The core of A Concise Natural History works through the dinosaurs major group by group: Thyreophora (including stegosaurs and ankylosaurs), Marginocephalia (including the dome-headed pachycephalosaurs and ceratopsids such as Triceratops) and Ornithopoda (including Iguanadon and hadrosaurs), collectively making up Ornithischia, and Sauropodomorpha (including huge herbivorous dinosaurs such as Apatosaurus) and Theropoda (Tyrannosaurus and Velociraptor, but also all birds), together making up Saurischia.
The approach in this is cladistic. So the "dinosaurs" of the title is taken strictly, with no coverage of plesiosaurs, pterosaurs and other Mesozoic animals often lumped in with dinosaurs by the general public. On the other hand, there is extensive treatment of birds, with chapters on their origins among the theropods (and the evolution of feathers and flight) and on their early diversification. The taxon-focused chapters are built around cladograms, character-based parsimony reconstructions of clade branching with no dates or attempt to reconstruct evolutionary history. And these cladograms also have small print captions with a fair bit of (often anatomically specialised) taxonomic diagnostic detail:
"Derived characters [of Ornithopoda] include: scarf-like suture between postorbital and jugal, inflated edge on the orbital margin of the postorbital, deep postacetabular blade on the ilium, well-developed brevis shelf, laterally swollen ischial peduncle, elongate and narrow prepubic process."
This, however, frees up the bulk of these chapters for discussion of the broader biology of the different groups, of their ecology, anatomy, physiology, social structure, life strategies, and so forth.
"The business end of the ceratopsian mouth was the narrow, hooked, beak-tipped snout, suggesting the potential for careful selection of the plants for food. Individually the cheek teeth were relatively small, but they grew stacked and overlapping together into a single functional slicing block in each jaw, the dental battery."
"Statistical studies of Protoceratops show two populations of adult frill and facial morphologies — strong evidence of sexual dimorphism. Moreover, the frills don't appear too large in juvenile specimens — they only develop when the animals reach 75% of adult body sizes. This suggests that frill growth is coordinated with sexual maturity and therefore that there is reproductive connection to frill size and shape. Sound like sexual selection?"
There's also an entire separate chapter on the topic of thermoregulation, describing the broad range of methods that have been used for probing dinosaur metabolism and concluding that "dinosaurs likely enjoyed a range of metabolic strategies, most or all of them rooted in some kind of at least primitive endothermy".
Three chapters cover patterns and processes of dinosaur evolution invisible to a purely cladistic approach. One looks at their origins — "the very earliest dinosaurs were likely carnivorous, bipedal, and small- to medium-sized. They could have been covered with some kind of simple, down feather-like plumage." — and some theoretical problems in defining the origins of a clade. Another covers the broad changes in dinosaur diversity over the course of the Mesozoic, and their possible connection with the rise of flowering plants. And the final chapter looks at the famous K-T extinction: the evidence for a meteor impact, the paleontological evidence, and alternative hypotheses.
There's also a fun chapter on the history of dinosaur paleontology, highlighting how ideas about dinosaurs (and their definition) have changed with time, but largely devoted to miniature biographies of figures such as Roy Chapman Andrews, Richard Owen, Edward Cope, Othniel Marsh, Louis Dollo, Charles Sternberg and his sons, Barnum Brown, and Franz Baron Nopsca.
Fastovsky and Weishampel convey some feel for uncertainties and unknowns and the current state of research, but don't attempt anything systematic: instead of full references, each chapter has a list of selected readings. There are also chapter objectives, summaries, and topic questions, as well as an overall glossary; these are aimed at students but may be of some use to the general reader. With its general accessibility, A Concise Natural History would be a good choice for anyone wanting an introduction to the science of dinosaurs and a step up from the myriad popular books on the subject.