Avatar Creatures size in 1/6th scale

[Mostly Fantasy]

Hey all- I'm looking for a bit of help with scale. I've found the sizes listed of 3 of the creatures from "Avatar", but can't get a good view of their heads. Basically, I'm making 1/6th scale skulls for the Banshee, Leonopteryx, and Thanator, and need to know how long their heads are. The only comparison chart I've found is way to small to make good measurements from.
Thanks for any help!

 

[d_jedi1]

I'm sure there is probably something out there or someone will have something but if not, the scaling on the figures seems pretty accurate.
I would assume that one could compare and do the math to up-scale the heads.
(Thats how I would do it.)