marginocephalian

Dinosaur Group D&D Alignments
  • Lawful Good: Marginocephalians (Pachycephalosaurs & Ceratopsians)
  • Neutral Good: Ornithopods
  • Chaotic Good: Non-Avialan Maniraptorans (Therizinosaurs, Alvarezsaurs, Oviraptorosaurs, Dromaeosaurs, Troodontids)
  • Lawful Neutral: Non-Averaptoran Averostrans (Ceratosaurs & Megalosaurs)
  • True Neutral: Non-Maniraptoran Averaptorans (Carnosaurs, Megaraptors, Tyrannosauroids, Compsognathids, Ornithomimosaurs)
  • Chaotic Neutral: Birds
  • Lawful Evil: Sauropods
  • Neutral Evil: Thyreophorans (Stegosaurs & Ankylosaurs)
  • Chaotic Evil: Basal Forms (Heterodontosaurs, Prosauropods, Herrerasaurs, Coelophysoids)
10

Carnegie Museum - Part 3

The first thing to greet one’s arrival to the Cretaceous hall is one of the famous quilled specimens of Psittacosaurus. Across the way are some other Jehol Biota animals, complete with models (like this Sinornithosaurus). They look fairly well, so far as museum models of feathered dinosaurs go—that is to say, they don’t look quite like naked dinosaurs with feathers just glued on. Beside the models are a couple specimens, including this Caudipteryx with feathers and its last meal, preserved in its stomach.

A step ahead is Protoceratops, doing what it does best, whatever that may be, and across from that, Corythosaurus. Just ahead are the heavy-hitters of the Cretaceous exhibit, a pair of Tyrannosaurus rex feuding over a corpse. It’s that of Edmontosaurus, being snarled over by tyrannosaurs because this is all edmontosaurs ever did.

Just around the corner is a rare site in most dinosaur halls, a mounted Pachycephalosaurus at full charge. Next to him are a rogue’s gallery of his marginocephalian buddies, the ceratopsians. From the left clockwise, they're Pachyrhinosaurus, Zuniceratops, Diabloceratops, and Torosaurus. Their more famous cousin, Triceratops, stands a bit further down.

Last on the way out of the dinosaur hall is the recently-named caenagnathid Anzu wileyi. The fossil was discovered 15 years ago, and the holotype at this point was presumably sitting just under my feet. Spooky.

Past here, some Cenozoic skeletons and another photoset.

Pachycephalosaurus wyomingensis

North America, Maastrichtian Age of the Late Cretaceous Period

Two wary rivals size each other up at the end of the dinosaur era. The quills are somewhat speculative, but perhaps not outside the realm of plausibility given the presence of similar structures in other Marginocephalians and more distantly-related Ornithischians.

[Please don’t use or reproduce without permission, and thanks for viewing!]

headless-horsepossum  asked:

Kind of re: your paleoartist mistakes post (which was probably I while ago, I just found your blog yesterday and it's Fantastic): I'm a little foggy on what a fully-feathered dinosaur face would look like. Birds have beaks, so their feathers don't go all the way to their mouths. Did dinosaurs have LIPS?? Were they're faces just Beakier than I had imagined? How far down did the feathers go?

Some dinosaurs did have beaks.  Oviraptorosaurs and ornithominosaurs were beaked theropods with feather-covered bodies, so their snouts were probably bare.  However, they probably looked more like this:

Than like this:

That’s one of my problems with how people like to reconstruct dinosaurs. Dinosaurs are cemented in the popular consciousness as “scaly”, so when it came to light that some of them were feathered, paleoartists tended to just slap feathers on top of an already scaly animal, rather than reconstructing an animal that looked natural.  Now we’ve got all these reconstructions of dinosaurs with mix-and-match integuments, with feathers on some parts and reptilian scales on others, as if paleoartists are holding out hope that the feathers could be ripped off and reveal a reptile underneath.

That’s not to say that dinosaurs weren’t reptilian at all.  One of the features that they might have shared with some modern reptiles is lips.  While the lips of modern reptiles aren’t very prominent, they’re still there; notice how this tuatara’s teeth are fully concealed when its mouth is shut:

Now take a look at this lipped reconstruction of Tyrannosaurus done by John Conway:

Doesn’t look so unnatural, does it?  You hardly ever see a reconstruction like this, though; most large theropods are drawn with their teeth constantly hanging out, as if to emphasize the animal’s monstrosity.

My personal theory is that saurischian dinosaurs (theropods and sauropods) had lips, and ornithischian dinosaurs (marginocephalians, thyreophorans, and ornithopods) did not.  While there’s no fossil evidence of this, consider that sauropods otherwise lacked an efficient method of gripping their food; flexible lips would have assisted them in sucking up plant matter.  Lips would also protect the teeth of large theropods when the mouth was shut.  Ornithischians, meanwhile, tended to have beaks, which would preclude the need for fleshy lips.

Does that sound weird?  Yeah, maybe – but not as weird as scaly-headed half-and-half theropods, at least not from my perspective.

Another note about the reconstruction above: The snout is scaly, but it blends into the feathers of the face.  It’s not what you see on a lot of worse reconstructions - that greyish-beige bird-foot texture, standing out like a sore thumb from the feathers of the head.

Essentially, my argument is this: Don’t reconstruct dinosaurs as looking like sock puppets.  While dinosaur faces may not have been feathered all the way down, and they may not have had any fleshy mouth coverings, their appearance was almost certainly more organic than the monstrosity above.  Compare that to John Conway’s T. rex, and decide for yourself which one looks more like a natural animal - and which one you think was more likely to have really existed.