A lot of guidestry to use parts of the animal for judging size. For instance, a Moose's legscan beabout 6.5' long. So if thespread of the antlers are close to that, you may have a 60+ " Moose (5 feet!). Width would automatically come with huge paddles and lots of fingers. If the paddles aren't as long as say the Mooses face, then it would not be very big. Width from ear tip to ear tip (don't know inches) is another good measuring stick.
Good luck.