On the one hand you have Pachycephalosauria with maybe a dozen species, many of them very fragmentary, on the other hand you have Theropoda, which has anything from Microraptor to Carnotaurus to Spinosaurus to Therizinosaurus to Tyrannosaurus. And donīt get me started on the diversity of modern birds.
No wonder Tom Holtzīs Dinosaur Encyclopedia has 9 chapters of theropods as opposed to 1-3 chapters for any other dinosaur order.
Well, fuzzy primitive ornithischians are big yes in my book, according to Tianyulong (and the purpoted feathered ornithopod from Siberia) although I'm unsure on what that means for other ornithischians and derived ornithopods from which we have definitive scaly impressions and no signs of feathers.
I'm really sitting on the fence with sauropodomorphs in general though, as well as non-coelurosaurian theropods. It's confusing to think that some theropod clades may have lost their feathers, such as abelisaurids, while others retained them even in great sizes such as tyrannosauroids.
Feathers are so complicated.
Fuzzy primitive ornithischians don't necessarly clash with the evidence of scales in more derived members of the clade, apparently, known dinosaur scales resemble bird scales, which are not homologous with crocodile and lizard scales in neither morphology or development, it's entirely possible that bird "scales" (and dinosaur scales) are actually feather derivatives.
Oh and that was quick, fixing the ankylosaurus! Looks great now ... I wish there was more available about the reconstruction of ankylosaurs and figuring out just where and how all the plates and spikes and bumps all fit in together.
Also ... I did find it jarring to read about *some* classification systems including birds as theropods ... it somehow seemed to remind me of the fringe group that denies birds being dinosaurs. But ... to my mind we shouldn't throw overboard classification systems in which birds constitute an entire class. We can classify things according to different criteria, not only phylogenetic relationships, and one goal I see of classification is to help us remember and understand as many different living things as possible, and for this we can group them in different ways. A strict cladistics classification of all living things would mean we need to throw away pretty much all the labels that we use. Strictly, mammals, birds, reptiles and amphibians will fall under fish, and fish will be classified as who knows what. I personally think we can use 'old fashioned' categories along with new ones ... we can know birds are dinosaurs but still speak of birds, without necessarily getting confused.
I've already changed the wording once in that part of the image, to make it clearer that the dispute is only over what classification system to use, not over birds' phylogenetic position. Do you think the meaning of this part of the image is still unclear? If you do, I'm not sure how to make it clearer than it is already, so I'd like to know if you have a suggestion about it.
I have a few suggestions about selection of species and whatnot, but I've left that over on Aggie's page since I guess that's his arena.
Sorry if I'm being overly critical, since I'm not the target audience or anything! I just think it's a really neat idea for a poster.
I have always taken a great interest in dinosaurs and this is really a well-done collaboration
Anyone who wants to lobby the ICZN to stop using Linnaean taxonomy has my support. But until they do, Linnaean taxonomy and PhyloCode are both valid systems of classification. I don't think it's fair to tell people they're wrong just because they use they the system that the ICZN does, as long as they understand that having Aves as a separate class is just a matter of bookkeeping, and not reflective of anything in biology.
The problem is that this is intended as an educational piece and the way it's worded, to me at least, makes it seem like there is some sort of controversy or that there are competing ideas which isn't really the case. Surely the idea here is to teach the layman about dinosaur phylogeny and I don't feel like it's getting the full message across. Avialae is within theropoda. If it were me I would have gone as far as to include an image of a bird in the infographic. It's not me though, so do what you wish.
There's no real controversy in paleontology over whether birds are phylogenetically nested within theropoda, but you seem to be under the impression that PhyloCode also has already been universally adopted, and that isn't actually the case. It's obviously the most popular classification system in the online paleo community, but if you look in something like an ornithology textbook (I just checked one), you'll see birds still listed in their own class that's separate from Dinosauria. However, I'll change this part of the chart to make it clearer that the controversy is only over classification, not over what the relationships are.
The point I'm making about Jeholornis is that if it's classified in Aves at the class level, it can't also be classified in Saurischia or Theropoda under the same system. The Linnaean rank for Saurischia is an order, and Theropoda is a suborder, so if Aves is going to be given a Linnaean rank and also be nested within Theropoda, its rank has to be somewhere around the family level. I think I may have misunderstood the point you were making about this, so please let me know if I'm not addressing it.
At Wikipedia, the convention is always to present whatever ideas are currently most mainstream and widely-accepted. (Not that articles there always do that, but it's what's they're supposed to do.) That's probably why most of the articles there are still using the Linnaean system. I imagine Matt wouldn't necessarily be using that system if Wikipedia didn't have this rule, but it's still the same basic idea of trying to present whatever idea is widely-accepted, regardless of one's own viewpoint.