I'd made quite a few assumptions about Dinopedia before actually reading it, most of which turned out to be wrong. The one that bore out was that this is an excellent little book, packed to the gills with genuinely interesting facts, and would be an excellent addition to any palaeo-nerd's library.
So what jolted expectations? Well, to start, and I'm not entirely sure why I thought this, but I was expecting the book to be a more adult-oriented A-Z of palaeontology. In some ways, this is true; the book is configured in alphabetical order. But some letters are skipped, whilst others have multiple entries. I like the alphabetised headings (it makes it much more useful as a reference book), but it would be fairer to say that this is a collection of subjects that interest the author, placed in a vaguely indexable order.
The second is that the book would be adult-oriented, but ultimately still an introductory, child-friendly affair. There's nothing in it that would be objectionable to a kid, but it definitely takes a much firmer, text-book like approach to the subject matter, which means reading comprehension alone is quite high, and you clearly benefit from having a pre-existing grounding in palaeontology or biology.
Neither of these are negatives, really, they're just at odds with what I expected. In fact, in many ways they can both be considered positives. Because the book isn't attempting to hand-hold or pad out a specific formula, it's able to cover a wide array of fascinating topics, in a thorough-but-approachable way. That means even the most experienced amateur will actually learn quite a lot ‒ for a book this small, it packs a real punch in terms of information density!
It also allows Naish to be quite opinionated, both around which subjects/topics are included, and in how they are approached. This is immediately apparent with a foreword that highlights how the author dislikes Linnean terminology, and will instead use the "simpler" model of clades:
I find [the Linnean system] misleading and damaging since it's responsible for all kinds of skewed views on evolutionary history and the diversity of life.
I'll admit, this was a surprise to me, but after a few chapters I think I fully agree with Naish. I'm not used to discussing evolution and natural history in this manner, so it felt jarring at first, but once you get used to the format, it does make a lot of things simpler. Chief amongst those is how it really helps redefine just how much birds are dinosaurs, which is a topic the book tackles particularly well.
I should say, though, that the book is far from being highly opinionated or even controversial. It seeks to present knowledge in as up-to-date a state as possible, and does so with a fairness and balance that can often be missing. Naish's own hypotheses and work in specific areas of study are called out and clearly labelled, rather than simply being presented with the same weight as ideas with much broader consensus, and any subjects that could be considered at all rogue are flagged as such and then discussed in a nuanced, skeptical manner.
The result is an excellent overview of the subject matter, taking into account not just the state of fossil research, but broader subjects, both within scientific fields and the wider public discourse around dinosaurs and other extinct species. That these are paired with great little line drawings (also by Naish), and interspersed with genuinely fascinating anecdotes and material, makes for a superb read.