Sexing by skull shape?

[lovenokia]

So I couldn't quite get the angle right, but as you can see these two greens are roughly the same length but have different head shape/size. The one on the left has a much wider head and a longer snout. I've been thinking that the individual on the left is a female, and the one on the right is a male. What do you think?

If your frog is more like the one that is darker than dies that mean it is a male or female?
Sent from my Lumia 900 using Board Express