Man, things're getting kinda tenuous round that family, er, tree. I never knew J T Edson did fantasy novels ('til I stumbled on this), let alone one set amongst the mysterious "Suppliers" (presumably an alien race) and featuring some adopted jungle-master side-branch of the Greystoke family stranded on the *cough* planet Zillikian.
Still, the foreword has a thank-you to the ERB estate, and - quite rightly - to the mighty Philip Jose Farmer, fictogenealogist supreme.
See? I don't even care if "fictogenealogist" is a word.