Thanks, for the pictures, Greg!

I think that most male species of frogs, toads and salamanders that engage in either inguinal or axillary amplexus will display nuptial pads. Inguinal amplexus is where the male grasps the female around the waist (as in clawed frogs and other primitive frogs) and axilliary is where the male grasps the female around the armpits (as in most toads, frogs and treefrogs).

I have two toads, Anaxyrus woodhousii and Duttaphrynus melanostictus, as well as ACFs and Surinam toads. Toads are very cool