The worst photos feature toys. We'll get to those in due course.
The Diplodocus on the cover is certainly very retro, but it's an impressive photograph nonetheless - the detailing in the sculpt is admirable, and the lush scenery is suitably evocative (actually, it reminds me of the Hawaiian locations used in Jurassic Park, although this book - from 1987 - predates the film by some years). There are a number of other models in this book in a similar style although, unfortunately, we are not given any indication as to where the photos were taken (so if any of you out there in interweb-land can tell me, I'd be exceedingly grateful).
Of course, there's always one animal that seems to come out badly in these situations.