Welcome!

    Let me tell you a bit about the background of this site:

     If you grew up in the 1980s through the early 1990s, you grew up in the Age of Dinosaur Dictionaries and Encyclopedias.  If you had managed to stick with dinosaurs into the middle elementary school years, when you could read at a decent level, you probably ran across them.  The New Dinosaur Dictionary, The Dinosaur Data Book, A Field Guide to Dinosaurs, Dinosaurs of North America, The Illustrated Dinosaur Dictionary, The Dinosaur Encyclopedia, The Dinosaur Society Dinosaur Encyclopedia, any of a number of "X# of Dinosaurs From A-Z" books (these were more for the younger crowd)...  Even one of the crowning achievements of dinosaur publications from this period, The Illustrated Encyclopedia of Dinosaurs (and its later companion devoted to pterosaurs) has characteristics of this category.  For my money, and not counting Dr. Norman's tome (that was at a level of greatness all by itself), the best was The Dinosaur Data Book, for its wide range of topics.  If its central portion, an alphabetical listing of dinosaurs (and a few things sometimes considered dinosaurs) had been organized like A Field Guide to Dinosaurs, with the dinosaurs described under what were then thought to be their families, it would have been absolutely perfect, but as it was, it made practically the perfect book for a dinosaur-mad fifth-grader.  The Dinosaur Dictionaries dwindled at about the time Jurassic Park (the movie) arrived on the scene, with only the Dinosaur Society's effort left as a major work in this category.  There have been others since then, but none have garnered what I would consider the gold standard: can you go into any well-stocked public library and find them?  The six books I named at the beginning passed that test, although they are now beginning to disappear, with some justification.  They are becoming very out-of-date, mostly being published just before the cladistic revolution and subsequent shakeup of dinosaurs really took hold (extra points for anyone here who remembers reading about "teratosaurids").  It is something of a pity that there hasn't been one really good inexpensive, layperson-friendly "dinosaur dictionary" issued in quite a while; with their short capsule descriptions of every dinosaur known up to the book's publication, including age, location, classification, sometimes size, and interesting facts (sometimes quite dubious), they made excellent first sources for that science report for most kids, and treasured documents for that small minority of oddballs.
    At about the same time the books stopped appearing, the Internet was becoming a force.  Within a few years, dedicated websites began doing much the same things, usually not quite as extensive, but with time a few sites began to stand out, like Dinosauria On-Line, the various incarnations of the Dinosauricon, and Dinodata.  In essence, the Internet has begun to take over the Dinosaur Dictionary niche, with a huge advantage: a website can be ever-updated.  The downside is the impatience felt at once-great sites that begin to lose steam as the authors change focus or lose interest.  You never felt angry at The Illustrated Dinosaur Dictionary because it didn't have Baryonyx; books don't work that way.  However, truly great websites, like the Dinosauricon had been before its in-progress update (and hopefully will be after finishing), and Dinosauria On-Line before it tailed off, are just as good as a Dinosaur Dictionary, in many ways; the authors stay on top of the science, and work hard to make sure they have correct information, and also can address wide-ranging topics.  The trick is finding those truly-great websites.
    I didn't create this site as a Dinosaur Dictionary; it grew up to be one (actually, for the first couple days of its existence, it was based around a formational-faunal format that was very unworkable at that point.  I am very interested in dinosaur faunae, though, so I kept part of the idea for later).  There was probably never any choice; the entries grew from my personal notes, which were first taken from Dinosaur Dictionaries back in the summer of 1995, and were preadapted to become one.  As I looked at it more, I realized that what I have is just such a beast: capsule descriptions of every known (non-avian) dinosaur, some rudimentary classification used mostly as a framework, text written at a popular to semi-technical level, and so on.  It's not perfect, lacking as it does the illustrations of its forebearers, or the wide-ranging topics of discussion (and of course there are topics I'd like to address, but don't have the time to work on the way I think they'd need), but I think that it makes a nice, stripped-down version.  
    I hope that schoolkids who arrive on these electronic shores find good information for reports or just for fun, that the serious amateur can find the entries informative, and that professionals don't find too much to laugh at.  I've spent a lot of time gathering information for the various entries, and checking them for accuracy, especially the newer ones.  There're a few things here that a lot of others don't have, like Protognathosaurus as the world's most unlikely possible therizinosaurian (although I have given that up and put it back with the sauropods), an Opisthocoelicaudiinae (which I think will be supported elsewhere once people get a handle on the various new Asian LK sauropods), and a well-developed Euhelopodidae (which I had kept around partly because MJ-LJ Chinese sauropod taxonomy and systematics are murky, like Morrison sauropods until people got around to reviewing them instead of naming new ones; I'm not so sure it will necessarily remain, although a chunk of its members will probably prove to be pretty closely related, but since no one else was finding it, I decided to dynamite it), but we've all got personal quirks and pet theories.  I've tried to be as respectful as possible with respect to data that a researcher has not yet published formally, so there're a few names you might have seen elsewhere that you won't find described here.  I've cast a good-sized net, and the Earth Sciences library here at the University of Colorado is very good in the professional journal department, so you should feel safe that I've done my homework (although cladistic classification and so forth do not constitute my strong suit; it gets to feeling like being a student of arcane sporting statistics); as always, if you want to know more about something, you should contact me, especially if you have a question about where I got my information, since in the grand tradition of Dinosaur Dictionaries, I don't necessarily have my citations right up front.
    Anyway, welcome to Thescelosaurus!, and I hope you find the site informative and enjoyable!