Both the Automatic Weights parenting as well as the Weight Groups created and assigned by hand must, at a certain point, inevitably be edited for several reasons. As we have already seen, the parenting tool didn't do a perfect job, or maybe the transition between different weights is too sharp and must be blurred to smoothly deform the mesh. In any case, the ideal tool for this editing work is the Weight Paint tool.
As usual, let's first prepare the scene to work on:
Gidiosaurus_skinning_01.blendfile and hide the 13th scene layer.