Yeah, the stegosaur-hypothesis never made sense, because... err... as we know, the last stegosaur died during early cretaceous, so it's unlikely, that they've survived. The idea, that the Mbielu-Mbielu-Mbielu is, if it exists, a bichir is far more plausible.
Can't await to get the book!
Just one point of a little critique (sorry about that): The dorsal fins should maybe be partly covered with green algae...
Well... to be positive: Wonderful painting! That it shows an adult with a young gives it a great backstory! Is the adult fish the protecting and carying mother?
And I have to say, that the original bichir-idea is brilliant! Never had this idea in mind! Awesome!