleontologists are correct and dinosaurs were much more light weight than usually thought, it may be that a 25 meter long theropod wouldn´t weigh as much as we imagine, and thus not be so greatly hindered by size.
There's also a bunch of Tyrannosaurus rex specimens said to be much larger than currently accepted, including a toe bone that comes from a specimen probably 15 meters long.
Again, many say such a giant would be hindered by its enormous weight, but I believe if it was an ambush hunter it wouldn´t be much of a problem. The larger a theropod would grow, the larger the prey it could catch (and the more attractive large prey would be) so it wouldn´t necessarily be a limitation IMHO.
So I start this thread for two reasons. One, to see if any of you has ever heard about this mysterious giant specimen, and two, to know what you think about the possibility of Spinosaurus reaching such a monstrous size, or even, of any theropod reaching such sizes.