Styracosaurus skull for Dinosaur Replicas

Going to start a Styracosaurus skull to add to my Shapeways shop products. I got a bit bored with making dinosaur skulls towards the end of last year but I’ve after wasting some time messing with other (mostly abandoned) projects I’ve got the bug again, surprised it’s took me this long.

I’ll post visual updates my progress here in parallel to threads on Blender Artists and the Dinosaur Toy Forum. Won’t be as in depth as my rex skull from last year.

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Well there’s decent references online for the two main specimens. Going to base my Styracosaurus on the holotype (CMN 344). Found an online copy of Ryan, Holmes, & Russell, 2007 (linked below), a great study with loads of info including a great 3 view drawing which corrects the distortions in the fossil. I’ll also be studying photos found on the internet.

A revision of the Late Campanian centrosaurine ceratopsid Styracosaurus from the Western Interior of North America

I’m going to run up my own scale drawing though. I prefer to do this because I need to learn the shape and sketching it out helps me fix the form in my head.

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Following with great interest!

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Spent the last couple of nights scribbling, some false starts accompanied by plenty of swearing. This is the first of the orthographic drawings (call it revision 3.5) though I might make a ventral view as well.

A few more available online references.

Brown, Barnum; Erich Maren Schlaikjer (1937). “The skeleton of Styracosaurus with the description of a new species”. American Museum Novitates. no. 955: 12. Retrieved 2007-03-29.

Gilmore, Charles W. (1930). “On dinosaurian reptiles from the Two Medicine Formation of Montana”. Proceedings of the United States National Museum. 77 (16): 1–39.

Not much info on the back/underside of styracosaurus skull but nice drawing of Centrosaurus/Monoclonius in the next paper. Apart from the head ornamentation the centrosaurines are very similar so I think I’m OK basing details on this.

Brown, Barnum. A complete skull of Monoclonius, from the Belly River Cretaceous of Alberta. Bulletin of the AMNH ; v. 33, article 34.

Full description of the postcranial skeleton of CMN 344, useful if I decide to do the whole skeleton (has a nice front view skull photo.

Robert B. Holmes, Michael J. Ryan, & Alison M. Murray. Photographic Atlas of the Postcranial Skeleton of the Type Specimen of Styracosaurus albertensis with Additional Isolated Cranial Elements from Alberta

Also accumulating a photo library of Styracosaurus and Centrosaurus skull photos.

Thanks, after a slow start I feel like I’m getting into gear with this.

Can’t find decent reference for the inside of the Styracoasaurus skull but there’s some for the closely related Centrosaurus and much of Triceratops’s inner skull is covered fairly well in published works. I’ve been scratching my head over this for a couple of days but I think I can work around it.

Apart from the signature features of each species there’s a lot of uniformity among the ceratopsian group, especially centrosaurines so these more obscure areas will be based on Styracoasaurus’s cousins. I’m not going to show these parts in great detail anyway because they can only be partly glimpsed through the nose and the orbits but I can sculpt them loosely to show some internal structure.

Ceratopsian heads are highly modified with a huge beak and chewing apparatus at the front and the rear skull elongated into a frill, because of this the back palette and lower brain-case bones are sort of smushed together at the mid point longitudinally. These sketches are my efforts to ‘feel’ my way around the internal skull bones. There’s only so far I can go with drawing, time to dive into some 3D modelling I think.

Not very motivated this weekend but I’m going to make a start putting down some polygons tonight. For the next 3 weeks its Springwatch on BBC 2 so I’m not going to get much creative work done. One of the (many) things I like about Blender is the easy template image setup. Due to natural laziness I make it even easier for scale modelling by making my images conform to a particular size.

For example my Styracosaurus orthographic is drawn at 1/10th scale on a grid 20cm wide. That means I can just crop the scanned drawing on the grid lines and set the background image in Blender to 2 meters, instantly the correct size! The same image is used in both top & side view, I’ve made sure the top view is rotated and centered on the origin.

Been away from this for how long now? 1 week? More? I’ve been spending some time looking at the internals of ceratopsian skulls. Anyway I can only look at 100 year old museum publications for so long so I’ve made a start.

Took a different approach from last year’s rex skull models. Rather than building a sub-D model from the drawing I thought I’d try making a template sculpt first, not intended to be the final model but hopefully that will make sense later on. Starting with a subdivided cube I’ve used Blender’s dynamic topology to create the initial shape, mostly with the SculptDraw and Move brushes. It’s a great tool for free-form sculpting and very easy to add/reduce detail.

Into edit mode to make & bridge holes in the mesh, then back into Dyntopo to refine

That’s the main form mostly laid out, bit more still to do on the underside. Not too refined as it’s a scaffold for the next stage. The inner bones I’ll work out in sub-D polys later.

Added some lightmap UVs on the scaffold sculpt so I could paint this poly map (red lines). It’s mostly a guide and I’m not wedded to it, there’ll probably be changes once I start placing polys.

Looks very well already. Are you in contact with paleontologists to discuss your work? Or are you all on your own on these models?

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All me so far though I’d have no problem with critique from professionals.

Another long absence busy with other stuff, Really need to make a push to wrap this up. I’m setting up a low-poly base model using the painted lines as a guide. With face snapping turned on, it’s easy enough to lay down polygons. There’s a mirror modifier on the retopo mesh but most of the time it’s turned off.

For placing a vertex that’s meant to be on the centre-line I find it convenient just to zero it’s X co-ord manually in the properties panel. Now it’s just a case of working my way around until it’s all built. Always a lot of tidy up required as the model develops, inner bones will need special attention.

That’s the top surface sketched out I think. The most visually important area so I’ve worked this over a couple of times to even up the polygon flow & size as much as I can. Might change a few things yet I’ll see how it pans out.

Blender’s thickness modifier is a quick 'n dirty way to add volume to a surface mesh. In this case it’s perfect for initialising the interior & underside, just to give me a good starting point for editing.

Sub-D parts for the inner (and under) skull bones. Separate objects at the moment, brain-case (purple) and palette/jaw joint (blue).

View from below, just need to tweak the rough shape a bit more then they can be connected into a single piece and welded to the rest of the cranium.

Started the lower jaw mesh, didn’t want to go further on the cranium without it. Not necessarily a mega snug fit when closed but they have to work together, especially at articulation point.

Jaw sculpt 3d traced to sub-D.

Made the mandible teeth as a unit from rectangle with multiple cuts on long axis.

Ceratopsian dental batteries form a cutting edge from many small teeth constantly being replaced from underneath. I can sculpt in some detail later to add some inter-tooth separation.

Now with upper teeth, same method as lower ones. Joined the cranium parts into a single piece, bit more tinkering still to do on this.

Added a small hole between eye & beak. Antorbital fenestrae are almost fully closed up in ceratopsians and filled in in most museum mounts, I’ll sculpt it down to make it even smaller in the detail stages.

Think that’s the poly modelling part mostly done, if I get a move on I could maybe finish the sculpt by the weekend (experience tells me that’ll never happen :)). I’ll leave it alone for now & check it over tomorrow. These’s always a fix-ups after viewing with fresh eyes.

Temporally made the sub_D model multicoloured to help me break it into UV islands. A UV map isn’t needed for a the kind of 3D print I’m aiming for but it’ll be useful for baking normal and occlusion maps for 3D renders, I usually make a few pics for Deviantart etc