Red-eyed dust bunny
I could quibble with a lot of details (over half those "dinosaur" categories aren't) and whew it's dated (though putting feathers on the coelurosaurs more than a decade before the Yixian finds was rather forward-thinking), but yeah... very neat. Statting out specific animals is easier, but not as flexible. Or as fun. Those proto-templates were like toys to play with. The article even attempted to cover the entire Mesozoic, including the therapsids and archosaurs that dominated the land until the true dinosaurs appeared in the middle of the Triassic, the sauropterygians and ichthyosaurs in the seas, and the winged pterosaurs.Dinosaurs get another feature on them. This is one of those things that turns up again and again. They're really trying to go for a definitive take this time, with an epic 18 page article that hopefully will keep people satisfied at least until the next edition comes around. Taking a quite scientific approach to the subject this time, instead of listing tons of discrete species, they decide to give one set of basic stats for each genera, and then show you how to scale things up and down for a whole bunch of variants to challenge groups of various power levels with. Aetosaurs, Anklyosaurs, Carnosaurs, Ceratopsians, Giant sea turtles, Coelurosaurs, Crocodilians, Cynodonts, Deinonychusaurs, Dicynodont, Ichthyosaurs, Labyrinthodonts, Moasaurs, Nothosaurs, Ornithomimosaurs, Ormothpods, Phytosaurs, Placodonts, Pleiosaurs, Pliosaurs, Prosauropods, Proterosucians, Pseudosucians, Pterosaurs, Rhynchosaurs, Sauropods, Scelidosaurs and Stegosaurs. Whew. That ought to keep you going for quite some time, especially if you remember to include lots of variants on each body type as actually existed back then. It includes plenty of advice on how to run a game where dinosaurs feature, either tangentally, or playing a big part, along with lost world areas full of flora from their era as well. A very comprehensive article, that is both well researched, and keeps one eye firmly on making sure you produce a playable game with this stuff instead of getting bogged down in historical detail. While not quite as good as most of the planar articles in sheer epicness and imagination, it's just as good in terms of opening up a milieu further for play, and is in very much the same spirit. Which Is something I do like. Other eras and areas of the world can be almost as alien as other universes, and you can have fantastic adventures while barely traveling in a conventional sense. A very solid article indeed.
Inniss did a good job. Looking back, he picked a good reference. Lambert's A Field Guide to Dinosaurs was probably the best single volume on the subject available until the first edition of The Dinosauria appeared in 1990.