The specs from the site list the length as 27 inches, and if Stegosaurus's length is 21 feet, (21/27)*12=9 1/3. So, if my math's right, its going to be 1/9 scale, which would be huge.
And someone said they wanted to see a finish Krentz 1/40 Tyrannosaurus?
Here's mine, painted by me: